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This is to certify that the

dissertation entitled

Geochemical Gradients in the Topopah
Spring Member of the Paintbrush Tuff:
Evidence for Eruption Across
a Magmatic Interface

presented by

Benjamin Charles Schuraytz

has been accepted towards fulfillment
of the requirements for

Doctoral degree in Geology

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a/a/g? /

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GEOCHEMICAL GRADIENTS IN THE TOPOPAH SPRING MEMBER
OF THE PAINTBRUSH TUFF:
EVIDENCE FOR ERUP‘I‘ION ACROSS A MAGMATIC INTERFACE

BY

Benjamin Charles Schuraytz

A DIS S ERTATION

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Geological Sciences

1988

ABSTRACT
GEOCHEMICAL GRADIENTS IN THE TOPOPAH SPRING MEMBER

OF THE PAINTBRUSH TUFF:
EVIDENCE FOR ERUPTION ACROSS A MAGMATIC INTERFACE

BY

Benjamin Charles Schuraytz

The Tqmpah Spring Member of the Paintbrush Tuff, southern Nevada,
is a classic example of a compositionale zoned ash-flow sheet that is
inferred to have resulted from eruption of a compositionally zoned
magma body. Geochemical and petrographic analyses of whole-rock tuff
samples indicate that the base of the ash-flow sheet and the dominant
volume of erupted material is composed of crystal-poor high-silica
rhyolite, with a gradational transition into overlying crystal—rich
quartz latite. These compositional variations are consistent with a
model of progressive eruption of a stratified magma body in which
relatively cooler, crystal-poor high-silica rhyolitic magma overlay
hotter, crystal-rich quartz latitic magma.

Major and trace element chemical analyses of glassy pumice samples
and microprobe analyses of coexisting silicate and oxide phenocrysts
from within the pumice samples provide closer approximations to the
chemical and thermal gradients within the inferred magma body. The
magmatic gradients inferred from these data indicate that the
transition from high-silica rhyolitic to quartz latitic magma within
the chamber was abrupt, rather than gradational, with a distinct

liquid-liquid interface separating the contrasting magmas.

Benjamin C. Schuraytz

Compositicnally and texturally distinct pumice types are present
throughout the ash-flow sheet. The degree of heterogeneity within and
among the pumice samples increases with increasing stratigraphic
height, and becomes most pronounced in the uppermost quartz latite,
where the diemical variability among the pumice samples is as great as
that of the entire ash-flow sheet.

The observed heterogeneities among the pumice samples of the
Topopah Spring Member are consistent with predictions of fluid dynamic
models in which the velocity field developed near the entrance region
of the vents results in simultaneous withdrawal of magma from a
progressively greater lateral and vertical extent within the chamber,
thereby forming a pyroclastic deposit that becomes increasingly
heterogeneous with increasing stratigraphic height. The abrupt
transition to chemically variable pumice types, dominated by those of
quartz latitic composition, implies that the interface between the
magma layers remained relatively stable until drawdown breached the
interface and preferentially erupted higher temperature, more mafic
magma along with subordinate amounts of the incompletely exhausted

high-silica rhyolitic magma.

ACKNOWLEDGMENTS

I thank my supervisor, Thomas Vogel, who is largely responsible for
initiating my interest in igneous processes and my commitment to
geologic research, and to whom I owe a debt of gratitude for his
continued encouragement and support as a teacher, a colleague, and a
friend. Special thanks are extended to Kazuya Fujita who spared no
effort in his guidance and support, and whose enthusiasm for science
and teaching, even in the wee hours of the morning, will always be
remembered and appreciated. I am especially grateful to my committee
members, Thomas Vogel, Kazuya Fujita, John Wilband, and David Long, for
their helpful reviews and criticisms of this manuscript. I also wish
to thank William Cambray for his support through the Department of
Geological Sciences at Michigan State University and for sharing his
keen field observations during my undergraduate years.

Financial support for this research was provided by the Nevada
Nuclear Waste Storage Investigation Project and the Nuclear Test
Containment Program at Lawrence Livermore National Laboratory. This
was made possible through the efforts and interest of Leland Y ounker,
to whom I am particularly grateful for his insightful discussions
throughout this research project. I also wish to acknowledge the
following LLNL personnel: Frederick Ryerson and Kevin Knauss for
assistance with the electron microprobe analyses, Robert Heft for

providing INAA, and Jan Brown for assistance with sample preparation.

ii

I am especially grateful to Frank Byers, Jr. for convincing me to
focus my dissertation research on the Topopah Spring Tuff, and for
sharing his vast experience during several excursions to the
southwestern Nevada volcanic field during my tenure as research
assistantatlosAlamosNatimalIaboratory. Ialsowishtothank LANL
scientists David Broxton and Richard Warren, and Robert Scott of the
U.S.G.S. for many stimulating and helpful discussions in the field, and
Wayne Morris of LANL for financial support during the summer of 1985.

Many people were extremely helpful to me during my studies at
Michigan State: I am indebted to John Wilband and Bill Monaghan for
their expert assistance with computer software; I thank Loretta
Knutson, Cathy Caswell, and Mona Kindell for their skill in cutting
through red tape, and Diane Baclawski for assistance in the library.
I benefited greatly from discussions with my fellow petrologists, Tim
Flood, Jim Mills, Tim Rose, Carolyn Rutland, and in particular, Steve
Mattson, to whom I owe many thanks. I also benefited from interactions
with my fellow students and friends over the years, in particular,
Susan Bullen, Bud Moyer, Jim Newberry, Dave Cook, Cindy McMullen, and
Soo-Meen Wee. I extend my deepest appreciation to my dear friend
Frederick Kaplan.

I am grateful to Dan and Sue Steinberg for their warm hospitality
during my visits to Livermore, and to Debra Steinberg for her
inspiration at critical moments.

Most of all I thank my parents, Irving and Aline Schuraytz, and my
family, for their unfailing encouragement and support, and for

instilling in me the importance of a good education.

iii

worm

LISTOFm.................................... ................ v
IISI'OF Hm... ..... .............. ............................ vi
mm................................... ..... .. ............ 1
GENERALGEDIQSICREIATIQB... ..................................... 6
m.................................. ........... . ............ 12
Sanple Selectimlz
AnalyticalProcedure ........................................ 15
RESUL'IS........... .......... . .................................... 30
MajorElement Chemistry... ..... . ............................ 30
Coexisting Iron-Titanium Oxides and EStimated Tapereb1res..43
SilicatePhenocrystandGlassChemistry ..................... 53

81mm....... ....... O. ...... O. OOOOOOOOOOOOOOOOOOOOOOOO 54

WCOOOOOOOOOOOO0.00.00.00.00 OOOOOOOOOOOOOOOOOOOOO 65
MIMOOOOCOOOOOCOOOOOOOOO .............. ... ........ 69

Feldspar ...... . ......... 71
m......................... OOOOOOOOOOOOOOOOOOOOOOOOO 78
OtterMineralVariatims....... ........................ 82
DISGJSSICN ....................................................... 83
Originoftbenmiceneterogeneity........ .................. 83
Evidenceforaliquid-liquid Interface....... ........... ....89
MUSIQISHHU ..... . ......... ...... ........................... 92
APPENDIX: MicroprobeAnalyses ofmenocrysts .................... 93

REFERENCESCI’I'ED" .................. .... ........................ 141

iv

Table
Table

Table
Table
Table
Table
Table
Table
Table

8.

usrorm

Precisicn and Accuracy of Chenical Analyses... ......... 17
Chanical Analyses of Imole Rmices

arriilnle-rock‘l‘uffs ........ 18
Micrqarobe Analyses of Ilmenite and Magnetite .......... 93
MicrqarobeAnalyses of Biotite.......... ............. .106
MicroprobeAnalyses of Pyrcnnerxe.......... ............. 119
Microprtbe Analyses of Hornblende... .................. 126
Microprobe Analyses of Plagioclase... ............... ..127
Microprobe Analyses of Sanidineu ................... ..132
Microprobe Analyses of Glass. . ....... . ................ 138

LISTOF FIGURES

Figure 1. Distribution and thickness of the Topopah Spring
Manner of thePaintbrush'quf (Iimnetal., 1966). Locations
of measmed sectiors and dismically analyzed samples indicated
bytwoletterID’sasfollows:BB=BustedButte:CP=311Wash:
IW=IathropWells:GU=USW-GU3drill hole ......... 8

Figure 2. Measured sections of the Topopah Spring Mather,
showing variatiors in depositional mits, welding zcmee, and
crystallization zones (Linen et al., 1966). Nunbers on the
rightofeadisectioncorresmondtothesanplemmberof

dynamically analyzed specimens in Table 2 .............................. 9

Figure 3 . Variation of major elenent oxides with stratigraphic
height. Analytical data fran Table 2 . Solid symbols 2 whole
panics: open synbols == whole-rock tuff. (A) Busted Butte:

(B) 311 Wash: (C) Iathrop Wells; (13) USW-GUB......... ................ 31

Figure 4. Variatim of najor elanent oxides vs. silica. Units

in weight percent. Solid symbols = whole pumice: open synbols =
whole-rock tiff. Source of analytical data: squares from Table 2
diamonds from Lipnan et al., (1966) ...... . ........................... 34

Figure 5. Cronkite-normalized REE aburrlances (log scale) vs.
atcmic nunber. Solid synbols = whole pumice: open symbols =
whole-rock tuff. (A) All samples; (B) quartz latite (low-silica
rhyolite); (C) high-silica rhyolite ........ 37

Figure 6. (‘hondrite-nornelized REE patterns in relation to
stratigraphic position. Solid symbols = whole pumice; open
synbols = whole-rock tuff. (A) Busted Butte; (B) 311 Wash:

(C) Iathrop Wells; (D) usw-cm ....... ...... ...... . .......... 39

Figure 7. Trace element abundances (ppm) vs. silica (wt. 3;).
Solid synbols = whole pumice; open synbols = whole-rock tuff ......... 41

Figure 8 . Inter-element variation of selected trace elements
(ppn) . Solid symbols = whole pumice; open symbols = whole-rock
tuff ..... . . . . . . . . . ......... . ......... . ............................... 42

vi

Figure 9. Fstinated quench temperature and oxygen fugacity

determined from coexisting ilmenite and magnetite memcrysts.

MD, NNO, and PM: indicatetheexperimental buffer curves for

MrO-Mn304, nickel- nickel oxide, and fayalite—magnetite—
,respectively, at 1 bar total pressure (Haggerty, 1976) ....... 49

Figure 10 . Estimated quench temperature of sanples in relation

to stratigraphic position in the ash-flow sheet. Solid symbols

= whole panics; open synbols = whole-rock tuff. (A) Iathrop

Wells; (B) Busted Butte: (C) 311 Wash: (D) USW-GU3. .................. 50

Figure 11. Chanical variation with estimated quench
taperature. 8102 in weight %, all other elanents in ppn.
Solid synbols = whole pumice: quen synbols = whole-rock tuff ......... 51

Figure 12. Histogram of Mg# for 617 biotite phenocrysts frcm 24
pumice sanples, calculated fran microprobe analyses in Table 4 ....... 56

Figme 13. Mg# of biotite phenocrysts within pumice samples in
relation to stratigraphic position in the Busted Butte section ....... 57

Figure 14 . m of biotite paeroerysts within pumice samples in
relaticn to wiiole-pumice sio content, estimted giernch
taperature, and stratigraphic horizon (U supper leve1;L =
lower level). An asterisk following a sanple name indicates a

camined sanple of texturally identical pumices (see text) ........ 58
Figure 15 . Omnositional variations of pyroxene phenocrysts
within pumice sanples; data fran microprobe analyses in Table 5......66

Figure 16. m ofpyrmaenegiemcrystswithinpnnice sanplesin
relatim to whole-pumice content, estimated quench
tanperature, and stratigraphic10 izon (U =upper level; L =
lower level). An asterisk following a sanple name indicates a
carbined sanple of texturally identical pmices (see text) ........... 67

Figure 17. Histogram of M31) for 307 pyroxene phenocrysts from
14 pumice sanples , calculated frun microprobe analyses in
mle 5.0.0.0.........OOOOOOOOO......OOOOOOOOO ...... .0... 000000000000 68

Figlne 18. Histogram of Mg# for 22 hornblende phenocrysts from
4 mice samples, calculated fran microprobe analyses in Table 6 ..... 70

vii

Figure 19 . Zoning profiles in plagioclase phenocrysts from
mice sanples. Each ternary diagram represents a single
Wet. Iargeopensquares=edgeanalyses:snellasterisks

E
1

Figure 20. Zoning profiles in sanidine phenocrysts frcm pumice
sanples. Each ternary diagram represents a single phenocryst.
Iargeopensquares=edgeanalyses: snallasterisks=center

analyses ............................................................. 75

Figure 21. Cmpositional variations of microprobe edge analyses
of feldspar phemnrysts within pumice sanples. Data from Tables

7&8000000000 OOOOOOOOOOOOOOOOOOOOOOO 0...... ......... O OOOOOOOOOOOOO 77
Figure 22. Histograms showing carpositicmal variations in

titanium in the bubble walls of pumice sanples . Ti caticms
calculated on the basis of 32 oxygens fran microprobe data in
Table 9. Light colored square on baseline shows the carposition

of the whole-pumice calculated on the same basis frcm the data

in Table 2 ........................................................... 79

Figure 23 . Histogram showing cmpositional variations in
alminum in the bubble walls of pumice sanples. Al cations
calculated cm the basis of32mcygensfranmicroprobedatain
Table 9. Lightcoloredsquareonbaselinestmrsthecmpositim
ofthewhole—punicecalcnlatedonthesamebasisfrunthedata
inTable 2...... ................. ............ . ............. 80

Figure 24. Cross-sectional cartoon of a layered magma body.
Circles represent cross-sections through hyperbolic eruption
isochrons (Blake, 1981) , indicating the locus of points within
themgnadianberofmgmathatwillread‘lthevent

simltaneously. ...................................................... 85

viii

INTRO DUCTION

The common occurrence of systematic compositional and mineralogical
zonations within ash-flow sheets provides strong evidence that their
source magma bodies were chemically and thermally zoned (for reviews
see Smith, 1979: Hildreth, 1981: Mahood, 1981: Bacon et al., 1981:
Crecraft et al., 1981: Baker and McBirney, 1985). Recently, interest
in how zoned magmas evolve and erupt has focused on the fluid dynamic
aspects of magma chambers. The results of scaled laboratory
experiments using aqueous solutions have been used to suggest that the
interfacial effects of compositionally and thermally contrasting fluid
layers may be important in the differentiation of magmas (Huppert and
Sparks, 1984: Sparks et al., 1984; Huppert et al., 1984; McBirney et
al., 1985; Baker and McBirney, 1985). Theoretical studies of magma
withdrawal during eruption indicate that magma from different depths
within the chamber will erupt simultaneously and that ash-flow
stratigraphy will not simply represent the inverse of the zonations
within the magma body (Blake, 1981; Spera, 1984). The purpose of this
study is to evaluate key assumptions and predictions of these fluid
dynamic models using geochemical data obtained from pumice samples
collected from a well known zoned ash-flow shed: -- the Topopah Spring
Member of the Paintbrush Tuff. The specific questions addressed herein
are: (1) To what degree does the compositional zonation in the Topopah

Spring Member represent the inverse of the compositional zonation in

2
the magma body? (2) Was the zmation in the magma body characterized by
continuous gradients within a single liquid or by discontinuous
gradients within discrete liquid layers separated by a distinct
interface. A major emphasis of this study is placed on the
heterogeneities among pumice samples that have been observed within all
stratigraphic horizons throughout the ash-flow sheet. With few
exceptions (Lipman, 1967: Byers et al., 1968: Noble et al., 1969: Rose
et al., 1979: Wright and Walker, 1977; Fridrich and Mahood, 1987), this
important feature has received sparse attention in previous studies.

It has long been realized that ash-flow tuffs and associated
mlderas result from the explosive eruption and partial evacuation of
large volumes of magma at single points in time (Williams, 1941; Smith,
1960) and that the chemical and mineralogical variability of these
mffsmaybeusedtoinferpre-eniptivemagmaticcmditims. Among the
first to establish this premise was the study by Lipman et al. (1966)
of the Topopah Spring Member of the Paintbrush Tuff. A notable feature
of this voluminous ash-flow sheet is the systematic variation in
composition with stratigraphic height. The zonation from nearly
aphyric high-silica rhyolite upward into phenocryst-rich quartz latite
was first described by Lipman et al. (1966) and interpreted by them to
reflect the compositional zonation of magma in the source chamber prior
to eruption.

Subsequent studies of this (Noble and Hedge, 1969: Lipman, 1971;
Lipman and Friedman, 1975) and other compositionally variable ash-flow
sheets have provided a considerable base of chemical, isotopic, and
mineralogical data (for reviews see Hildreth, 1981; Baker and McBirney,

1985). This information has been used to estimate compositional and

3

thermal gradients inferred to be present in the magma chambers. It is
these inferred gradients that are fundamental in evaluating various
magmatic differentiation mechanisms thought to operate in high-level
magmatic systems. The importance of precise reconstruction of the
eruptive sequence (and the inferred thermo-chemical gradients) cannot
be overemphasized if quantitative tests of differe'rtiation and eruptive
mechanisms are to lead to meaningful conclusions.

It is axiomatic that a stratigraphic sequence preserves
depositional order. This fact combined with the progressive
compositional variation observed in ash-flow sheets promotes the tacit
assumption that "These systems are normally tapped from the top down."
(Smith, 1979, p. 18). That is, the lowermost portions of the erupted
sequence are derived from the upper part of the magma chamber and
overlying products are derived from successively deeper levels. For
example, Cox et a1. (1979) state that "It is essential, in order that
the evidence be preserved, that the eruption is not accompanied by
excessive mixing of magma from different parts of the chamber. That
zoned magma chamber sequences exist at all implies also a lack of
convection in the chamber." (Cox et al., 1979, p. 273). This is
undoubtedly true with regard to large scale convection, and it should
be noted that the authors of the above statement were aware of
additional complexities and limitations (Cox et al., 1979, p. 275).

The complexities and limitations referred to above are discussed in
a detailed study of an ash-flow sheet from the Aso caldera, Japan
(Lipman, 1967). Lipman demonstrated that bulk compositions of these
tuffs deviate significantly from original magmatic compositions due to

eruption, emplacement, and post-emplacement processes. He cited as

4

evidence both chemical and mineralogical heterogeneities within and
among individual pumice samples and noted that similar complexities
characterize ash-flow tuffs in southwestern Nevada and are probably
wideqmead in other ash-flow fields as well. These features, and the
conclusions Lipman drew from them, clearly indicate the need to
understand the dynamic processes involved in ash-flow eruptions in
order to properly assess the primary character of their quenched
products.

Recent interest in the fluid-dynamical processes involved in
high-level magmatic systems has prompted research and the development
of models dealing with input and replenishment of magma (Eichelberger,
1980: Huppert and Sparks, 1980: Huppert and Turner, 1981: Huppert et
al., 1982b, 1984), internal magmatic differentiation processes (Chen
and Turner, 1980: Huppert et al., 1982a: McBirney and Noyes, 1979:
Sparks et al., 1984: Turner and Gustafson, 1981: Turner et al., 1983:
McBirney et-al., 1985: Baker and McBirney, 1985), and dynamics
associated with eruption and magma withdrawal (Wilson et al., 1980:
Blake, 1981; Schuraytz et al., 1983; Blake and Ivey, 1986a, b; Spera,
1983, 1984; Spera et al., 1986: Wohletz et al., 1984). The
applicability and refinement of these experimental and theoretical
models to real systems, however, will require continual geological
observation and testing with field evidence.

The Topopah Spring Member of the Paintbrush Tuff is a classic
example of a compositimally zoned ash-flow sheet for which the field
relations are well constrained and for which substantial documentation
of characteristic features is available. This study presents new major
and trace element chemical analyses and microprobe phenocryst analyses,

5
primarily from samples of glassy pumice. The purpose of these analyses
is to determine if there were continuous gradients or discrete,
discontinuous zones in the magma body that erupted the Topopah Spring
Member. A recurring theme throughout this thesis is the nearly
ubiquitous occurrence of chemical heterogeneities among individual
pumice samples. While this feature may be a hindrance in that it may
obscure primary magmatic variations, it also provides information that
cznbeusedtoevaluatedynamicprocessesassociatedwithpetrogenesis.

GENERAL GEOLOGIC RELATIONS

The Topopah Spring Member (Figure 1) is the lowermost formal unit
of the Paintbrush Tuff, a major effusive sequence associated with the
Timber Mountain-Oasis Valley caldera complex in southern Nye County,
Nevada (Byers et al., 1976). This caldera complex is a major part of
the southwestern Nevada volcanic field which was active during the
upper Tertiary period. Eruptive activity occurred contemporaneously
with extensional basin-range normal faulting (Christiansen et al.,1965:
Lipman et al., 1966; Ekren et al., 1968: Christiansen et al., 1977).
The Timber Mountain-Oasis Valley caldera complex is comprised of four
overlapping and superposed volcanic centers (Byers et al., 1976) ,
recording evidence of repeated eruptive activity of a high-level
magmatic system from 16 to 9 m.y. ago (Kistler, 1968: Marvin et al.,
1970).

The Paintbrush Tuff consists of genetically related bedded tuff and
ash-flow tuff sheets that were erupted 13.2-12.5 m.y. ago from the
Claim Canyon cauldron center,* the southernmost part of which is
exposed in an arcuate segment along the south side of the Timber
Mountain-Oasis Valley caldera complex (Byers et al., 1976). In
ascending stratigraphic order, the four major units of the Paintbrush
Tuff are the Topopah Spring, Pah Canyon, Yucca Mountain, and Tiva

Canycn Mariners. Both the Topopah Spring and Tiva Canyon Members, which

 

* Christiansen et al. (1977) present the alternative view that the

Yucca Maintain and Tiva Canyon Members may have been erupted from an
overlapping area including the Oasis Valley cauldron segment, centered
slightly northwest of the Claim Canyon segment: however, the Claim
Canyon segment did subside during eruption of the Tiva Canyon Member.

7
are the most voluminous ash-flow sheets, are compositionally zoned from
high-silica rhyolite to quartz latite" In contrast, the Pah Canyon
and Yucca Maintain Members are volumetrically smaller by several orders
of magnitude and lack extensive compositional zoning. The Pah Canyon
Member is lithologiczlly similar to the quartz latitic caprock of the
Topopah Spring Member, and the Yucca Mountain Member consists of
uniform high-silica rhyolite similar to that at the base of the
overlying Tiva Canyon Member. These four ash-flow sheets and
associated lavas are thought to record repeated volcanic activity of a
single evolving magma chamber that was part of a larger high-level
magmatic system. In this context, the Topopah Spring Member represents
the tapping of this chamber during a relative "instant", early in its
evolution.

The Topopah Spring Member is a multiple-flow compound cooling unit
that is inferred to have originally covered an area of 1,800 kmz,
with an extracauldron volume of 170 km3 (Lipman et al., 1966). An
unknown volume of tiff, inferred to be buried beneath the Claim Canyon
cauldron, led Byers et al. (1976) to suggest that the total eruptive
volume was probably greater than 250 km3. Estimate of the total
eruptive volume, however, has been recently revised upward to 1,200

km3 (Scott et al., 1984: F. M. Byers, Jr., personal communication,

 

* The compositional designation of quartz latite and the term caprock

synonymously refer to the uppermost sibunit of the eruptive sequence,
that is more mafic and crystal-rich than the underlying subunits, and
commonly forms an erosion resistant ledge (Lipman et al., 1966: Byers
et al., 1976). However, Christiansen et al. (1977) point out that this
uppermost subunit contains a much lower Ca/(Na+K) ratio than typical
quartz latites and plots in the rhyolite field of the classification
scheme of O’Connor (1965).

 

  

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EXPLANATION

t Location of measured section

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— — — Limit of isopaeh information

Figure 1. Distributim and thickness of the Topopah Spring Member of
the Paintbrush Tuff (Lipman et al., 1966). Locations of measured
sections and diemically analyzed samples indicated by two letter ID’s
as follows: BB = Busted Butte; CP = 311 Wash: LW = Lathrop Wells;
GU = USW-GU3 drill hole.

Lathrop Well: Busted Butte USW GU3 311 Wash

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EXPLANATION

m (a) (3:

DMVIONAL UN"! MLDINO zones cannula-non zones
emu-mu «um um- and: W m cm
GE pmiamdavmeummm E23 Pmlyweldd Emma.
E CI'yud-ooorrhvoim m Manama“ mem

(locally W flew units) Dandy wowed ”I; Lithoohveei

E Adi-mm:

Figure 2. Measured sections of the Topopah Spring Member, showing
variations in depositional units, welding zones, and crystallization
zones (Lipman at al., 1966). Numbers on the right of each section
correspmd to the sample number of chemically analyzed specimens in
Table 2.

10
1985), making the Topopah Spring Member the most voluminous ash-flow
sheet of the Paintbrush Tuff. Figure 1 includes the inferred
distribution and thickness of the Topopah Spring Member.

Field relations and characteristic lithologic and petrographic
feamrs cf the Topopah Spring Member have been thoroughly described by
Lipman et al.. (1966). Because the majority of samples analyzed in the
present study were collected from outcrops that have been previously
described, only a brief summary of the characteristic features noted by
Lipman et al. (1966, p. F's-11) is presented here. The Busted Butte
section (Figures 1 and 2) is representative of the Topopah Spring
Member and serves to illustrate the zonal variations in composition,
welding, and crystallization.

At Busted Butte, the base of the ash-flow sheet directly overlies
genetically related bedded ash-fall material and consists of a
3-m-thick zone of light colored nonwelded pumice and ash. Above this
zcne, there is a gradational increase in the degree of welding with
increasing stratigraphic height which is evident by the presence of
collapsed pumice fragments and darkening of the shard matrix. This
zme grades upward into a lS-m-thick densely welded vitrophyre in which
the pumice fragments, occurring as black fiamme, contrast against the
dark grey shard matrix. There is an abrupt transition at the top of
this lower vitrophyre into overlying densely welded crystalline
(devitrified) tuft. Above this transition is approximately 145 m of
densely welded devitrified tuff that contains several lithophysal zones
and in which two depositional contacts between flow units have been
identified. The 170-m thickness of tuff described thus far constitutes

approximately 90% of the total thickness of the Busted Butte section.

11

This entire thickness is composed of high-silica rhyolite (77-74%
3102) which contains a major phenocryst assemblage of alkali
feldspar, plagioclase, biotite, and opaque oxides that increases
uniformly upward from approximately 1 to 6%. Within the next 5 m,
there is a progressive change from myolite to quartz latite along with
a considerable increase in the percentage of phenocrysts. In the
remaining 15 m, the total phenocryst assemblage increases to about 21%
with the addition of minor amounts of clinopyroxene, quartz, and
hornblende, and the whole-rock silica content decreases to
approximately 69 wt%. Approximately 4 m above the transition to quartz
latite, there is an abrupt change from devitrified tuff to a 3-m-thick
upper vitrophyre. The upper vitrophyre grades upward into partly
welded and nonwelded tuff, where the upper contact of the Topopah
Spring Member is sharply overlain by ash-fall material.

The thicknesses of these various subunits vary laterally throughout
the ash-flow sheet and several distinct subunits that are recognized at
other localities (e.g., the xenolithic subunit at Black Glass Canyon)
are absent from the Busted Butte section (Lipman et al., 1966). As
noted by Lipman et a1. (1966), these variations are probably due to
boththeprogressivedmangeinflmecompositimoftheeruptedmagmaand
the mechanical processes of eruption and emplacement.

In this study, an attempt was made to evaluate the vertical and
lateral compositional variations within the Topopah Spring Member by
sampling sections that were widely separated and that spanned the
entire range in thickness. However, for reasons discussed in the
following section, chemical analyses were performed primarily on

samples from the upper and lower margins of measured sections.

METHODS

a e 'o

Because precise reconstruction of thermo-chemical gradients
inferred to be present within the magma chamber is crucial to the
evaluation of differentiation mechanisms, two primary considerations
guided the sampling scheme in this study. First and foremost was the
desire to sample individual glassy pumice fragments, based on the
assumption that these samples most closely preserve the composition of
the magma, with the exception that volatiles have been lost. In
contrast, whole-rock tuff samples represent composite mixtures that are
subject to sorting and xenolithic contamination during eruption,
transportation, and deposition. Although glassy samples were preferred
over samples which have undergone vapor phase crystallization and
devitrification, it has been shown that even glassy samples have
usually been chemically modified as a result of secondary ground water
hydration and no longer strictly represent the composition of magmatic
liquids (Aramaki and Lipman, 1965; Lipman, 1965; Noble, 1965: 1967).
Second was the desire to obtain samples from sections where the entire
eruptive sequence was preserved and close stratigraphic control could
be maintained, so that the relative position of samples in the magma
chamber could be more readily inferred. This consideration was based
on the assumption that the compositional zonation of magma within the
source diamber is preserved in inverted sequence in the ash-flow sheet.

It is usually difficult to satisfy the above criteria within the
same measured section. The nature of the densely welded devitrified

interior of thick sections precludes obtaining glassy pumice samples

12

13

from the central portion of the eruptive sequence in sections where the
entire sequence is present. Glassy pumice fragments are generally
confined to the nonwelded to partly welded margins and densely welded
vitrophyres. The abundance and size of the pumice fragments also vary
vertically in the section (Lipman et al., 1966); however, this is
partly due to the effects of welding and devitrification which often
obscure the compacted pumice lenses. Although pumice fragments are
readily distinguishable in vitrophyres, their compacted nature makes
removal quite tedious and sometimes futile.

In the theoretical, ideal case, where a given stratigraphic horizon
of the ash-flow sheet corresponds to a single stratigraphic level in
the magma chamber, the thermo-chemical gradients in the pre-eruptive
magma may be reconstructed by randomly sampling individual pumice
fragments, vertically throughout the eruptive sequence. However, in
the Topopah Spring Member, it is evident that more than one type of
pumice is present within a small volume of tuff at any given
stratigraphic horizon. The variability among pumice types is readily
distinguishable by textural characteristics, most notably those of
color, phenocryst content, and vesicular structure. At the base of the
ash-flow sheet, at least five distinct pumice types can be recognized

2 and several other pumice fragments with

within an area of 200 cm
textural characteristics intermediate to these occur within close
proximity. None of the pumice fragments observed show distinct
compositimal banding or display other macroscopic features indicative
of commingling. With increasing stratigraphic height, fewer distinct
pumice types are recognizable, as welding tends to obscure the primary

textural features. However, individual pumice fragments clearly

14
display a differential response to welding that, in some cases, appears
to be independent of size or orientation. At the top of the ash-flow
sheet, the number of pumice types is similar to that at the base,
although the nature of the textural distinctions are more clearly
attributable to differences in phenocryst abundance and vesicularity,
as well as color.

This pumice heterogeneity has important implications that
necessarily influenced the sampling strategy. On the basis of
megascopic textural differences among pumice fragments, without
addition of chemical and mineralogical data, it is only possible to
conclude that the various pumice types have had different histories.
Because these differences may or may not correspond to compositional
differences (primary or secondary), discussion of hypotheses for the
origin of the pumice heterogeneity is deferred‘until the chemical
analyses of the individual pumice samples have been presented. In
order to evaluate the heterogeneity among pumice samples, each pumice
type must be considered separately. Therefore, each section was
measured at vertical intervals of 1.5 m, beginning at clearly defined
contacts with underlying ash-fall material. At each sampled interval,
all in situ, macroscopically distinct pumice types were collected, in
addition to a large block of whole-rock tuff that contained the various
pumice types. For reasons previously noted, the preponderance of
individual glassy pumice samples selected for analyses were collected
within 3 m of the upper and lower margins of the ash-flow sheet.
Several glassy fiamme and whole-rock tuff samples were also analyzed in
order to achieve some degree of continuity throughout the eruptive

sequence and to compare the compositions of individual pumice samples

15
with their whole-rocktuff composite mixtures. Every effort was made to
perform all analyses on single pumice fragments. In some cases, this
was not possible because there was insufficient mass from the small
sized pumice fragments to perform ICP, INAA, and heavy mineral
separation on a single pumice fragment. However, it is possible to
distinguish the various pumice types by textural features such as
structure of vesicles, glass color, and phenocryst content. Only
pumice fragments that were texturally identical were combined.
Eighteen of the 50 pumice samples represent composites of texturally
identical pumice fragments and these samples are indicated in the data
tables. The data base comprises samples collected from outcrops at the
Busted Butte, 311 Wash, and Lathrop Wells sections, and from drill hole
USW-GU3, the locations of which are shown in Figure l. The
stratigraphic positions of individual samples and their relation to
zones of bulk composition, crystallization, and welding are illustrated

in Figure 2.

Analytical grocedure
Fifty whole pumice and 22 whole-rock tuff samples were analyzed in

this study. After coarse crushing, the fine fraction was examined
petrographically for secondary carbonate, and if calcite was observed,
the samples were leached in a mixture of sodium acetate and glacial
acetic acid. The samples were then pulverized by hand in an agate
mortar. All samples were analyzed by instrumental neutron activation
analysis (INAA) at Lawrence Livermore National Laboratory and by
inductively coupled plasma emission spectroscopy (ICP) at Barringer

Magenta, LTD. Results of analyses of U.S.G.S. standards BCR-l and

16
GSP-l, which were analyzed as unknowns, are reported alongside their
published values in Table 1.

There was sufficient material from 52 samples to concentrate
phenocrysts for microprobe analysis. Heavy minerals from the -60+14O
sieve size fractim were separated in bromoform and mounted in epoxy.
Analyses of Fe-Ti oxide and silicate phenocrysts from selected pumice
samples were collected using a JEOL 733 automated electron microp robe
at Lawrence Livermore National Laboratory. Oxide and silicate
standards were used for quantitative analysis with the Bence-Albee

correction procedure (Bence and Albee, 1968).

17

TABIE 1. Precision and Accuracy of Chemical Analyses.
U.S.G.S. standards analyzed as unknowns compared with
published concentratiors (Abbey, 1978).

A. Oacentrations of U.S.G.S. standard GSP-l determined
by irriuctivly coupled plasna missim spectroscopy (ICP) .

(Wt. %) Albey (1978) TOP % differane
SiO 67.31 67.7 -0.58
A12 3 15.19 15.2 —0.07
F203 (T) 4 . 33 4 . 23 2 . 31
Ca 2.02 2.05 -1.49
MgO 0.96 1.07 -ll.46
T102 0.66 0.59 10.61
MID 0.04 0.04 0.00
Na 0 2.80 2.96 -5.71
K25 5.53 5.06 3.50
9205 0.23 0.35 —25.00
(PPR)

Be 1.5 1.1 26.67
V 49 51 -4.08
Ni 9 10 -11.11
Cu 35 33 5.71
Zn 98 107 -9.18
Sr 230 247 -7.39
Ba 1300 1220 6.15
Pb 53 50 5.66

B. Oaxcentratims of U.S.G.S. starriard BCR-l determined
by instrunental neutron activaticn analysis (INAA) .

23

(ppn) Abbey (1978) INAA % difference % stand. dev.
SC 34 34 0.00 4.24
Cr 16 17 -6.25 6.84
CO 37 39 -5.41 4.18
Rb 47 54 -14.89 5.93
Zr 185 169 8.65 14.60
Sb 0.6 0.7 -16.67 6.78
Cs 0.95 0.98 -3.16 7.21
La 25 27 -8.00 3.54
Ce 54 54 0.00 6.59
Nd 29 27 6.90 12.85
Sn 6.6 6.4 3.03 6.77
DJ 1.9 2.0 -5.26 3.19
'11) 1.0 1.0 0.00 6.63
Yb 3.8 3.6 5.26 9.14
In 0.6 0.5 16.67 8.23
Hf 4.5 * 5.4 -20.00 5.55
Ta 0.88 0.78 11.36 6.09
'Ih 6.0 5.7 5.00 6.99
U 1.8 1.9 -4.56 22.30

1"Flanagan (1969) .

qqqqmqqqqe-qqqqmqqqq

18

Table 2. menial Analyses of Whole Rmiess and Whole-rock Tuffs.
Sanple No. 1 2 3 4 5 6
Field.NO. EB9-IWR BBS-lAfi BBS-13* EBQ-lC* BBS-5C? BBS-10A*
211.3
$10 70.5 75.9 69.6 70.7 69.2 76.2
A1233 13.8 12.6 15.9 15.7 15.8 12.2
2:303 1.60 1.48 2.12 1.99 2.20 0.90

4.07 0.10 0.56 0.50 1.27 0.65
1490 0.31 0.07 0.40 0.42 0.42 0.12
T102 0.30 0.10 0.47 0.44 0.47 0.11
MhO 0.08 0.05 0.13 0.11 0.09 0.02
Na.0 3.28 3.47 4.09 4.03 4.43 3.35
Kéa 5.98 6.22 6.52 6.01 5.91 6.42
P205 0.09 0.02 0.13 0.11 0.13 0.03
@
Be 2.2 1.9 2.7 3.1 1.8 2.4
SC 5 2 7 7 7 3
‘V 11 10 17 16 13 3
Cr - - 3 - 4 -
CO 0.4 0.1 0.5 0.6 0.5 0.2
Ni <1 <1 <1 <1 2 <1
cu 5 10 3 4 4 4
Zn 78 19 121 124 82 31
Rb 154 171 148 151 138 175
Sr 116 15 179 149 203 28
Zr 391 138 699 603 732 143
Sb 0.3 0.4 0.4 0.3 0.1 0.3
CS 3.96 4.61 3.14 3.39 2.62 4.02
Ba 1390 117 2910 2230 2350 160
La 113 31 200 185 217 48
CE 170 70 320 321 360 101
Nd 61 31 104 93 100 37
Sm 9.2 5.8 12.5 11.8 13.2 6.3
Eu 1.6 0.2 3.2 2.7 3.6 0.4
'11: 0.8 0.7 0.9 0.9 0.9 0.8
Yb 2.8 3.1 3.2 3.3 3.1 2.9
Du 0.6 0.6 0.5 0.5 0.5 0.6
Hf 8.8 5.0 14.9 11.9 14.9 5.8
Ta 0.98 1.35 0.77 0.87 0.80 1.29
Pb 30 25 40 40 15 5
'13) 19.7 22.7 19.9 18.9 20.3 25.1
'U 4.6 4.7 2.9 5.0 2.8 5.0

I-

Major element oxides have been recalculated to 100% anhydrous.
locations of sanples (see Figs. 1 & 2) indicated by two letter prefix:
BB = Busted Butte; Cp=311Wash; IW=IathropWells: GU=Drill Hole
USW-GJB. "WR" suffix in field no. indicates whole-rock tuff. An
asterisk indicates a carbined sanple of texturally identical pumices .
All other sanples are of individual whole pumice.

11

10

--25WR BBS-320M? BBS-ZOOWR BBS-100WR

Table 2 (cont'd.) .

8

.7

Field NO. BB9-10C* BBQ-159R

Sanple No.

05796882
7305000910

62100nw0350
7

33591431
2396 01960

coco-coco.
GROOOOOBSO
7

689%wm6 9m

5n”.0.0.AU.0.nm4..50

sznwanmw

eeeeeeoeoe
“ED—1.000450

69%nwnmwmn

eooeeoeeoo
“321000460

4.34.9095
7.nU.34w4..4..14..7.

mmzlmmmdu’mnu.

% 2 5
mmssmmm 4s

6 8
2 48 7272473 08
O .0 0...... O.
03442200304945002041513
3 4026 5 62 22
2 1
4 8
2 44 238.3613 8.0.
O O. .0.
0133076040536&0.nm3051035
< 4B2D 8382 42
8 l
2 37 7.38.1593 15
O .0
077702103242750.0.30.4..1524..
4825 9372
1 1
2 2
7 29 2990609 25
O I. 0...... O.
045$319010147H2030B0504
3 D63 8819 22
16 313
1
a 4
6 l £4..90.64..8. 6.1
O .0
064367602019413m3nw4..0.092
l 6n05 20411
26 4231
2
9 0
6 27 0798548. 54..
O O. 00....
0876545020 2 302040.093
9 1.0.27 432mm 111
1 26 $231

mssvsmmmmmsusssmmmmmmmmmnmmu

18

BBB-IOWR

17

BBS-158 BBB-15C

16

20

15

Table 2 (cont’d.) .
BBB-20

13 14
Field NO. BBB-85m BBB-853*

Sanple No.

44. 17463
9596 10060

7u00000340
7

07333
2295u.10.26nu.

8m.nU.0.0.0.nw34..nm
7

O
7““.nW0.0.0.nU.24..nm
7

mu.0.m0.0.0.34u0.

99mwmnmwm

0.0.0.0...
6u00000340
7

877079u3
4.0960104. 0

00.00.0000
6n00000440
7

O 0
4 41 1278493 32
6140558465002041515
824 2252 22
1 l <
5 6
3 31 527.J593 JJ
7710573685nmnm30.4..1535
81B 2362
l
3 7
8 45 7.37.J54..5 33
I O.
394670596365nmnwlnm&157.5
15317 4382
l
9 7
2 33 4..2.7.n~54..3 55
O O.
05

749650.0.3AU.51524..
2372

4 2
l 4.1 2394605 41
o O. 0...... O.
0 . 005500021857003061056

25334. 13483 22
2 l l

7 2
2 33 $27.0.483 82
01353970128195nmnw3nm4u100.4..

< 4N3...“ 14372

mssvsawmmmsussmmsmmmnmmmmmmu

21

Table 2 (cont’d.) .

24
BBS-1

23
BB8-2

22

BBB-3A BBB-38

21

20

19
BBB-5

Field NO. BBB-10

Sanple No.

36416 21 4
3384110700 8 2 32 J56.547.5 36.
8u00000250 2211066185605707550.nw2nm4L00.4
369 3 2352
1 1
697mm152 7 1
54555 98.0. 9 2 40 4..57.J555 6.8.
LRO.0.0.0.0.L4..& 2211060785005716650.nwL0.4..L0L4
448 D 2362
1
4647 102 5
5554..JJ%550. 8 2 30 0.55J5J4.. 55
O O O.
LELLLLLZSO. 22220621647065522 .mnmnwLO.7.L54..5
26120 2493 12
2 2 <
760 732 9 7
05841 800 8 3 38 2278543 88
0.00.00... 0 O O. 0...... O.
8n00000250 22110651 00551545002051014
7 6 2362 32
1 <
375®7602 9 1
38840 0.7.6.0. 8 2 70 528.5555 0.5
0.... O O O.
9u000nw0.24..nw 2212066075805752950.nwan4..L525
7 48 0 2382
l 1
651 714 1 6
819832089 8 9 4.5 557.5555 57.
00.0.00... 0 O I
6D00000240 222206D920fi05.73 6550.0.2.0.5.L024..
7 4331 23 62

mmuzewmmm em. a:vsmmmmmsusgimmmmmmmmmmu

30

28 29
CP3-1WR CP3-1A CPB-lB CPB-lC

22
27

Table 2 (cont'd.) .

26

25

Field NO. CP3-2A CPS-28

Sanple No.

79416493
8694“110.34..nw

6u.anmnwnmnm35nw

487 3132
128Ah~®nw1nwnw

0010.0.0.0.nw350.

A55Ammmmnum0.

8Hwo.nwnmnwnm3.50.
7

9085 497
36693....”960

szmmmmLim
71

emunwmman1

nmm2nm0.nw0.360.

7218
702074

0.00.00...
0521000350
7

mnemmfim 8%

9 4
8 3 43 83.].nw513 55
0 0 0.
2335098944705596850.0.30.51534
4814 2372
1 1 <
8 3
7 6 47 12—I.—I.57.3 0.6
. 0 .0
221108..”05450471%550.nu.20.4..100.4..
4 471m 23
1
3 5
8 2 41 53—].9563 21
0 0 0.
48 2372
1 1 <
2
0 5 2 7990610 16
0 0 0. 0...... .0
.458408763130347379103001513
5466 7337 1 22
1 4 512
0 4
7 8 62 4..-[.386nw8 89m
0 0 .0
17u50u50131044853 .Imo..ImAU.30.5nU.7m
9452 $020 1 72
31 6 .431 5
8 8
6 7 21 2892787 03

usevsmmmmmsussmmsmmmmmmmhmmu

36

34 35
CPI-2E

23
33

Table 2 (oortt'd.) .

32

31

Field NO. CP3-1D CP4-20WR CP4-6CMR CPI-BWR CPl-BA

Sanple No.

400077
3A85110.3mnw

7.”.nU.0.0.0.0.34..0.

498 731.4
3834.... nU.4..70.

nmmmmmmfiqdunm

sznwnmmuwm

o o o o o o o o o 0
3410000440
71

1.71.7 4.45
30.88am?” A30.

1.51.0.nW0.0.4..5nw
7

461.8
0.3.].853W5

nmlmnmmnm360.

0. 2
30
41
166
35
220
0. O
2 .81
152
70

136
39

4.42

0.3
252

157
7
51
164
46
305
0 . 3
111
213
67

3.50

O . 6
17
8
52
145
43
431

O . 2
314
163
278

5
4..3—/.260.4.. 73

35nU.nU.30.51.0..uw4..

7
6.27.7.583 7.9

.45.U.nU..Imnm4..1.on4..

8
83836.44 59

0.... O. .
05003051044.
3 32

8
6J884h81. 7”?”

60.nu..40.61.0nu.1.

1.
8A8.1m7.21. nU.8

Onlo.3o.Qn1.534..

4
~I.1.Qunw660. 6.0.

OanmO.3nan.1.O1../m
91.

1..

.3“...
mufimmmwwpu aivgm mmmagimammmnmmmnmmu

42

I.W2-5

41

4O
IWZ-A

24

39

Table 2 (cm1t’d.) .

37 38
Field No. CPl-lG CPl-AFB CIPl-AI‘WR Im-A

Sanple No.

.00. 0..
0510000460
7

6483055
618234....92
6

«filmmllnwnmnw3

0.10

226u7432
64950 0390

......o...
7u00000340
7

5694..n.1...%9m.0.

«H Amnwnmmnw25nm

19%,..mmm7.mm1

nummnmnmo.35nu.

n”.020 5
aumwmmm 4%

0 0
222206516u
5n

9.211065%

8
4.280.380. 0../.

89an3nm91513
6 1.2

839850.9 83

1.38859m4 9.8
1.1.60.nw.lmnw51.533
93

7
0.384664 37
4076003051045
38.4 2.4

1.
6.2.an50.4 4.9.

”6 .5.nU.0.3nU.51.534..

mmxvammmmmauamauammmmmmmnmmu

48
1W4-SB

47

W4 -5A*

46

25

45

Table 2 (corrt’d.) .
1W4-1A IBM-18* 1W4-1C

44

43
Field No. IN2-10

Sanple No.

5599 5.21.
396533 781.

0.0000000.
elm-11.000360
7

6 795684
268 000210

cocooooooo
8n00000350
7

coo-......
0521000360
7

477787
193D../m./w0.1~30.

3...“.110.0.0.36.U.

60.94..n.nm%9

7.n.nm0.nmnm0.350.
7

206 5443
7.4..851wnw110.

8um0.0.0.nw350.

m5“... 2 5
mmmgmmm 9W

7 7

7 3180.638 .I.5
0

.2

nw.2nU.3nw1.nm.592
1. 121

9 4

1.. nw2.l.0”563 0.9
0

5

53166nw0..lm0.4..1024
.2362

0
m 0081.641. 90
4 08103081004
5 22

3 9

8 .I.4...I.Q~50~.Im .I.1.
0

4

wsmmznm41515

6 5
0 3.279463 02
5

006:.nm0.9.nw4..1.59.=.
362 32

m2xvammmmmauaammmmmmnmmmnmmu

52 53 54

26

51

Table 2 (cont’d.) .

50

49

Field No. 1W4-10A IN4-10B LW4-15A IW4-158 IN4-15C (113-31M

Sanple No.

11938474
9646120530
4310000440
71

1563978
1nw0.5440.56
5

0.5.b10.0.0.4..

0.14

13 0 445
8680” 3.20

000
nmmmmmm350

sommnwmuwm

7n0.2nu.0.nw34unu.

965%3 3w3 um

0.4..11nw0.0.4..6.0.

301 :n
1684..3 nu...nw
num1mnw0350

3%; 5
fi mammm am

I

5
7 3 7 25968.].3 84.
154.013%577035 01.910.30.91557m
< 984 0097
1 4 811
3 8
6 7 27 3391587 48
0 0 .0 0000000 00
16920884339020611 303030582
17u05 9991 1 21
26 6121
2
3 0
7 4 49 33-I.15nw3 0.9”
0 0 0.
2.2.2308991030457435nwnw3nw515”w5
3835 237.2
1 <
9 5
5 5 47 82.].8552 8.].
0 0 00
223304403m00458634nm0../m0.4..100.4..
2146 n .2252
1 <
7 4
8 6 30 383nw539 4.1
158 . 083a667034870nw10.30.1nu.00.3
.2 ”88 13481
4 21.2
3 6
5 4 46 saga/.8537” 66
0 0 00
233408062750403215nU.0..Imo.515nm4..

mamvamMmmmaumammammmmmmmmmmu

60

58 59

27

57

Table 2 (cont’d.) .

56

55

Field No. («113-31AM? GJ3-29WR CUB-289R GU3-23WR (113-21m GUB-ZOWR

Sanple No.

29316711
4..0.nU.4..11n~nw—I.0
m 10.nw0.nw430

30470687
anw87331u-J80

duo

lfilmmmmdu

7548 096
80.57.9mJM66O

I...
Lulmnwnw044o
7

.lenmnwmmduduo.
7

1492 645
074812 220

coco-o0...
6210000440
7

4 2
1 37 14..—I.2324.. ~I.—I.
012629w03023660.nw20.4”1023
< 4.05111 5483
0 5
4 44 nw384h539 33
O O. 0.
01325 1042778 2nw3nm nw023
4138
2 mm
3 07 8580w65 63
O .0
4 311
3 9
3 36 5288572 86
O .0 0...... .0
0129n170323447102081003
< 5 75 8974 52
1 3 7 1
6 5
3 36 7489661 81
O .0 0...... O.
02323990578$18102081013
4773 49 6 32
1 3 6 1
3
4 5 2703014 03
O O. 0...... O.
01392830374931114111583
< 5376 9n381 1 42
3 6 2

O 5
my agmzmw‘m‘mz at?immmmauifimmmmmmmmmmmu

66

Gmat

65

(113-10*

28
63 64
(«113-11*

Table 2 (ca1t'd.) .

62

61

Field No. GUB-l7WR GUB-14VR GU3-12

Sanple No.

25696821
SAHnNSOOO—ISO
o

5n10.00035

157 7201
11350. 0650

0....
6B.0.00.00350
7

...flmmMflwm
fiDOOOOOaJSO

516 0111
67950 1550

0.00.00...
6u00000350
7

m8105543
92 4.110290

0.0.000...
8u10000420
7

9394nmmnmm

8D.O.nW0.nm0.33O
7

20 20 5
”memmm 9w

7
2 41 23£A£AS n~3
01202310779105nw0.30.5L5,m4
< 5328 6283 22
2 1
6 5
2 36 0.27.3353 55
O .0
060772005290.5nw0.30.4..L0L3
115320 427
1
fl 2
2 4 4..27.n~54..3 34..
O O.
015657605508 450.nm20.4..L524..
< 5 14 332 22
2 1
8 5
2 74 327.9,mfi3 7.5
o O.
013570205m056 5mm20.4L0L4..
< 512R 36
2 1
0 6
2 44 7378523 34
O O. .00.... O.
05407870408055002051034
5816 3373 22
1 1
7 3
2 42 5369514 14
0 O. 0...... O.
01261830422234002051034
< 4m1u 3372 22

maxvmmmmmmauamamammmmmmmmmmu

72

CUB-1*

29
70 71
CUB-5* GUB-2*

69

Table 2 (oont'd.) .
Gin-6*

68

67
Field.Nb. GU3-8* CUB-7*

Sample No.

. 0099 271
330700 04.0

0.0.0.0...
6D10000440
7

380$o mo 9mo

6&10.0.0.0.350.

fiAQSMMWJMmm

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739mo mmmmm

6D.0.nU.O.nU.nU.34..O.

83%w nu7 52

5D.nU.flwnU.0.nm35nm

002
4..1nU.5®.115 O.

6.B.10.0.0.nw350.
7

0
l 2 55 4..2an553 13
321201674570628695nwnm30.4..1525
1.. 6834 4364
1.. 1 2
7 8
9 5 1 45 27w7.Aw213 4..8
0 O O .0
23< . 03136160571295nm0.2nm4..10nw3
4D2D 4372
4 0
8 0 52 5nwnw7.0.nw0. nwl
223.01.. “31.06016.50.0.20.0.nw525
< 03 935
2
a 0
9 2 3 12£w520.1 0.4w
0 O O.
222 . 01213270502$35nwnm7mnm415mmdu
< 562E 63
1
7 5
2 2 3O 326.].539m 7.8
3231013W2470522104..0.nm20.4..10nm4
< 84.4 4373
1 1
9 0
1 2 58 93974.96 11
O O O. .000... O.
333 . 015W1410723965003051565
< N3“... 4.373 22

03 o
wflgwmmmwm‘w. mivammmmmagimmmmmnmmmgmu

RESULTS

Major Element Chemistry

The major element oxide analyses are reported in Table 2. For
purposes of discussion and graphical presentation, all values have been
recalculated to 100 weight percent excluding loss on ignition (LOI) , to
facilitate comparison between variably hydrated glassy and devitrified
samples. The overall range and trend in major element composition of
the Topopah Spring Member was first reported by Lipman at al. (1966),
based on 13 whole-rock tuff samples and one densely welded crystallized
pumice sample. The additional analyses reported in this study are
consistent with those provided by Lipman et al. (1966), and also help
to clarify the previously addressed question regarding an apparent
compositional gap. More important, these additional analyses
demonstrate that the textural heterogeneity of pumice samples observed
in the field corresponds to chemical heterogeneities among the pumice
samples, with a systematic variation in their compositional range with
stratigraphic position in the ash-flow sheet.

Figure 3 illustrates the variation of the major elements with
stratigraphic height in the ash-flow sheet at each sample location.
Considering only the whole-rock tuff samples from the Busted Butte
section (Figure 3a), 8102 displays a total variation from 77.9 wt. %
near the base to 68.5 wt. % near the top, with a pronounced chemical
change to lower values of $102 coincident with the transition from
crystal-poor tuff to crystal-rich caprock (Lipman et al., 1966).
However, the various pumice samples occurring at a given stratigraphic

level display a range in Sioz. At the base of the ash-flow sheet,

30

31

 

 

 

 

 

 

 

 

 

 

m:f s , an Q Long PM man up w;- :D'q, F
- ¥ b L p
: E t L f ’
j”. > L > L
.5. L ’
O + ’ ’ ’ '
2100+ a > a *o ’u n a ’o *9
L . . . . . .
r . . p h b >
a Lu *0 ’0 *c a ’0 Le: >
a? p r h L b » ,
L 3 L9. La .9. t t L9. la: ;
L
(a! 0 Lu— LL— Lc:_ I—‘I— .4— {—5—

007270” 11131517012 3 0 1 2 3 00.31.000.51.000.1023 4 0 3 5 7 00.102

 

 

 

8102 A120: «.203 m one no no2 Mao mac K20 9205
' o c , a a 3,, 1' -.: -. : : :
no E * - t I 'r E ',
...: t E ' E L t
- ‘ . k r _L L L
5 L I L E E i I
‘- 100 L ’ 1* .L k r
2 * L : * t i r r
t » t r ir F L
100 k L r ‘
. L L , .t F
I r ; L f r
,0 . L L [ t
‘ ....L...._.....L___._L_
n» ’ r t

007270” 11131817012 3 0 1 2 3 00.51 00.51.000.1022 4 3 5 7 00.102
8102 M203 30203 (1’) one "00 7102 “no '4on K O P

0* r“. . f. [a [A “ .u'
L f t : i L L
A l .L L .L
o o 2

007270” 111315170 1 2 3 0

”ML...

 

 

N
a
O
o
b

 

 

 

 

 

m '
3102 A1203 “203 (1’) co Moo T102 Mao NezO K20 P208
m . I r on ’ I r o r [I - e r I 9 L.
L o i o . o c t . c ; : F : a t. c
2”? o : o : o :1 " z t a : :1 L: a c F 3
: o : o i o c ‘a {c : : t : t :1 E
L p t - y. L 5
2m ’ r > - r F L
‘- ’ U ' O t 3 O '0 PO 3 t 3 r 2 f
s L : p £ : P t E L
i ""I _ ; I : ' it i
b y. L r ' t I?
P L c. \- n n 2
‘m I a , a It a [. “:1 __. .. :1 L... f":3
. i C r i I' :
..E ’ t ‘ ' . : :
> e C u .. I I. i T. I .0 - I . e I
n I L o . e e e - a . a 1: a I
(d) o Lt L ".1: 'I L 13.. '_e_ _._a_ i...
007270N11131017012 301230051005100102240 35 700.102
3102 A1203 F0203 (1’1 cao M00 7102 Mac “-20 K20 P205

Figure 3. Variation of major element oxides with stratigraphic
height. Analytical data from Table 2. Solid symbols = whole pumice;
open symbols = whole-rock tuff. (A) Busted Butte: (B) 311 wash:
(C) Lathrop Wells; (D) USW-GUB.

32

all the pumice fragments are high-silica rhyolites, and although
individual pumice samples have marked textural variations, they display
only a modest range in 5102 content. In contrast, the range in
Sioz for pumice samples at the top of the ash-flow sheet is nearly as
great as that of the entire section. At this stratigraphic level,
there is a compositional variation among pumice samples ranging from
high-silica rhyolite to quartz latite (76.2-67.7 wt%). Although no
attempt was made to quantify the proportions of the different pumice
types at a given stratigraphic level, comparison of the compositions of
the various pumice samples with their associated whole-rock tuff
composites gives a first approximation of their relative abundances.
It must be noted, however, that while sufficiently large whole-rock
tuff samples were taken and their lithic fragments removed before
powdering, only one whole-rock tuff sample was taken at a given
stratigraphic level.

Unfortunately, due to the difficulty of removing pumice fragments
from the densely welded central portion of the ash-flow sheet, it was
not possible to fully evaluate the degree of chemical heterogeneity at
every stratigraphic level within the entire eruptive sequence.
Although the textural variations of pumice lenses in the densely welded
devitrified horizons are less extreme, careful observations allow
subtle distinctions among pumice fragments to be made at most
suatigraphic levels. Based on data from other pumice samples and the
overall chemical similarity of whole-rock tuff samples within the
crystal-poor rhyolite, any compositional differences corresponding to

these textural differences are likely to be modest as well.

33

The relationship described for Sioz at the Busted Butte section
has corresponding variations for all the major oxides and at all sample
localities. Figure 3 clearly shows that the chemical compositions of
individual pumice samples within a given stratigraphic level are not
unique, but display a range in composition. Moreover, pumice samples
with compositions similar to those deposited during the early phase of
the eruption are present throughout the eruptive sequence. The range
in pumice compositions increases with increasing stratigraphic height:
however, due to the paucity of pumice analyses from the central portion
of the ash-flow sheet, the progressive nature of this increase in range
is uncertain. This chemical heterogeneity has profound implications
for the reconstruction of inferred chemical gradients in the magma
chamber based on ash-flow stratigraphy.

The interelement variation of the major oxides with weight percent
silica is depicted in Figure 4. The solid symbols represent analyses
of pumice samples whereas the open symbols represent whole-rock tuff
samples. The overall trends are consistent with the data reported by
Lipman et al. (1966). In these previously published analyses (diamond
shaped symbols), no data points occur in the interval from 71.8 to
74.7% $102. This apparent gap was thought to be real (Hildreth,
1981) and has been interpreted to indicate the existence of a sharp
compositional interface or a narrow transition zone within the magma
chamber. The additional analyses reported in this study show an
overall continuity in the variation of 3102 , although compositions in
this aforementioned interval are significantly under represented. The
paucity of compositions in this interval may be due to inadequate

sampling of the central portion of the eruptive sequence, because three

34

 

 

 

17’ 1.0L
9" "
n 15" ... Q5 .
ON - -
3 13» 0
11r- 0'2;
J J o
s L-
3 E 0.1.

 

 

 

“203 (T1
to

, I
t (‘5
’- D

19

3

ea c

 

 

 

 

 

 

 

 

 

1 . O
m 4‘ 4
2
o n l 1 ;l L J
3. 2
~ 7
2- a L
9 r- .Dfi... . ON 5?
o 1L 37-0 L . . x P
L 0 «Fame. 3,
o ._J._l l l L l 2. I l L J
10L- o‘::.2£ -
" I
a .-
g. .. roll
066 66 70 72 74 76 066 66 70 72 74 76 76 60
850 $50

2 2

Figure 4. Variation of major element oxides vs. silica. Units in
weight percent. Solid symbols = whole pumice; open symbols =
whole-rock tuff. Source of analytical data: squares from table 2:
diamonds from Lipman et al., (1966).

35
of the six samples that occur in this interval are from the interior of
the sequence. Alternatively, it may be that the occurrence of
compositions in this interval is the result of limited mixing between
compositionally contrasting magmas.

This latter view is supported by several lines of evidence. Four
of the six samples in this interval are whole-rock tuff samples that
contain more than one pumice type, and therefore do not represent the
composition of a single parcel of magmatic liquid. The two pumice
samples in this compositional interval were collected from the very top
of the distal portion of the ash-flow sheet and occur alongside both
more silicic and more mafic pumice samples, and thus their relative
position in the magma chamber is uncertain; they may represent either
mixed liquids or fractionates resulting from differentiation processes
occurring near a compositional interface. In spite of the absence of a
distinct compositional gap, the hypothesis of the existence of a sharp
magmatic interface or a narrow transition zone is consistent with the
interelement variation trends. From Figure 4, it is apparent that some
of the major oxide trends are not strictly linear, but display a
dichotomous distribution with a change in abundance occurring within
the interval of the previously noted gap at approximately 74% $102.
This is best illustrated by the oxides Fe203(T), and Tioz. The
more abundant high-silica rhyolites (>753; SiOZ) do appear to define
linear trends, generally having little scatter and showing very slight
variation of the corresponding major elements with increasing 5102;
this latter feature may be an artifact of the constant sum effect.
Notable exceptions are the alkalies which may be mobilized during

secondary hydration (Aramaki and Lipman, 1965; Lipman, 1965; Noble,

36
1965; 1967). Although there is a greater density of data points in the
high-silica group, these analyses represent an equal number of samples
from the upper and lower horizons of the ash-flow sheet.
These trends can be interpreted to indicate that high-silica
rhyolitic magma was separated from underlying low-silica rhyolitic
magma by a distinct compositional interface within a single magma body,

and that two compositionally distinct magmas evolved concomitantly.

ace eme t

Highly charged trace elements, particularly the rare earth elements
(REE), are especially useful in evaluating petrogenetic models because
they often display relatively large variations in abundance within
coeval rocks that have only a modest range in major element
composition. In the Topopah Spring Member, there is a strong
correlation between the abundance of certain trace elements and major
element concentrations. The chemical heterogeneity among pumice
samples that is observed with the major elements is also observed with
the trace elements. These data further support the hypothesis that a
sharp compositional interface or narrow transition zone existed between
chemically distinct magmas within a single source chamber. Trace
eluent abundances of samples analyzed in this study are presented in
Table 2.

Figure 5a illustrates the variation in the abundance of seven REE
for all samples of the Tqiopah Spring Member. The ordinate value is
the ratio of the concentration of an element in the sample to the
average concentration of that element in chondrites reported by Haskin

et al. (1968). With the exception of one whole-rock tuff sample

37

   

 

 

 

 

103- 103
3 ’ 8
E 102; "' 10’E
5 ’ E
\ \
e a _
5 10‘ 3 10‘
im - i (b)
10° 99'. . FLEET"; . 1 NM“. 10° “9°. LSTEKT". L L LYPL.“
565880626466687072 565860626466687072
Atomic number Atomic number
103;

 

(c)

 

 

we‘ve 1 we“. we"
56 58 60 62 64 66 68 70 72
Atomicnumbot

Figure 5. Chondrite—normalized REE abundances (log scale) vs. atomic

number. Solid symbols = whole pumice; open symbols = whole—rock tuff.
(A) All samples; (B) quartz latite (low-silica rhyolite);

(C) high-silica rhyolite.

38

(CP4-60WR), indicated by the dashed line, there is a lack of samples
with intermediate concentrations for the elements La, Ce, and Eu, which
allows two major groups of REE patterns to be distinguished. Within
each of the two groups, the individual patterns illustrate continuous
variation, and most patterns within each group are subparallel,
indicating an overall coherence in REE distribution. Several samples,
however, have patterns that display a cross-over near Sm, with slight
LREE depletion and corresponding HREEenrichment, similar to that
observed in the Bishop Tuff (Hildreth, 1977).

The REE patterns that lie above the trend of CP4-60WR (Figure 5b),
generally correspond to samples of low-silica rhyolite (quartz latite)
and all of these samples occur in stratigraphic units that lie above
CP4-60WR in the ash-flow sheet. Within this group, the negative Eu
anomaly progressively diminishes to predicted values,* as the LREE
concentration increases, with up to 7 times the La concentration of the
high-silica pumice samples. The REE patterns that lie below the trend
of CP4-60WR (Figure 5c) correspond to samples of high-silica rhyolite.
These exhibit relatively little variation and are characterized
by large negative Eu anomalies and maximum LREE enrichment of
approximately 140 times chmdritic abundances. In contrast to the LREE
enriched samples, pumice samples that exhibit these trends occur
throughout the ash-flow sheet. The REE patterns of individual samples
in relation to their stratigraphic positions in the ash—flow sheet are

illustrated in Figure 6.

 

The predicted Eu concentration, Eu*, is that calculated by linear
extrapolation between the diondrite normalized concentrations of S m and
Th on a plot of REE concentration versus atomic number.

103
mung
L 1
160 , 101 L 1.x
LaOe one. 11:

 

39

 

 

 

o0
unmuuuumng
Atomic number

I

 

(0)

Atomic number

  

 

 

Atomic number

10’ L
E 50 "
i
a! 0
10"
(c)
Figure 6.

whole-rock tuff.
(D) US W-GU3.

“SBNGZMOBBSNH

"OH" (1111

Height (m)

160

.
100~
D

 

 

 

LeOe sum: ‘YbLu

 

10° + A
L 505800020400007072

Atomic number

Semplelchond

     
 
  

00 L100 Sm :l'b 4 A 1va
‘mumauumnn
(b) Atomicnumber

103

10‘
10° no. man, LYbLu
505000020400007072

   
  

    

   
   

 

(11) Atomic number

Chondrite-normalized REE patterns in relation to
stratigraphic position. Solid symbols =- whole pumice; open symbols =-

(A) Busted Butte: (B) 311 Wash: (C) Lathrop Wells;

40

This systematic chemical heterogeneity among pumice samples, which
is most pronounced at the top of the ash-flow sheet, is demonstrable
for nearly all elements that have a significant range in concentration
(see Table 2). Rather than plotting all the trace elements versus
stratigraphic position, it is useful to consider the covariation of
selected trace elements for which a large variation has been
established.

In Figure 7, various trace elements are plotted against SiOZ to
illustrate their behavior with increasing differentiation. The
elements Ba, Sr, Eu, Zr, and La, all decrease with increasing SiOZ.
These trends are consistent with control by fractionation of alkali
feldspar, plagioclase, zircon, and chevkinite/perrierite, phases that
are petrographically observed in the low-silica samples. In contrast,
the elements Ta, Rb, Cs, Th, and Sb display incompatible behavior, all
increasing with $102 . A significant feature common to all elements
shown in Figure 7 is a marked change in concentration at approximately
74% 5102, similar to that observed for the major element oxides. To
illustrate that this rather abrupt change in elemental concentrations
is not solely an artifact of the non-linear behavior of Sioz, several
of these elements are plotted against each other in Figure 8. The
trends of Ta, Rb, Ba, and Hf vs. Th all display apparent inflections
for the same abundance of Th, although the changes in abundance are
less drastic for the incompatible elements Ta and Rb. Trends of
compatible vs. incompatible elements (i.e., Ba vs. Rb) or of two
elements that are compatible with different phases (i.e., Ba vs. Zr)

generally show greater changes in abundance.

41

 

 

 

 

 

 

 

 

L 0- -
315002- a g
L ' g3
L w a”
01; 1L1ID1JQ 1b
240: .0.-
.. .I
.- m .
«71 120- o
.- ‘ EEG
_ Van‘mmm
o lJJiLJ 1 LLL #4
4r-
_ emu '
_ e-
o I
13 2- ~00
_ m- g
D [DE]
. '13
P
o LLI 1 11 1 1*4
600’
I
Igfi.
. L0
(D
rt. war :1- e fin]
- a. CD
. E! a l
o i 14 1 1 1 1 1 1 LJ
240'
. owl-'I
F E] m
_ c:
' 1201-
..1 .. E] El .' 83m
_ [D
o 1 1 1 1 1 14 1 #1 141 1
as as 70 72 74 70 70 so
3102
Figure7.

Te

Rb

Cs

Th

Sb

Trace element abundances (ppm) vs. silica (wt. %).

2.0 L'
1.5 I

 

 

33 _

1.0" r1! F- %. a .

r e34
0.5

L

o 1 1 L L l 1

260-

. ...

2201' I.
...L @9311-
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140'” . I}
- @

 

 

 

 

 

 

1m 1 1 1 J 1 1 1_1 1 1 1 1 1 1
12F o
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91-
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6- é:
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3- IEI'I‘ ‘mfiw
o L LL_L l A J. 1 l l L L4]
30
CD
27 '
II.
24L- 9 m
21L - a. we?-
L'E71" 1‘ . "
18 i 1 .141 1 1 1 1 1 1
0.6
L m _ .
06 .
r - El . I
0.4L- 2 m
~ I
I I
0.2 I‘3 03.33.
L m-
o 1 1 L L 1 L 1 1 ‘ l
66 66 70 72 74 76 76 60

SK)2

Solid

symbols = whole pumice; open symbols = whole-rock tuff.

 

 

 

 

 

 

 

2F
. (.I
_ M's ‘3
a1_. 5 E]
'- a‘“ .0
o L4LLLL1 1
Th
260v
’ II
um" ”'9
’ o I
£13m as“? . a
I“ 3.0
‘.g;f'
100 L11LL1111
Th
161-.“
"I
*‘Io’.'m o
E 8- 0 “A '3 m
. 0 ' I
Paw...
0 L 111111111111111
Th
3000f...
g
1..m.
81500' 00
1- .0 0
r3 E!
L . 0 .
18 21 24 27
Th
Figurea.

Solid symbols =- whole pumice; open symbols

42

 

 

 

 

 

 

 

3000E ... ,
0. .
31500- 0 E,
* I
.. 0 d3 @
0' .ilfifi H
100 140 180 220 260
Rb
240g .
c 1“.
i- D .
a 120» a
.. - -
“b a?
- I
o- I 3%35319 4'-
100 140 180 220 200
Rb
3WDL I.' -
L . a:
81500- a a
C 005
- A”!
00 30 60 90120150180210240
3:
3000
L .r-
L- .0 I
£1500- c: o
‘ I
:y & mfl’ql
owe: L .1 ..
0 200 400 600 800
z:

Inter-element variation of selected trace elements (ppm).

whole-rock tuff.

43
Coexistm' g Iron-Titanium Qggigeg and Estimated Temperatures

In conceptual models of magma chambers, probably the least
equivocal assumption is that the temperature of magma increases with
depth in the chamber. In contrast, the assumption that the composition
ofmagmabecomamoremaficwithdepthinthediamberislargely based
on inference from the overall whole-rock compositional variation with
stratigraphic height within ash-flow sheets. Although this last
assumption is considered quite reasonable, previous sections of this
paper present clear evidence that pumice samples that most closely
represent quenched parcels of magmatic liquid, do not strictly become
more mafic with increasing stratigraphic height in the Topopah Spring
Member. Therefore, it is desired to isolate some other position
dependent parameter that can be used to constrain chemical gradients
within the magma chamber. For reasons discussed above, the quenched
equilibrium temperature of liquidus phases would appear to be a logical
choice.

In order to employ the iron-titanium oxide geothermometer and
oxybarometer of Spencer and Lindsley (1981), heavy mineral separates
from 52 samples were prepared for microprobe analyses and 50 samples
contained both magnetite and ilmenite phenocrysts. In many of these
samples, either the magnetite or ilmenite or both display visible
exsolntion lamellae. The term "exsolution" used herein refers to the
occurrence of Ilm-Hemss along (111} cubic spinel planes due to
oxidation of Usp-Mtss, and the occurrence of Usp-Mtss along (0001}

rhombohedzal planes due to reduction of Ilm-Hems These processes

5'
of oxidation (and reduction) generally take place at temperatures above

600°C (Haggerty, 1976, p. 18). As pointed out by Buddington and

44
Lindsley (1964), this is not true exsolution in the classic sense but
has been aquted for lack of a better term. Some grains also display
oxidation to maghemite and hematite along grain margins and fractures,
possibly due to ground water movement through the ash-flow sheet
(Lipman, 1971). These grains were not considered for analyses.

Previous workers tried to minimize problems of subsolidus oxidation
and unmixing during devitrificatim by studying Fe-Ti oxide phenocrysts
only from glassy rocks (Carmichael, 1967: Lipman, 1971; Hildreth,
1977). Hildreth (1977) suggested that the exsolved oxide phenocrysts
in the Bishop Tuff possibly resulted from protracted cooling in fully
crystalline welded zones or were due to emplacement over wet ground of
the nonwelded basal portions. However, even when only glassy rocks
were considered (i. e., when nonwelded basal pumice samples were
compared with densely welded vitrophyre), Lipman (1971) noted that
there seemed to be little correlation between degree of oxidation of
magnetite phenocrysts and cooling history.

Although post-emplacement processes were no doubt werative to some
extent in the Topopah Spring Member (Lipman, 1971), the following
evidence is used to suggest that exsolution may have resulted from
dynamic processes occurring within the magma chamber prior to or
concomitant with eruption: ( 1) several individual pumice fragments
contain both unexsolved and exsolved oxide phenocrysts; (2) entirely
vitric pumice fragments from the nonwelded top and base of the
ash-flow, which may have been emplaced over wet ground but were
certainly not subjected to slow cooling, contain both unexsolved and
exsolved oxide phenocrysts: (3) samples from the central fully

crystalline (devitrified) welded zone, where protracted cooling is

45

unequivocal, contain both unexsolved and exsolved oxide phenocrysts.
Any secondary alteration process, occurring outside the magma chamber
and operating on a local scale (pumice fragment or handsample), should
effect all oxide phenocrysts of the same composition more or less
equally. If any such process is argued to be compositionally
selective, then the presence of variably effected phenocrysts is strong
evidence for primary compositional differences. Although the
possibility of xenocrystic contamination during emplacement must be
considered for whole-rock tuff samples, this problem is avoided for
individual pumice samples (Lipman, 1971).

Therefore, the exsolved Fe-Ti oxide phenocrysts in the Topopah
Spring Member are interpreted to reflect disequilibrium within the
magma chamber. Because the compositions of Fe-Ti oxides are extremely
sensitive to changes in temperature and oxygen fugacity of the
surrounding silicate liquid, if the thermal regime is perturbed, the
composition of the phenocrysts will change toward equilibrium with the
ambient conditions. For example, during mechanical mixing or
convection, magma parcels of greatly contrasting composition and
temperature are juxtaposed and may commingle. If mixing is sluggish
and the thermal regime changes gradually, zoned phenocrysts may
result. However, if disruption of equilibrium occurs suddenly during
vigorous mixing of relatively short duration, these oxide phenocrysts
may respond by internal exsolution. Carmichael (1967) cites evidence
that suggests the Fe-Ti oxides do not rapidly re-equilibrate to a
change in environment, and interaction between these phenocrysts and
the silicate liquid may be assumed to cease at the time the liquid is

quenched. Therefore, with the assumption that exsolution only effects

46
an internal rearrangement of these oxide phenocrysts, rather than a
change in bulk mineral composition, it should be possible to assess the
bulk composition of a single grain.

Several previous studies have attempted to obtain bulk analyses of
exsolved Fe-Ti oxide phenocrysts. In a study of Fe-Ti oxides from
compositionally zoned ash-flow sheets in southwestern Nevada (Lipman,
1971), which included four reported temperatures for the Topopah Spring
Member, bulk compositions of exsolved phenocrysts were obtained by
separate microprobe analyses of both the exsolved lamellae and the
surrounding matrix. These analyses were then combined based on
estimation of the relative contribution of each to the total area of
the phenocryst. Rutherford and Hemming (1978) rejected wet chemical
analysis because it was apparent that more than one composition of
fitanomagnetite occurred in the rocks under investigation and that
these phenocrysts contained abundant inclusions. Their solution was to
use the scanning capability of the microprobe to analyze several
sufficiently large areas across individual grains.

This study used similar method to that used by Rutherford and
Hemming (1978). Multiple analyses were collected along a trace across
each grain, where each analysis was performed by rastering the
microprobe beam over an area of 100112. This posed a problem in some
cases because the Hence-Albee correction program used in the data
reduction (Bence and Albee, 1968) assimes homogeneity of the area being
analyzed. This resulted in poor totals for chemical analyses of
inhomogeneous regions. Because the microprobe can only determine total
ircm, which is reported as Feo, it is necessary to compute a value for

Fe203 in order to recast the analyses into stoichiometric oxide

47
minerals and to assess the quality of the analyses (Carmichael, 1967).
Because analyses on unexsolved oxide phenocrysts invariably yielded
excellent totals, and determinations on the standard both before and
after each analytical session were reproducible, the recalculated
totals provide some indicatim of the degree of exsolution within the
analyzed area.

On the average, five grains each of magnetite and ilmenite were
analyzed for each sample, with an average of three analyses per
phenocryst. In some highly exsolved phenocrysts, as many as 10
analyses were performed. All multiple analyses of single grains were
averaged. With few exceptions, unexsolved phenocrysts were internally
homogeneous and unzoned, so that averaging of multiple analyses merely
increases the precision with which the bulk composition can be
reported. For the exsolved phenocrysts, it was assumed that averaging
of multiple analyses yields the closest approximation to the bulk
composition of the grain prior to exsolution. Those analyses that
could not be recast into a stoichiometric oxide phase or that yielded
recalculated totals less than 95 wt% were rejected from further
consideration. The remaining data set consists of ilmenite and
magnetite analyses from 46 samples, of which 25 are from individual
pumice samples (Table 3).

In order to strictly employ the ilmenite-magnetite geothermometer
to obtain an estimated quench temperature for an individual pumice
sample, it is necessary to demonstrate that a single pair of ilmenite
and magnetite phenocrysts and their surrounding glass coexisted in
mutual equilibrium at the time of eruption. This requirement would

generally be satisfied if a single composition of magnetite and

48
ilmenite were present within a sample. The range of 20 uncertainties
intemperauirearidoitygelifiigacityofthesolutim modelofSpencerand
Lindsley (1981) is reported assuming 31% uncertainties in Uspss and

Ilm compositions. This is interpreted to mean that if the

ss
compositional uncertainties in Uspss and Ilmss are 51% within a
single sample, then a single population of magnetite and ilmenite may
be assumed. However, in the Topopah Spring Member, the average
uncertainties in the mole fractions of Uspss and Ilmss within a
sample are approximately 3%. It is not clear whether this variation is
due to the presence of multiple magnetite and/ or ilmenite populations
within a sample, or whether this variation is an artifact of averaging
analyses from exsolved phenocrysts. Because it is not possible to
resolve this dilemma with the available data, the estimated
temperatures and oxygen fugacities presented herein are intended as
approximations only. All respective ilmenite and magnetite analyses
within a sample have been averaged to yield an ilmenite-magnetite pair
for each sample. This approach is not totally without precedent. In a
discussion of coexisting iron-titanium oxides of salic volcanic rocks,
Carmichael (1967) states that "As there is little to no zoning in all
the oxide minerals, the bulk analysis derived from the probe data of
between 15 and 20 grains should very closely approximate to their bulk
composition." (Carmichael, 1967, p. 43). Although Carmichael was not
referring to exsolved phenocrysts, the intra- sample variation in this
study is of the same or smaller order of magnitude.

Figure 9 illustrates the range in estimated quench temperature and
oxygen fugacity for the samples of the Topopah Spring Member based on

the mean composition of ilmenite and magnetite phenocrysts within a

49

 

 

 

 

 

I
W0
NO
25 L 1 I l l I l
600 700 800 900 1000 1100 1200

T (°C)

Figure 9. Estimated quench temperature and oxygen fugacity determined
from coexisting ilmenite and magnetite phenocrysts. MNO, NNO, and FMQ
indicate the experimental buffer curves for Mno- Mn 0 , nickel-
nickel oxide, and fayalite-magnetite-quartz, respectively, at 1 bar
total pressure (Haggerty, 1976).

50

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Chemical variation with estimated quench temperature.
Sioz in weight %, all other elements in ppm.

pumice; open symbols = whole-rock tuff.

Solid symbols = whole

52
sample. Also included are four data points recalculated from analyses
previously published by Lipman (1971). These temperatures and oxygen
fugacities were calculated according to the method of Spencer and
Lindsley (1981) using a modified Fortran version of their computer
program TFOZ. The mole fractions of ilmenite and ulvospinel were
calculated according to the method prescribed by Stormer (1983), using
a modified Fortran version of his computer program OXYCALCZ. This
latter program also calculates mole fraction values according to the
schemes suggested by Carmichael (1967), Anderson (1968), and Spencer
and Lindsley (1981). The deviation among these various methods has
been thoroughly discussed by Stormer (1983). For the samples
considered in this study, the difference in the calculated temperature
and oxygen fugacity using the various methods is invariably less than
the estimated model errors including the 20 compositional uncertainty.

The temperature data in Figure 9 range from 650 to 985‘C and show
nearly continuous variation from approximately 700 to 900°C. Within
this range, however, there appears to be a dichotomous distribution of
the glassy pumice samples (solid symbols), evident by the absence of
data in the interval from 786 to 812°C and the steeper slope of the
oxygen fugacity trend for the lower temperature group.

As one might predict from the extreme chemical heterogeneity among
pumice samples within the uppermost horizon of the ash-flow sheet, the
estimated quench temperatures of individual pumice samples at this
level span the entire temperature range of the eruptive sequence.
Figure 10 illustrates this variation in estimated quench temperature
with stratigraphic height at each of the sample locations. The open

symbols, which represent samples of whole-rock tuff, show relatively

53

little variation in quench temperature throughout the crystal-poor
rhyolite, with a notable increase within the crystal rich caprock.
Thus, the degree of heterogeneity in the compositions of the
iron-titanium oxides and their respective temperatures, within and
among pumice samples at a given stratigraphic horizon, correlate fairly
well with the chemical heterogeneity at the same level.

Figure 11 illustrates the variation of several trace elements and
Sioz with estimated quench temperature. All the trace elements show
similar trends when plotted against Sioz (cf. Figure 8), but opposite
in direction. There is considerably greater scatter in the
distribution of these elements for estimated quench temperatures above
800 C, which distinguishes the two populations that correspond to the
high-silica rhyolite and lower silica quartz latite samples. This is
most clearly illustrated by the solid symbols which represent the
glasq pumice samples. As noted previously, these two populations are
more prcnainced for the compatible elements and these elements are more
abundant in the quartz latite. It is also apparent that the two
somewhat higher estimated temperatures of 981 and 985°C correspond to

pumice samples that are among the most mafic in composition.

Sil' icate Phenocmst and Glass ggmpggitions
A common feature of compositionally zoned ash-flow sheets is the

progressive increase in the abundance and variety of phenocrysts with
stratigraphic height, which is interpreted to reflect a corresponding
increase with depth in the magma body. As noted in the description of
the Busted Butte section (p. 10), the variation in phenocryst content

increases uniformly upward from 1 to 6% in the high-silica rhyolite,

54

and increases to approximately 21% at the transition to quartz latitic
caprock. Although the rate of increase in phenocrysts changes
abruptly, Lipman et al. (1966) reported that no discontinuity in
phenocryst content or in other physical aspects of the tuffs is evident
at this transition, and that the changes appear to be entirely
gradational. However, their description of this gradational change in
phenocryst abundance is based on observations of whole-rock tuff, and
therefore the exact nature of the gradient in phenocryst abundance
within the magma body is not clear. In lieu of the discontinuities in
chemical composition among the pumice samples, similar discontinuities
in phenocryst abundance, composition, and variety may be expected to
occur at the interface between magmas of contrasting composition,
temperature, and water content. Whether such discontinuities are
preserved or obscured would depend on the degree of interaction between
the contrasting magmas. Because of the large uncertainties in modal
determinations in thin sections of pumice samples with relatively few
phenocrysts, the following discussion will emphasize compositional
data. Descriptions of the chemical compositions of the phenocrysts
will focus on those aspects that are sufficient to evaluate the
hypothesis of a magmatic interface and to determine the degree of
interaction (commingling) of the contrasting magmas.
Bietite

Biotite is the only ferromagnesian silicate that occurs throughout
the eruptive sequence. Phenocrysts vary in abundance from
approximately 0.05% in the high-silica rhyolite to 0.9% in the quartz
latite, and typically occur as euhedral grains, 0.5 mm in length.

Twenty four pumice samples that are representative of the total

55
variation in pumice composition were selected for analyses. Microprobe
analyses of biotite from these samples are presented in Table 4.

Individual biotite phenocrysts are relatively homogenous and
unzoned, although a few grains were observed with overgrowths of a
different biotite composition. This is in contrast to biotites from
the Bishop Tuff, which are reported to be the most inhomogeneous
phenocryst in the tuffs (Hildreth, 1977). Warren et al. (1984) report
an unusual (herringbone) type of alteration for biotite in lithic
fragments of the high-silica rhyolite portion of the Topopah Spring
Member, and note that biotite with identical alteration is found in the
gmmdmass of samples from this horizon. Analyses of these altered
biotites (Warren et al., 1984) are 4 to 5 wt.% higher in SiOz than
those from fresh samples, and have molecular Mg/(Mg+ Fe) greater than
0.80. No such alteration textiires or compositions were observed in any
of the biotites from this study, which are all phenocryst separates
from pumices samples. It therefore seems safe to conclude that the
altered biotites were derived solely from lithic fragments and were
not xenocrysts in the magma. Because individual phenocrysts are
generally homogeneous, it was decided that a single analysis near the
edge of the grain was the most efficient way to evaluate compositional
variations among grains.

A single compositional parameter, the molecular Mg/(Mg+Fe) or Mg#.
is used to facilitate comparison of the biotite analyses, as iron and
magnesium display the largest variation (Barium also shows considerable
variation, ranging from below detection in biotites from the
high-silica rhyolite (<0.09 wt.% BaO) to a maximum of 4.68 wt.% BaO in

biotites from the quartz latite) . The compositional variation of all

56

 

 

 

 

 

 

 

 

 

 

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0.35 0.45 0.55 0.55 0.75
Blotite Mg#

Figure 12. Histogram of Mg# for 617 biotite phenocrysts from 24 pumice
samples, calculated from microprobe analyses in Table 4.

57

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Figure 13. Mg# of biotite phenocrysts within pumice samples in
relation to stratigraphic position in the Busted Butte section.

58

ll' Sample SiOz T "C Level
+ --------- + --------- + --------- +-|l l--+ --------- +-BBQ-10Cx 67.7 862 U
. ......... + ......... + ......... llllllnl-+l ........ +-339-sc* 69.2 981 U
+ --------- + --------- + --------- +||l |---+ --------- +-BB9-IB* 69.6 - U

+ --------- + --------- + --------- +-l- Illll—+ --------- +-LW1-A 70.6 878 U
+ ......... ... ......... + ......... +'llll|+ ............ 41.33940! 70.? 890 U

+ ......... + --------- 4- --------- +-l l|l||+ ------------ +- CP3-2A 70.7 985 U

+ ......... + ......... + ......... I---| ---. ......... ..-sz-A 70.8 883 U

Biotite M¢#

Figure 14. Mg# of biotite phenocrysts within pumice samples in
relation to whole-pumice Sio content, estimated quench temperature,
and stratigraphic horizon U = upper level; L = lower level). An
asterisk following a sample name indicates a combined sample of
texturally identical pumices (see text).

59

Sample 310: TaC Level
+ “““““ 4' """"" + ---------- +l ---+ --------- +- CP3-ZB 70.8 884 U

+ ......... +¢¢l ...... + ........... :lllll--+ ........ +" Lw4-103

70.9 - U
1 ......... 1 ......... . ......... .-- II..-+ ......... +-cpa-10 71.0 862, u
+ --------- + --------- + --------- +--Il Ill-4» --------- +-LW4-SB 71.3 895 U
+ ......... ... ......... 4. ....... l'l ll ————— + --------- ‘-LW4-IB3 73.1 695 U

+ --------- 4.-.]. ----- + --------- +--- l--+ --------- +-Lw2-5

73.2 896 U
0.30 0.40 0.50 0.60 0.70 0.80

Biotite Mzt

Figure 14b.

60

I Sample SiOz T °C Level
+ ------------ Il+ ----------- + -------- + --------- +-339—1At 75.9 815 U
+ ........ lilll- L L I+---JL--+ --------- + --------- +-603-11x 75.9 743 L.
+ ......... + ......... .---Llllllll ....... + --------- +-888-38 76.8 762 I.
+ ......... JJLIIIL ...... I"III-l-l---+-------—--+-BBS—853# 76.9 759 L.
+ --------- +lllll---l+ --------- + --------- + --------- +-BBB-20 77.0 686 L
+ ......... .--"IIIJI ..... "I“ ......... + ......... v-BBS-ISB 77.0 778 L
. ......... .llll-l---+ ......... + --------- + ---------- CPI-3A 77.9 784 L
+ --------- +-llll----+ --------- +--I--l---+ --------- +-LW4-5Ax 78.2 - U
+ --------- + ------ I .--l--l---+ --------- + ----------- BB8—1 78.3 750 L
+ ........... +| ll I---+ ......... + ......... + --------- .-LW2- 10 78.7 887 u
+ --------- :-'l'll—--+ --------- + --------- + -------- +-BBS-5 7&8 - L
0.30 0. 40 0.50 0.60 0.70 0. 80

Biotite M8#

Figure 14c.

61

617 biotite analyses is presented in Figure 12. There is a total range
in Mg# from 0.39 to 0.71, and a clearly bimodal distribution with modes
at 0.44 and 0.65 corresponding to the high-silica rhyolite and quartz
latite pumice samples, respectively. Biotites with an Mg# in the range
of 0.50 to 0.60 are relatively scarce, and within this range, there is
a small compositional gap between 0.50 and 0.53. This distribution of
biotite compositions is interpreted to reflect the variation of
liquidus cmditions in the magma, and is consistent with the idea of a
layered magma body. Biotites with Mg#50.50 were derived from the
high-silica rhyolitic layer; those with Mg#_>_0.60 were derived from the
quartz latitic layer, and biotites within the range 0.535Mg#50.60 were
derived from the interfacial region between the two magma layers.

The compositional variation of biotites within individual pumice
samples is depicted in Figures 13 and 14. Figure 13 illustrates the
variation of biotite Mg# in pumice samples according to their
stratigraphic position in the Busted Butte section. Figure 14 displays
the variation of biotite Mg# for all 24 pumice samples (11 quartz
latites, 11 high-silica rhyolites, and 2 intermediate rhyolites) , which
are arranged in order of decreasing whole-pumice silica content. All
of the quartz latite pumice samples (67.7-71.3 wt.% Sioz) contain
biotites with Mg# 2 0.60, with the exception of LW4-1OB which also has
a single biotite with an Mg# of 0.43. In contrast, all of the
high-silica rhyolite pumice samples (275 wt.% $102) contain biotites
that generally have Mg# 5 0.60.

Several of the pumice samples contain a few biotites that have
compositions distinctly different from the dominant population or

display a bimodal distribution. Although the implication of a

62

disequilibrium phenocryst assemblage is clear, extreme caution must be
exercised in this interpretation here. It was noted in an earlier
section that several of the pumice samples are combinations of
texturally identiml pumices fragments, necessitated because of their
small size. It is emphasized that the colors of the glass of the
different pumice types are sufficiently distinct that the choice of
which pumice fragments to combine is straightforward, and it is highly
unlikely that pumice fragments from the extremes of the compositional
range were combined. While the author has a high degree of confidence
that the pumice fragments that were combined were in fact identical,
the subjective nature of this choice, and the simple fact that they are
not single parcels of quenched magma, makes suspect any attempt to
interpret variations within these samples. Therefore, although the
heterogeneities are not considered to be artificially induced, the
combined samples are indicated by an asterisk to allow the reader to
ignore them if desired. In this paper, any of the conclusions based on
heterogeneities within samples, will rest firmly on evidence from
single, uncombined pumice samples.

In Figure 14, five of the nine combined pumice samples display
unimodal biotite compositions, so that no artificial heterogeneity
appears to have been induced in these samples. Four of these are
quartz latites (BBQ-10C, BBQ-5C, BBQ-13, and BBQ-1C), and the fifth
sample (LW4-lB) falls between the quartz latite and high-silica groups
at 73.1 wt.% 5102. Ten of the samples in Figure 14 display either a
bimodal distributicm or a sufficient range in biotite composition to be
considered as evidence for magma mixing or commingling. All four of
the combined pumice samples that display phenocryst heterogeneity are

63

high-silica rhyolites, and in two of these samples (BBQ-1A, LW4-5A),
the expected low Mg# biotites predominate, with only a few biotites in
the range of Mg# 0.63 to 0.66. Both of these samples occur within the
upper few meters of the ash-flow sheet and are interpreted to reflect
limited commingling of the high-silica rhyolitic and quartz latitic
magmas during the final stages of the eruptim. The other two combined
samples that display hazerogeneity. (BBS-853 and SUB-11) are fiamme from
the lower portions of the ash-flew sheet (cf. samples 14 and 64 in
Figure 2). The majority of biotites in sample GUB-ll occur within the
Mg# range expected for the high-silica rhyolites, and the small amount
of heterogeneity is interpreted to indicate commingling of high-silica
rhyolitic magma with magma from the interfacial region. Sample BBB-858
clearly displays a bimodal distribution of biotite compositions, with
nearly half of the biotite analyses having an Mg# that indicates
derivation from the quartz latitic magma and the region near the
magmatic interface. Even if one denies the possibility that this
sample represents commingled magma because it is a combined sample, the
fact that biotites with Mg# 2 0.60 occur at this level suggests that
some of the quartz latitic magma was deposited relatively early during
the eruption.

There are six uncombined, single pumice samples shown in Figure 14
that contain a heterogeneous distribution of biotite phenocrysts, and
are considered to be unequivoal evidence of magma commingling on the
scale of a single pumice fragment (LW4-IOB, LWZ-S, BBB-38, BBB-20,
BBS-158, and BBB-1). Sample LW4-1OB is a quartz latite pumice fragment
with all but one of the biotites having Mg# > 0.6; the single biotite

with an Mg# of 0.43 is characteristic of biotites from the high-silica

64

rhyolite. Similarly, sample LW2-5 is dominated by biotites in the
range of Mg# 0.64 to 0.67, with only four biotites in the range of Mg#
0.43 to 0.44. The phenocryst heterogeneity in this sample (LW2-5, 73.2
wt.% Sioz) is particularly noteworthy in that it supports the
hypothesis that the few pumice samples that occur in the interval of
the previously noted compositional gap between the quartz latite and
the high-silica rhyolite (71.8 to 74.7 wt.% $102) formed from limited
mixing of the two contrasting magma types. The other pumice sample
that occurs in this interval (LW4-lB, 73.1 wt.% Sioz), appears to
have a unimodal distribution of biotite compositions, although the mean
Mg# is slightly lower than that of the quartz latites, and several
biotites have Mg# < 0.60. The difference in biotite compositions
between these two intermediate samples may reflect a difference in the
relative positions of the end member magmas in the chamber (i.e.,
distant from or close to the interfacial region), and hence, in the
timing and the degree of equilibrium attained after the mixing event
("commingled" versus "mixed"). Samples BBB-20, BBa-l, 888-38, and
BBB-153 are all high-silica rhyolites, and the heterogeneous
distribution of biotites within these samples is indicative of
commingling of magma from various positions within the rhyolitic layer,
and of commingling of high-silica rhyolitic magma with magma from the
interfacial region and the quartz latitic magma.

In summary, the following conclusions may be drawn from the
compositions of biotite phenocrysts and their distribution within and
amcmg single pumice samples: ( 1) the bimodal distribution of biotite
compositions from the high-silica rhyolite (Mg#=0.44) and the quartz

latite (Mg#=0.65) pumice samples, and the relative scarcity of

65

compositions in the interval from 0.5 to 0.6, supports the hypothesis
that the transition from high-silica rhyolitic to quartz latitic magma
within the chamber was abrupt, with a liquid-liquid interface
separating the two contrasting magma types; (2) biotites within the
high-silica rhyolite pumice samples range from Mg# 0.39 to 0.50,
suggesting that the high-silica rhyolitic magma was zoned, and that
biotites in the range of Mg# 0.53 to 0.6 crystallized near the
interface: (3) the occurrence of biotites with Mg# 2 0.6 in the lower
horizon of the ash-flow sheet, indicates that plumes of quartz latitic
magma may have risen into the high-silica rhyolitic magma during early
stages of the eruption; (4) the presence of biotite phenocrysts from
the extremes of the compositional range, within single pumice
fragments, provides evidence that limited magma mixing or commingling
between the high-silica rhyolitic and quartz latitic magma occurred
during the eruption.
W2

Consistent with the hypothesis of a magmatic interface is the
ubiquitous occurrence of pyroxene phenocrysts in all of the quartz
latitic pumice samples, and the notable lack of pyroxene in the
high-silica rhyolitic pumice samples. 0f the 24 pumice samples in
whidn biotites were analyzed, 14 contain pyroxene and only one of these
is a high-silica rhyolite (LW4-5A). Not surprisingly, only one
pyroxene grain was found in this high-silica rhyolitic pumice sample,
which also contains a bimodal distribution in biotite composition.

In the quartz latite, euhedral pyroxene phenocrysts average 0.5 mm
in length and reach an abundance of approximately 0.4%. Microprobe

analyses of the edges of pyroxene phenocrysts are presented in Table 5.

66

 

 

En

 

 

 

 

 

 

 

E“ Fs

Figure 15. Compositional variations of pyroxene phenocrysts within
pumice samples: data from microprobe analyses in Table 5.

67

l I Sample 510. 7°C Level

+ ......... + ........ II---I-IIIII III I-II+---II----+-889-noa 67.7 862 u
+ ......... IL—I ..... +I---I-I_I+I-IIIIIIII-LI-L--+-889-5c: 69.2 981 u
+ ......... + --------- + ....... I-+-—II-IIIIIIII----I-+-889-1Bx 69.6 - U
. ......... ... ....... I-+ ...... I--II-I-IIIIII-III ..... +-Lw1-A 70.6 878 U
. ......... . ......... .--I ...... .-I----III|---..-I---.-...-m. 70.7 .9. u
. ......... . ....... ll.----ll-ll.l-|llllIII|ll.."ll-.-¢p3-2A 70,, 935 U
+ ......... + ...... I-—+ ........ I+IIII--IIII ......... +-Lw2-A 70.8 883 u
+ ......... + ...... I--+I ..... IIIIJIIIIIIIII ........ +-CP3-ZB 70.8 884 U
+ ......... + ......... +I ........ +--I ----- I+-I--I----+-Lw4—108 70.9 - u
+ ......... + ........ I+-I-III-I-IIIIIIII-II ......... +-cpa-10 71.0 862 U
+ ......... + ......... + ......... +-II-I--I-+I -------- +-LW4-SB 71.3 895 U
+ ......... + ...... I-I+I-I“II-IIIIII---I-+ --------- +-Lw4-18x 73.1 695 U
+ ......... + ......... +----I----IIIIII--II+ ......... +-LW2-5 73.2 896 U

0 . 60""-"0:66"-"-BT;B"""ST;§"J“5T63“"--07EEWMM 7” - U

PYroxene Mg#

Figure 16. Mg# of pyroxene phenocrysts within pumice samples in
relation to whole-pumice sic content, estimated quench temperature,
and stratigraphic horizon %U = upper level; L = lower level). An
asterisk following a sample name indicates a combined sample of
texturally identical pumices (see text).

68

 

 

 

 

 

 

 

 

 

 

 

40 I r F I

30 - r ~
>
U _ ...
C _
OJ
3 20 ' r
0'
OJ L. ..
L "' -...
U- I!

10 " .7

 

 

 

 

 

0.60 0.65 0.70 0.75 0.80 0.85
Pyroxene Mg#

Figure 17. Histogram of Mg# for 307 pyroxene phenocrysts from 14
pumice samples, calculated from microprobe analyses in Table 5.

69

The compositional ranges of pyroxenes within pumice samples are
illustrated in Figures 15 and 16. All but two of the pyroxene analyses
plot in the augite field (Figure 15), the exceptions being a subcalcic
augite (CP3-2A) and a clinohypersthene (BB9-1C). Although there is
considerable scatter in the iron-magnesium ratios of the pyroxenes
(Figure 16), the mean Mg# of the pyroxenes within each pumice sample
falls within a relatively narrow range between 0.74 and 0.79 and lies
within one standard deviation of the mean for all pyroxene analyses
(Figure 17).
Hornblende

0f the 24 pumice samples in which ferromagnesian silicates were
analyzed, only four were observed to contain hornblende. Previous
sundies of the Topopah Spring Member (Lipman et al., 1966; Byers et
al., 1976) reported the presence of trace amounts of hornblende in the
quartz latitic caprock only. However, three of the four pumice samples
that contain hornblende are high-silica rhyolites, and two of these are
from the base of the ash-flow sheet. Microprobe analyses of the
hornblende phenocrysts are presented in Table 6, and their
compositional variation in terms of Mg# is plotted in Figure 18.
Because of the paucity and erratic distribution of hornblende in the
pumice samples, they are of little use in evaluating the hypothesis of

a magmatic interface.

70

Sample 510. 7°C Level

+ ......... + ......... +-II-II---+-I-------+---------+- CP3-ZA 70.7 985 u

+ ......... +---I ..... +I ........ + ....... I-.. ......... +- 888-158 77.0 778 L

. ....... IIIIJI ..... + ......... + ......... + ......... +-CP1-3A 77.9 784 L

+ --------- +'--l-"--+ --------- + --------- + --------- +-LW4-5A¥ 78.2 - U
0.45 0.50 0.55 0.60 0.65 0.70

Hornblende Mg#

Figure 18. Histogram of Mg# for 22 hornblende phenocrysts from 4
pumice samples, calculated from microprobe analyses in Table 6.

71
Feldspa;

Plagioclase and sanidine together make up approximately 90% of the
total phenocryst assemblage in both the high-silica rhyolite and the
quartz latite. Plagioclase abundances vary from 0.5% in the
high-silica rhyolite to 7.3% in the quartz latite and sanidine
abundances vary from 0.4% in the high-silica rhyolite to 11.6% in the
quartz latite. Both feldspars occur as well formed crystals averaging
1 mm in length, however, sieve textures and embayed crystal faces are
common, particularly in phenocrysts from quartz latitic pumice
samples. Microprobe analyses of plagioclase and sanidine phenocrysts
are presented in Tables 7 and 8, respectively.

The compositional variations of the feldspars are complex, due in
part to the strong zoning profiles in some of the phenocrysts. The
zoning profiles of plagioclase and sanidine phenocrysts from four
pumicesamplesareshowninFiguresBandZO. Thedatapointsineach
ternary diagram are from a single phenocryst, with the smaller symbols
representing analyses of phenocryst centers and the larger symbols
representing analyses of phenocryst edges. In Figure 21, each ternary
diagram illustrates the variation of only the edge compositions of
feldspar phenocrysts within a single pumice sample. The samples
depicted in Figure 21 span the entire range in whole-pumice chemical
compositions. Although the variation of feldspar edge compositions
within pumice samples is relatively large, and there is overlap between
samples, it is possible to distinguish a dominant edge composition that
is presumed to be the equilibrium composition for a given pumice
sample. In general, the plagioclase in the quartz latitic pumice

samples is more calcic, less sodic, more potassic, and contains more

72

 

 

 

An
18 m- o
.0 £5
A0 A" Dr
CP3-23
U
'% b % g 3
AD An 0p
0 g, an
AD 07‘

Figure 19. Zoning profiles in plagioclase phenocrysts from pumice
samples. Each ternary diagram represents a single phenocryst. Large
open squares =- edge analyses: small asterisks = center analyses.

73

An

Ab Or‘

888-158

An

A0 00

Figure 19 (cont'd.) .

74

An

BBQ-10C

Ab. 0r‘

An

 

 

Ab OP

Figure 19 (cont’d.) .

75

An

    

CPS-28

 

 

 

 

 

 

 

 

Eh;
[1---1-ae__1\
[_ 1-_a-.._,_Y
L...__.l
[_‘_‘_...___j
L_eelm_1_l\ M
Z- _1°5___1\
Ab 0r

   
 
       

BBQ-10C

 

 

 

 

[_‘i-o- :i\
LAMP»- \
Lew“ R
All Or‘

Fflmnxl 20. Zonnr; pnmfiles :hn semkfine Itenomgets lkom Ignace
lemqfles. Itch.'Uesemy'dflepzmlrepneimtseasungleldxextryst. large
open experes == edge anedyses; smell anflrmuSks == cemanranahwesh

An

76

 

 

AD

Or‘ An

    

888-158

 

 

 

 

 

 

[,--e_i- A
fireelm111§_
[1-88mi \
/ ... ..- T

Or‘

kanxzzo uxxmfd.).

77

An
An
I?
A g
O 1Q ‘v
m.
An qr;
An 7: o
5"
4‘- 60:
o
.9 3 m
I
g: (I:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1-1-18111_1\
0m!!- \ 0P
AAAA‘A‘L‘ Or
AU Or A An
n
An Q
A” V "a"
An ., ”7'3
’ Q
An (a 4? (p
.1? a;
:65
bl Q Q
I Q U
9 Q
\I
I
I
““fihh—Q—ges
I u . .\
- _ --
0! a g -“‘_ 4‘\ 0p
‘9 a, -—-m \ Or‘
m‘*--J..—_1\ 0"
m-JS-e---\ 0"
0r~
Ab 0r

Figure 21. Compositional variations of microprobe edge analyses of
feldspar phenocrysts within pumice samples. Data from Tables 7 and 8.

78
barium than the plagioclase in the high-silica rhyolitic pumice
samples. Sanidine in the quartz latitic pumice samples is more calcic,
more sodic, less potassic, and contains more barium than the sanidine
in the high-silica rhyolitic pumice samples. For example, the dominant
plagioclase composition in quartz latitic pumice CP3-2A is
An26Ab640r10 compared with An17Ab-760r7 for high-silica
rhyolitic pumice BBB-1. Similarly, the dominant sanidine composition
in CP3-2A is An4Ab420r54 compared with AnlAb3-70r62 for
BBB-1. These compositional differences between feldspars from the
quartz latitic and high-silica rhyolitic pumice samples are consistent
with the interpretation that the magmatic liquid was compositionally
stratified before the onset of crystallization. Furthermore, the
compositional differences among feldqnars within single pumice samples

provide additional evidence of magma commingling during eruption.

W

A knowledge of the liquid composition of the Topopah Spring magma
is crucial in evaluating the hypothesis that the magma body was
layered. Bubble walls of glassy pumice fragments provide the closest
approximation to quenched samples of the liquid portion of the magma,
and can be easily analyzed using the microprobe, thereby avoiding
problems of obtaining clean glass separates and allowing determination
of the degree of homogeneity of the glass within a pumice fragment.
Microprobe analyses of bubble walls from 10 representative pumice

samples are presented in Table 9.

79

Sample 510: ’1' °C Level

+ ......... + ...... III+ ------ II-II-II ----- I---U ----- +-BBS-IOC¥ 67.7 862 U
+ --------- + --------- + ------- '-+ --------- ...-o ------- +-BBS-SCt 69.2 981 U
+ ....... I-+I ........ + --------- I-I-I---III--n ------ +-CP3-2A 70.7 985 U
+ --------- + --------- +II--I'll-.|'nl----+-U ------- +-CP3-ZB 70.8 884 U
+ --------- .---IIII--+---0 ..... + --------- + --------- +°LW4-IB* 73.1 695 U
+ --------- +'--'----'+-ll-IIDI-+ --------- + --------- +-Lw2-5 73.2 896 U
+----III-III-I-a----+ --------- + --------- + --------- +-888-38 76.8 762 L
+--II-III-+-a ....... + ......... + ......... + --------- +-888-158 77.0 778 1.
+----I'I-I+ --------- + --------- + --------- + --------- +-BBB-l 78.3 750 L
+---II'ID-"-I ...... + ......... + --------- + --------- +—CP3-1A 78.4 724 U
.000 0.015 0.030 0.045 0.060 0.075

Ti Cations/32 Oxygens

Figure 22. Histograms showing compositional variations in titanium in
the bubble walls of pumice samples. Ti atims calculated on the basis
of32 oxygensfrommicrcprobedatainTable9. Lightcolcredsquare on
baseline shows the composition of the whole-pumice calculated on the
same basis from the data in Table 2.

80

I Sample 510. T ’0 Level

+ --------- + ------- '-+ -------- I'Il-l-B' -.--l------+-BBQ-IOC$ 67.7 862 U
+ --------- + --------- + --------- +--Cl ------ +--' ------ +-BBS-50¥ 69.2 981 U
+----II--I+--I ...... 4--I--n---+ ...... II-III' ------- l-CP3-2A 70.7 985 U
+ --------- + --------- + ------- I "D ------ + --------- +-cp3-28 70.8 884 U
+ --------- +--IIIIL-+ ......... + --------- + --------- +-1.w4-18t 73.1 695 U
+ ......... + ..... n---+-IIIIIII—I-II--I---+ ......... +-LW2-5 73.2 896 u
.--l..-lIBI+I ........ + --------- + --------- + ----- I---+-BB8-38 76.8 7 62 L
+l----II-D" -------- + --------- + --------- + --------- +-BBB-ISB 77.0 778 L
0 ...... I.-. ......... + ......... + ......... + ......... +-888-1 78.3 750 1.
til---Il..|'«l- --------- + --------- + --------- + --------- +-CP3-1A 78.4 724 U

2.50 2.75 3.00 3.25 3.50 3.75

Al Cations/32 Oxygens

Figure 23. Histograms showing compositional variations in aluminum in
the bubble walls of pumice samples. Al cations calculated on the basis
of 32 oxygenns from microprobe data in Table 9. Light colored square on
baseline shows the composition of the whole-pumice calculated on the
same basis from the data in Table 2.

81

It was noted earlier that the composition of the glass may differ
from that of the magmatic liquid because of volatile loss and secondary
hydration. An additional complexity is the possible volatization of
sodium by themicroprobe beam (Nielsen and Sigurdsson, 1981). In lieu
of these difficulties, discussion of the glass compositions will be
limited to consideration of the elements titanium and aluminum, as
they are considered to be relatively stable (Lipman, 1965). The glass
analyses were recalculated to cation proportions on a 32 oxygen basis,
and histograms of the Ti and Al data are presented in Figures 22 and
23. The Ti and Al concentrations in the glass show a general increase
in concentration with decreasing whole-pumice $102 content that is
parallel to the whole-pumice Ti and Al concentrations. The glass
analyses of the high-silica rhyolitic pumice samples show relatively
little scatter, and their nearness in concentration to that of their
respective whole-pumice is consistent with the low abundance of
phenocrysts in these pumice samples. In contrast, glass analyses of
the quartz latitic pumice samples show greater variability, and the
higher concentration of Ti in the corresponding whole-pumice reflects
the influence of the greater abundance of mafic phenocrysts. Glass
analyses of the pumice samples with intermediate whole-pumice Sioz
content have Ti and Al concentrations that are intermediate between
those of the high-silica rhyolitic and quartz latitic pumice samples,
consistent with the earlier contention that they are mixed rocks. In
particular, sample sz-S shows the greatest degree of glass
heterogeneity of the intermediate pumice samples, and also shows the
greatest degree of heterogeneity with respect to biotite and feldspar

compositions (cf. Figures 14b and 21).

82
It is apparent that there is a greater degree of heterogeneity
within pumice samples from stratigraphic levels where there is a
greater degree of heterogeneity among pumice samples. This is not
surprising considering that the pumice samples from the upper level of
the ash-flow sheet were ejected later in the eruption, and thus had a
greater cpportunity to commingle with overlying magma of contrasting

compositions.

e ' e V

Several previous studies that include phenocryst data from the
Topopah Spring Member have also suggested that the compositional
variations of liquidus phases resulted from growth in a magma that was
compositionally zoned prior to the onset of crystallization, although
these studies used samples of whole-rock tuff (Lipman et al., 1966;
Byers et al., 1976; Warren et al., 1984; Broxton et al., 1982). More
recent work has suggested that there are also differences in the REE
phases between the lower and upper units. Scott et al. (1984) have
shown that the REE phase in the rhyolitic units is allanite, whereas in

the quartz latitic units the REE phase is perrierite/chevkinite.

DIS CUSSION

0 ' ' u 'c te e

The chemical, mineralogical, and textural heterogeneity within and
among pumice samples in the Topopah Spring Member clearly emphasizes
the importance of the scale of observation when evaluating petrogenetic
processes. 0n the scale of a handsample of whole-rock tuff, the
progressive variation from crystal-poor high-silica rhyolite to
crystal-rich quartz latite with increasing stratigraphic height was
inferred to reflect the trend toward increasingly more mafic,
crystal-rich, high temperature magma with depth in the chamber (Lipman
et al., 1966). On the scale of individual pumice samples, however, the
relationship between stratigraphic position in the ash-flow sheet and
depthinthemagmadnamberneedstobereevaluated because there is a
variation in the compositions and estimated quench temperatures among
pumice samples at any given stratigraphic level. Rather than assuming
a chaotic state in the magma body, this compositional and textural
heterogeneity is inferred to result from simultaneous eruption of
compositionally contrasting magma from different parts of a magma
chamber that was systematically zoned with respect to composition and
temperature. Not only is there a host of evidence from other ash-flow
sheets that indicates depth-dependent compositional and thermal
gradients within magma chambers, but the theoretical fluid dynamic
regimeofmagmawithdrawalfromazonedmagmachamberpredictsthat in
most cases, the chamber will not be simply emptied in a layer cake
fashion. For example, Blake (1981) comments that this view that

ash-flow sheets simply represent inverted magma bodies is too

83

84

simplistic because this would require an unrealistic flow pattern of
magma renoval. Blake (1981) approached the problem by a mathematical
analysis of the removal of magma from a chamber by applying the
solution of Weissberg (1962) for the velocity field within a large
flat-topped reservoir as a fluid flows upward into a cylindrical
conduit. If the diameter of the conduit is considerably smaller than
the diameter of the reservoir, fluid will approach the conduit from all
directions in a radial fashion, not just from directly below it. At
large horizontal distances from the conduit, the radial component of
fluid velocity is small in comparison to that directly below the
conduit. Hence, the net, or angular velocity field developed near the
entrance region to the conduit results in a parabolic velocity profile
composed of hyperbolic streamlines along which fluid accelerates
towards the conduit (Blake, 1981). By considering this velocity
profile, one can determine the sub-circular locus of points within the
fluid reservoir that will reach the conduit entrance at the same time.
This hyperbolic profile, or "eruption isochron", as defined by Blake
(1981), relates position within the reservoir to time of entrance in
the conduit for a given eruptive volume. General theoretical solutions
describing the dynamics of magma withdrawal and the geometries of
evacuation isochrons for assumed boundary conditions have been
presented by Blake (1981), Blake and Ivey (1986a, b), Spera (1983,
1984), and Spera et al., (1986).

Figure 24 is a highly schematic cross-sectional cartoon that
illustrates the general model of a zoned magma body as proposed by
Smith (1979), on which several hypothetical eruption isochrons have

been superposed. Admittedly, this depiction is a gross

85

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

\
/ Erupted
volume
High-silica
rhyolite ‘
1
”W T
NN F r/‘
l l i/ “
Quartz latlte i
‘ l l l l ’
? 7 --------

Dominant volume

 

 

 

Eruption of the Topopah Spring Member

Figure 24. Cross-sectional cartoon of a layered magma body. Circles
represent cross-sections through hyperbolic eruption isochrons (Blake,
1981), indicating the locus of points within the magma chamber of magma
that will reach the vent simultaneously.

86

oversimplification, as the actual shapes of the 3-dimensional
hyperbolic surfaces will be governned by the geometries of the conduit
and reservoir and the physical properties of the magma. For example,
eruption through a ring fracture systen, which is more appropriate for
the Topopah Spring Member, would be better approximated by a toroidal
evacuation isochron with a large width to depth ratio. It is also
apparent from geologic field evidence that the conduit plumbing systems
of large caldera forming ash flows do not remain constant during the
course of eruption. Precise mathematical modeling of the evacuation
isochrons for these complex and transient geometries can quickly become
intractable. The more immediate goal of this study is to show that the I
chemical hezerogeneity of pumice samples in the Topopah Spring Member
is consistent with the qualitative predictions of the general fluid
dynamic models.

Figure 24 shows several of an infinite number of evacuation
isodnronsthatconldbeconsidered fromtheonsettothefinal phase of
eruption, with that representing the final phase having a volume equal
to the total volume of the eruption. Each successive evacuation
isochron will draw magma from progressively deeper levels at the
expense of magma near the roof of the chamber. However, as illustrated
by the largest isochron in Figure 24, magma near the roof of the
clnamber is not completely exhausted but is continually erupted along
with magma from all levels down to the deepest level tapped. Assuming
that the magmatic gradients change monotonically with depth in the
chamber, each successive isochron will sample magma of progressively
greater differences in chemical and physical properties. Thus, the

fluid dynamic model for eruption from a zoned magma chamber predicts

87

that successive volumes of magma leaving the vent will be composite
mixtures of magma with increasingly heterogeneous bulk properties.

The geochemical data from both the whole-rock tuff and whole pumice
samples are consistent with this model for subterranean eruption
dynamics. The whole-rock tuff samples, which become more mafic with
increasing stratigraphic height in the ash-flow sheet, represent the
bulk composition of a given eruption isochron and are composite
mixtures of quenched magma from various positions within the magma
chamber. The whole pumice samples, which span a progressively greater
compositional range with increasing stratigraphic height in the
ash-flow sheet, represent the composiin'on of quendned parcels of magma
from various positions along the periphery of an evacuation isochron.

There are several alternative mechanisms that might give rise to
compositional heterogeneity within a "depositional isochron". For
example, several ash flows that erupt from laterally separated vents
that extend to different depths in the magma chamber could coalesce
during emplacement to produce a composite mixture of compositionally
contrasting pumice fragments. The possibility of subaerial coalescence
during eruption from separate vents along the ring fracture system of
the Claim Canyon caldera must be considered and obviates the need for
development of criteria to distinguish between the effects of subaerial
mixing and subterranean mixing in the magma chamber/vent system.
However, it is emphasized that the fluid dynamic considerations
dismissed above would be applicable to each of the laterally separate
vents or semi-continuous segments along a ring fracture system. It
might also be considered that successive portions of a turbulent ash

flow could entrain and suspend pumice fragments of different

88
compositions as the ash flow passed over earlier erupted material.
Subaerial mixing undoubtedly occurs to some extent, however, it is
difficult to conceive of how pumice fragments from the top of the
ash-flow sheet, that are identical in composition and estimated quench
tenperature to pumice fragments from the base of the sheet, could be
continually rafted upward for the duration of the eruptive episode.
Spera (1984) has noted that the time interval that a parcel of magma
wendsinthesubaerialrealmbeforecomingtorest is on the order of
102 s in comparison to 104-405 8 for the duration of an eruptive
episode. Moreover, the heterogeneities in phenocryst and glass
compositions within single pumice samples provide clear evidence of
subterranean mixing. The ocoirrence of macroscopically banded pumice
fragments, such as those observed in the Valley of Ten Thousand Smokes
and Crater Lake eruptives (Smith, 1979: Bacon, 1983, Hildreth, 1984)
would provide further evidence for subterranean mixing, however, its
apparent absence is not a limitation. In a study of the Black Mountain
volcanics, Vogel et al. (in press) have documented the occurrence of
unzoned, disequilibrium phenocryst assemblages within individual pumice
samples that have homogeneous glass compositions. They conclude that
the mixing event was vigorous enough to homogenize the liquid, yet
short enough to inhibit zoning of the phenocrysts. Whether diverse
compositions of a stratified magma body will be simultaneously
withdrawn, and the degree to which the diverse compositions may mix
will be largely governed by the driving force of the eruption and the
viscosities of the magmas (Blake and Ivey, 1986a, b; Campbell and

Turner, 1986; Blake and Campbell 1986).

89
E] E I. '3-1' '31! E

The geochemical data from glassy pumice samples further constrains
the inferred chemical and thermal gradients within the pre-eruptive
magma dnamber. In contrast to the whole-rock tuff samples, which are
composite mixtures of compositionally heterogeneous pumices fragments,
the pumice samples define trends that display abrupt changes in
abundance on interelement variation diagrams and apparent compositional
gaps for certain elements. Because the pumice samples from the
uppermost horizon of the ash-flow sheet span the entire range in major
and trace element composition and estimated quench temperature, these
gaps do not appear to be an artifact of inadequate sampling of pumice
fragments from the central portion of the eruptive sequence. Rather,
these gaps and abrupt changes in elemental concentrations are inferred
to reflect the changes in composition and temperature across a
liquid-liquid interface between chemically and thermally contrasting
magmas within a single chamber (Schuraytz et al., 1985). Similar
conclusions have been drawn from other pyroclastic deposits in which
heterogeneous pumice samples preserve evidence of compositional gaps
(Fridrich and Mahood, 1987).

This hypothesis of a liquid-liquid interface within the magma body
is further supported by the abrupt change in phenocryst compositions
and increase in phenocryst content at the transition from rhyolite to
quartz latite in the ash-flow sheet. Previous interpretation of this
lithologic feature (Lipman et al., 1966) concluded that the abrupt
change in crystal content did not result from downward settling of
phenocrysts from the rhyolitic magma and simple accumulation in the
erupted part of the quartz latitic magma. Because most of the chemical

variation is due to differences in groundmass composition, they

90

inferred that crystallization occurred in place within a magma body
that was chemically zoned in the liquid state. The more advanced stage
of crystallization in the lower, quartz latitic part of the magma
chamber, in spite of its higher temperature, could be explained by an
increased water content in the upper part of the magma chamber
resulting in a lowering of the liquidus temperature. However, as this
change in crystal content is more abrupt than gradational, this feature
is reinterpreted in light of recent theoretical and experimental fluid
dynamic studies.

Theoretical interpretation of the ocoirrence of mafic inclusions in
silicic lavas (Eichelberger, 1980) and laboratory models of replenished
magma chambers have illuminated a host of fluid dynamic phenomena that
can result when a relatively hot, compositionally dense liquid is
injected below a cooler, less dense liquid (Huppert and Sparks, 1980:
Huppert and Turner, 1981: mippert et. al., 1982b, 1984; McBirney et al.,
1985; Baker and McBirney, 1985).

Of particular interest is a recent experiment (Huppert et al.,
1984) in which the viscosity of the cooler and compositionally less
dense upper layer was considerably greater than that of the hotter and
denser layer below. An immediate effect of this thermally unstable
situation is the growth of crystals in the lower layer at the interface
due to heat transfer to the upper layer. Crystallization in the lower
layer auses the surrounding fluid to become less dense and this less
dense fluid was released immediately and continuously from the
interface into the overlying layer with no Significant mixing.
Subsequent crystallization also occurred within the plumes that had

risen from the interface. By varying the initial conditions of

91
temperature, composition, viscosity, and configuration of the various
fluid layers, Huppert et al. (1984) have observed numerous
double-diffusive effects of relevance to magmatic processes.

It has been pointed out that the existence of compositional gaps
within pyroclastic deposits does not necessarily mean that one existed
in the parental magma chamber (Spera et al., 1986). A short eruption
hiatus or an abrupt increase or decrease in magma discharge could
produce a compositional gap in the eruptive products of a continuously
zoned magma chamber. Spera et al. (1986) maintain that it is
impossible to invert stratigraphically controlled geochemical data to
obtain in situ magmatic gradients unless one has knowledge of the
location of vents and the variation of magma discharge with time.
While it is not possible to directly ascertain the discharge rate of
the Topopah Spring magma, the oconrrence of bimodal phenocryst
compositions within pumice samples fron both early and later stages of
the eruption, the overall continuity in estimates of magmatic
tenperatures, and the absence of even a partial cooling break at the
transition from high-silica rhyolite to quartz latite support the
hypothesis of compositional gap within the magma body.

The discontinuous chemical gradients and abrupt change in
phenocryst content and composition in the Topopah Spring Member are
consistent with a model in which a distinct liquid-liquid interface
separated relatively high temperature, phenocryst-rich quartz latite
from overlying lower temperature, phenocryst-poor high-silica rhyolite
in a single magma chamber. The geochemical data from this ash-flow
Sheet should provide useful boundary conditions for the evaluation of

double-diffusive phenomena in a particular geologic system.

CONCLUSIONS

The magmatic gradients inferred from chemical analyses and
estimated quench temperatures of glassy pumice samples and phenocrysts
from the Topopah Spring Member indicate that the transition from
high-silica rhyolitic to quartz latitic magma within the chamber was
abrupt, rather than gradational, with a distinct liquid-liquid
interface separating the two contrasting magmas. Concomitant with
eruption, this interface was disrupted, causing magma of contrasting
composition and temperature to erupt simultaneously. Although limited
mixing occurred as a result of a convergent flow regime, the duration
of the eruption interval was not sufficient to exhaust the high-silica
rhyolitic magma nor to produce a completely homogeneous magma. This is
supported by the chemical and textural heterogeneities observed both
within and among pumice samples throughout the ash-flow sheet, and
implies that the Topopah Spring Member does not reflect a "simple"
inverse stratigraphy of the chemical zonation of magma in the source
chamber. Similar heterogeneities observed within other ash-flow sheets
emphasize the importance of the appropriate choice of scale for

sampling, when evaluating dynamic petrologic processes.

92

APPENDIX

93

Table 3. Micrcprobe Analyses of Ilmenite and Magrnetite.
Field No. T102 Cr203 111203 Fe203 FeO M30 Mno Total USP ILM
BB9-IWR
0.87 0.00 0.46 64.50 27.91 0.11 2.76 96.61 0.024
7.13 0.02 1.15 51.53 33.56 0.81 1.80 95.99 0.207
9.53 0.01 2.35 46.19 34.57 2.11 1.23 95.99 0.280
8.43 0.00 2.63 47.98 33.56 2.19 1.12 95.92 0.249
* 7.23 0.01 1.94 50.91 32.85 1.60 1.56 96.09 0.210
44.81 0.00 0.56 13.26 34.53 2.14 1.93 97.23 0.862
41.17 0.00 0.50 21.07 29.91 2.75 2.18 97.58 0.778
42.68 0.00 0.53 15.04 33.87 1.01 2.68 95.81 0.842
37.50 0.00 0.35 27.75 27.58 2.30 2.02 97.50 0.709
* 42.33 0.00 0.50 17.91 32.11 2.13 2.13 97.11 0.813
BBS-1A
1.19 0.03 0.51 63.11 27.98 0.12 2.68 95.62 0.033
0.11 0.05 0.24 65.37 25.57 0.06 4.07 95.47 0.003
10.15 0.04 1.46 44.83 37.27 0.37 1.52 95.64 0.310
* 3.16 0.04 0.68 59.11 29.70 0.17 2.74 95.59 0.090
* 35.53 0.01 1.06 29.79 26.44 1.59 2.64 97.07 0.684
BB9-1C
7.42 0.07 1.79 50.91 33.76 1.54 1.02 96.51 0.217
10.36 0.04 2.35 44.91 35.84 1.97 1.14 96.61 0.306
8.36 0.02 1.50 49.16 34.16 1.26 1.79 96.26 0.242
8.56 0.00 2.00 48.13 34.43 1.72 0.95 95.79 0.253
9.43 0.03 1.79 46.87 34.85 1.64 1.53 96.14 0.274
9.46 0.01 2.40 45.66 34.57 2.05 1.02 95.17 0.283
* 8.79 0.03 1.88 48.02 34.56 1.62 1.29 96.19 0.257
41.33 0.02 0.28 19.72 30.96 2.38 1.94 96.63 0.793
34.20 0.03 0.61 32.20 25.49 1.38 2.77 96.68 0.659
41.98 0.02 0.34 18.98 31.46 2.41 1.97 97.16 0.801
37.84 0.02 0.41 26.70 27.29 2.56 2.15 96.97 0.717
* 39.47 0.02 0.39 23.32 29.33 2.23 2.16 96.92 0.755
BBS-5C
12.09 0.04 1.52 42.17 37.21 1.78 1.41 96.22 0.350
9.49 0.03 1.96 47.13 34.22 2.25 1.42 96.49 0.270
6.58 0.03 1.71 52.05 31.31 2.14 1.33 95.16 0.186
8.57 0.04 1.37 49.53 32.98 2.41 1.39 96.29 0.235
* 9.66 0.03 1.68 46.90 34.41 2.16 1.40 96.24 0.274
32.72 0.02 0.35 37.53 23.45 2.43 1.62 98.12 0.609
32.10 0.00 0.33 37.50 23.63 1.99 1.67 97.22 0.608
32.41 0.01 0.34 37.51 23.54 2.21 1.64 97.67 0.608
29.07 0.01 0.37 44.79 18.70 3.06 1.96 97.96 0.523
* 30.74 0.01 0.35 41.16 21.11 2.64 1.80 97.81 0.566
BBQ-1C
6.81 0.02 1.81 52.48 31.98 2.07 1.45 96.62 0.191
9.26 0.02 1.75 47.69 34.28 2.07 1.37 96.44 0.263
9.53 0.02 1.40 47.63 35.13 1.90 1.03 96.64 0.271
8.56 0.04 1.12 49.48 34.81 1.53 0.92 96.46 0.245
* 8.48 0.02 1.48 49.43 34.05 1.85 1.18 96.49 0.241

*nble fraction of ilmenite (IIM) arnd ulvospinnel (USP) calculated according

to the method of Stormer (1983).

for estimated telperature and oxygen fugacity determinations.

Asterisksindicatethemeanvaluesused

Field.No.

BB9-1C (cont’d.

BBB-15WR

BBB-ZSWR

*

BB8-320WR

fi% “f3
)
40.33 0.04
41.39 0.05
47.18 0.02
36.49 0.04
43.46 0.05
41.50 0.04
6.17 0.05
5.27 0.05
5.33 0.05
4.40 0.03
5.52 0.03
5.17 0.05
4.92 0.06
4.95 0.02
5.23 0.04
50.44 0.02
41.89 0.00
42.78 0.00
40.19 0.00
41.50 0.00
43.22 0.00
41.39 0.00
40.39 0.00
41.84 0.00
42.26 0.00
41.84 0.00
1.68 0.02
1.71 0.01
3.46 0.02
2.84 0.01
2.85 0.02
6.36 0.02
3.14 0.00
1.96 0.00
3.15 0.01
42.82 0.01
38.59 0.02
38.53 0.01
33.51 0.01
37.77 0.00
41.21 0.01
40.88 0.01
38.97 0.01
7.72 0.01
5.98 0.00

Table 3 (cont'd.) .

C>C>C>C>C>C>C>CDC>F>F>h*k)h‘h)hih‘h‘hih'
35583E38683858838888

OOOOOOOOt-‘HHHHHHHO
NNNNQ NHNU Old->00)
\leUOGU'Ibi-‘QHSOQOOD

“‘1"
$2

94

FED

31.42
31.73
36.67
26.32
34.46
31.68

32.95
32.20
33.08
32.02
32.83
32.32
32.82
32.28
32.57
31.23
30.64
29.86
28.12
31.22
30.51
29.72
29.52
30.34
30.80
30.25

31.12
30.21
29.17
32.01
28.49
32.40
32.65
29.90
30.91
32.49
22.43
27.19
23.44
28.27
29.12
29.80
27.56

36.48
33.85

8

hik‘hihlh‘h‘

I O O . . . . . . .
38383§§8£85838388828 533383

NNNNNNNwNNmHHHHHi-‘HNH

\lmflum

t0 \Om-FHNU'IQ-FH mosmo
oumuummuowog

0.0
LON
ubUl

NM
mos
uH

........ ........
O OU'Ii-‘UbUIUIU 00 \li-‘NH

wUOiN-hu-FUHHOHNONOO

”2"
88

Total

96.44
97.82
97.19
97.06
95.26
97.08

100.05
101.16
101.19
100.58
101.13
100.81
102.00
100.54
100.95
101.37
100.87
101.33
101.29
100.30
102.09
100.24
100.67
100.15
101.24
100.87

96.26
97.14
97.32
97.05
95.27
98.89
96.15
96.78
97.01
98.03
100.02
97.96
97.12
98.18
98.71
97.08
98.25

100.20
99.53

USP

0.169
0.142
0.148
0.122
0.151
0.142
0.135
0.137
0.143

0.051
0.050
0.094
0.087
0.079
0.174
0.098
0.058
0.091

0.226
0.170

IUK

0.782
0.789
0.905
0.690
0.856
0.796

0.898
0.765
0.772
0.721
0.768
0.776
0.758
0.736
0.768
0.769
0.763

0.815
0.675
0.721
0.635
0.714
0.776
0.779
0.730

Field.Nb.
BBB-320WR

*
*

BBB-ZOOWR

.822.
7.94

7.21
48.11

10.20
9.56
8.89
9.94
9.93
9.94
9.39

10.05
7.98
9.69

48.53

47.76

45.81

47.97

C3203

’d.)

0.01
0.01
0.00

.00....0000
OOOOOOOOOOOOEEBSBS

OOOOOOOOOO OOOOOOOOOOOOOOOOOO
00. 000000000 00000
hih’hih‘h‘h‘h‘hlulhlhlh)

8888888888 8888888888

OOOOOPOOOO

223000

NGNUI

Table 3 (cont’d.) .

J?
JP

. . . . O . . . . . . . 0°.HH
Hons:
col-I

8885fi88388 588888888383333888

8fi88688882

opooon—aoon—u—o oooooon—aoop OOOOOOOOHHHHHHHHHH

HI—‘t—‘HH
85883

38203

51.14
53.10
8.87

48.36
49.80
49.80
48.50
47.86
48.67
49.34
48.44
50.21
48.88
6.00
8.07
11.26
7.38
7.62
7.05
7.18
7.86

59.07
54.78
62.42
55.67
56.61
10.91

7.56

8.53
11.17

9.67

54.05
52.98
54.27
53.93
53.78

8.14
11.89
12.66

9.19
10.37

53.51
53.56
53.82
52.61
53.48

95

Feo .mgo .mno
36.19 0.24 1.86
35.51 0.27 1.94
38.67 0.78 3.16
38.92 0.26 1.88
38.36 0.18 1.90
37.17 0.01 2.06
38.09 0.27 2.17
38.15 0.03 2.24
38.58 0.03 2.15
38.07 0.03 1.92
38.78 0.08 2.12
35.04 0.10 2.89
38.17 0.12 2.08
37.03 0.11 6.33
34.49 0.11 8.16
37.54 0.19 3.27
38.41 0.19 4.33
37.79 0.13 5.24
36.96 0.13 6.16
34.78 0.13 8.00
36.76 0.14 5.85
32.22 0.54 0.72
33.83 0.01 1.39
31.36 0.00 1.15
33.46 0.17 1.37
33.18 0.14 1.27
36.70 0.42 4.60
39.45 0.50 3.18
38.75 0.42 3.84
35.58 0.66 5.41
37.46 0.51 4.35
33.93 0.52 2.10
33.58 0.68 2.33
33.83 0.65 2.42
33.93 0.57 2.24
33.81 0.61 2.29
37.59 1.04 4.05
34.93 1.31 4.53
34.40 1.33 4.70
37.66 1.07 3.52
36.25 1.18 4.15
33.17 0.50 2.39
33.21 0.57 2.55
33.63 0.64 2.45
33.26 0.52 2.32
33.33 0.56 2.44

Total

99.08
99.59
99.69

101.32
101.23
99.19
100.50
99.76
100.87
100.14
101.17
97.94
100.47
98.10
98.68
98.37
98.36
99.05
98.73
98.13
98.51

97.04
96.44
97.93
96.92
96.89
99.57
99.31
99.86
99.85
99.66

98.29
97.61
99.02
98.48
98.35
99.43
99.26
99.30
99.52
99.39

97.28
97.59
98.44
96.56
97.59

USP

0.235
0.210

0.295
0.275
0.260
0.287
0.291
0.288
0.274
0.292
0.235
0.281

0.111
0.166
0.063
0.155
0.142

0.188
0.197
0.190
0.191
0.192

0.184
0.188
0.191
0.193
0.188

INK

0.911

0.937
0.914
0.886
0.925
0.922
0.927
0.923
0.918

0.889
0.924
0.914
0.885
0.902

0.917
0.877
0.869
0.907
0.894

96

Table 3 (cont'd.) .

Field No. Ti cr’ .Al 88:) ink) 1013 'Dotal 'USP ILM
888-858 (cont’ .) 203 203 Fe203
49.02 0.00 0.10 8.83 38.00 1.18 3.93 101.05 0.912
45.19 0.00 0.13 14.72 33.90 1.37 4.24 99.56 0.849
49.54 0.05 0.11 6.15 39.15 0.91 3.73 99.64 0.938
47.24 0.02 0.06 11.49 35.73 1.21 4.54 100.28 0.883
46.01 0.01 0.21 12.23 34.06 1.33 4.88 98.74 0.872
* 47.58 0.02 0.12 10.31 36.37 1.19 4.24 99.83 0.895
888-20
7.67 0.01 1.14 50.79 34.53 0.54 1.94 96.62 0.224
9.62 0.02 1.10 48.19 36.85 0.43 2.12 98.33 0.277
11.20 0.00 1.00 42.86 38.57 0.00 1.54 95.16 0.342
11.28 0.02 1.18 38.45 0.00 2.07 96.15 0.341
9.76 0.01 1.12 36.88 0.28 1.97 96.75 0.289
47.46 0.06 0.03 35.77 0.62 5.73 99.12 0.902
49.66 0.05 0.09 39.13 0.76 4.12 95.19 0.985
48.60 0.05 0.07 35.58 1.05 6.17 98.82 0.923
49.66 0.04 0.14 38.39 1.03 4.37 97.35 0.961
49.79 0.04 0.08 39.26 0.88 3.90 97.87 0.960
49.27 0.05 0.09 37.91 0.92 4.70 97.76 0.950
7.59 0.01 1.02 34.31 0.71 2.44 98.69 0.211
6.85 0.00 0.85 32.67 0.83 2.99 98.11 0.186
7.01 0.02 0.84 32.46 0.71 3.19 97.01 0.193
7.31 0.01 0.94 33.33 0.72 3.18 98.87 0.199
7.32 0.02 0.98 33.06 0.72 3.21 98.07 0.201
7.12 0.02 1.01 33.58 0.73 2.43 97.81 0.199
7.77 0.00 0.97 34.32 0.71 2.55 98.59 0.216
7.43 0.04 0.93 33.83 0.71 2.65 98.36 0.206
7.33 0.01 0.96 33.59 0.73 2.74 98.27 0.203
48.38 0.01 0.05 37.97 0.95 3.79 96.66 0.943
47.47 0.01 0.05 34.50 1.33 5.74 96.53 0.920
46.80 0.00 0.05 34.84 1.35 4.78 99.33 0.881
47.91 0.00 0.03 35.31 0.63 6.57 97.57 0.924
49.61 0.00 0.00 43.06 0.00 1.53 95.43 0.988
46.43 0.00 0.07 33.29 1.26 6.14 100.63 0.860
46.27 0.00 0.07 32.75 1.52 6.07 100.11 0.859
45.10 0.02 0.05 28.68 1.82 8.52 99.77 0.830
45.10 0.04 0.09 30.56 1.24 7.69 99.18 0.844
44.61 0.03 0.04 31.52 1.38 6.06 98.14 0.845
46.64 0.01 0.05 33.96 1.25 5.68 98.58 0.884
BBB-IOWR
10.75 0.02 1.32 37.32 0.37 2.03 95.72 0.323
9.06 0.03 1.10 35.49 0.42 2.60 97.13 0.261
8.83 0.02 1.05 35.54 0.48 2.07 96.59 0.258
9.63 0.02 1.17 36.17 0.42 2.26 96.47 0.283
51.17 0.03 0.02 39.50 1.15 4.41 96.90 0.993
45.57 0.05 0.06 33.04 1.39 5.39 97.34 0.874
49.82 0.01 0.06 38.27 0.94 4.79 95.70 0.981
48.02 0.04 0.06 37.55 0.59 4.52 97.28 0.932
47.81 0.02 0.07 36.14 1.11 4.81 97.48 0.921
48.15 0.03 0.06 36.46 1.08 4.85 96.95 0.933

97

Table 3 (cont’d.) .

Field.No. n10? 0:203 A1203 88203 Fee 890 Mho 'Total USP run
888-38
7.52 0.02 0.89 51.34 34.11 0.51 2.21 96.60 0.216
7.50 0.00 0.88 51.03 33.54 0.60 2.43 95.98 0.214
* 7.51 0.01 0.88 51.18 33.83 0.55 2.32 96.28 0.215
47.61 0.04 0.02 6.84 36.18 0.51 5.65 96.86 0.927
47.60 0.02 0.10 8.51 36.23 1.33 4.15 97.94 0.911
45.95 0.01 0.06 12.20 33.29 0.98 6.20 98.69 0.871
47.14 0.00 0.07 7.93 35.63 1.16 4.63 96.56 0.916
44.44 0.00 0.06 11.68 34.11 0.94 4.12 95.35 0.875
47.49 0.00 0.03 7.10 35.95 1.22 4.52 96.31 0.925
46.59 0.00 0.07 9.88 34.99 1.12 4.85 97.50 0.896
46.57 0.00 0.08 11.29 33.23 1.55 5.81 98.53 0.880
45.98 0.00 0.05 11.48 33.59 1.20 5.55 97.85 0.878
47.48 0.00 0.12 7.92 36.39 0.63 5.12 97.65 0.917
46.21 0.04 0.08 12.45 32.85 1.78 5.46 98.87 0.868
48.63 0.02 0.09 5.54 37.12 1.19 4.43 97.03 0.942
* 46.95 0.01 0.07 9.38 35.13 1.17 4.94 97.65 0.901
888-1
10.21 0.02 1.09 46.52 36.99 0.57 2.04 97.44 0.296
9.79 0.03 1.04 46.81 36.17 0.69 1.99 96.52 0.284
10.52 0.06 0.89 45.27 37.30 0.43 1.85 96.33 0.309
* 10.11 0.04 1.00 46.23 36.70 0.58 1.95 96.61 0.295
48.52 0.02 0.07 7.91 35.87 1.18 5.59 99.15 0.918
48.35 0.01 0.07 6.61 37.32 0.66 4.92 97.94 0.931
48.12 0.01 0.08 8.25 38.00 0.93 3.57 98.96 0.916
49.43 0.01 0.12 4.72 38.98 1.04 3.57 97.87 0.951
47.88 0.01 0.05 8.91 35.40 1.18 5.48 98.91 0.907
* 48.45 0.01 0.08 7.31 37.32 0.98 4.44 98.59 0.925
CP3-2A
12.37 0.03 1.01 41.01 39.28 0.36 1.49 95.55 0.373
13.77 0.06 0.65 39.43 40.60 0.75 1.04 96.30 0.404
12.33 0.04 0.75 42.96 38.93 0.83 1.62 97.46 0.353
8.85 0.02 1.38 48.08 35.19 0.51 2.40 96.43 0.260
9.42 0.02 1.64 46.47 33.18 1.30 3.47 95.50 0.267
* 11.29 0.03 1.10 43.51 37.61 0.62 1.93 96.09 0.333
* 33.74 0.05 0.17 33.49 24.15 1.36 3.72 96.68 0.642
CPS-28
8.95 0.00 2.16 47.97 34.06 1.88 1.77 96.79 0.258
10.07 0.00 2.10 45.46 34.89 1.88 1.78 96.17 0.293
9.67 0.00 1.85 46.77 35.11 1.64 1.68 96.72 0.279
9.05 0.00 1.95 47.46 34.63 1.68 1.36 96.13 0.265
9.10 0.01 2.24 47.89 33.76 2.18 1.83 97.01 0.258
11.04 0.00 2.00 43.84 36.66 1.55 1.54 96.63 0.325
8.75 0.00 2.42 48.08 33.69 1.97 1.85 96.76 0.253
* 9.49 0.00 2.10 46.84 34.65 1.83 1.69 96.59 0.275
41.82 0.00 0.33 18.30 30.82 2.86 1.67 95.79 0.805
41.92 0.00 0.32 19.22 30.08 3.36 1.61 96.51 0.796
41.38 0.04 0.38 20.36 30.45 2.96 1.47 97.04 0.786
38.37 0.00 0.35 24.99 27.85 2.88 1.50 95.94 0.734
42.51 0.00 0.31 17.28 31.19 3.01 1.65 95.95 0.816
37.82 0.02 0.31 27.53 26.55 3.32 1.52 97.07 0.708
* 41.17 0.00 0.33 20.03 30.00 3.03 1.60 96.16 0.787

98

Table 3 (cont’d.) .

Field.No. 1102 0:203 .A1203 88203 880 mgo Mho Total USP run
CP3-1A.
10.62 0.00 1.17 44.36 37.81 0.27 1.57 95.81 0.321
10.88 0.00 1.03 43.88 37.75 0.31 1.71 95.57 0.326
8.11 0.00 0.80 50.10 35.61 0.20 1.70 96.52 0.239
12.02 0.00 0.98 42.18 38.61 0.33 2.06 96.19 0.356
10.88 0.01 0.98 44.03 37.87 0.31 1.63 95.71 0.326
7.49 0.00 1.00 50.83 34.80 0.35 1.60 96.06 0.222
9.89 0.00 0.94 46.44 36.53 0.49 1.91 96.20 0.290
6.49 0.00 0.77 53.35 34.49 0.28 1.21 96.60 0.191
* 9.26 0.00 0.96 47.43 36.47 0.32 1.61 96.04 0.275
50.79 0.00 0.14 2.17 39.24 1.53 3.66 97.53 0.977
47.63 0.00 0.07 9.06 37.89 1.03 3.07 98.75 0.908
47.61 0.00 0.30 5.52 38.82 0.78 2.57 95.60 0.943
49.65 0.01 0.08 2.32 41.24 0.78 1.99 96.07 0.976
39.63 0.00 0.15 23.35 29.92 1.11 3.69 97.85 0.757
50.28 0.00 0.15 0.83 38.65 1.01 4.70 95.62 0.991
* 47.85 0.00 0.16 6.39 38.23 0.97 3.03 96.63 0.934
CPB-lB
9.92 0.01 1.08 46.69 37.28 0.37 1.65 97.00 0.293
11.53 0.01 1.19 43.70 38.10 0.70 1.87 97.10 «0.337
8.80 0.01 1.26 47.94 35.74 0.45 1.72 95.92 0.263
10.70 0.01 1.17 45.87 38.34 0.40 1.64 98.13 0.314
10.15 0.01 1.14 45.33 37.06 0.40 1.66 95.75 0.304
11.28 0.00 1.29 44.07 38.63 0.38 1.69 97.35 0.335
12.44 0.00 1.29 40.68 39.27 0.36 1.65 95.70 0.377
10.94 0.13 1.33 43.99 38.08 0.41 1.63 96.51 0.330
10.97 0.00 1.53 44.62 38.69 0.33 1.58 97.72 0.329
* 10.72 0.02 1.25 44.90 37.90 0.43 1.68 96.90 0.319
48.65 0.01 0.18 5.21 39.21 0.96 2.79 97.01 0.946
50.05 0.01 0.23 3.05 40.87 0.80 2.68 97.69 0.969
50.01 0.00 0.16 1.84 40.87 0.89 2.48 96.25 0.981
49.71 0.02 0.19 3.34 41.75 0.46 2.10 97.57 0.966
* 49.39 0.01 0.18 3.68 40.28 0.85 2.59 96.98 0.962
CP3-10
9.86 0.04 1.75 46.80 35.42 1.55 1.83 97.25 0.283
9.74 0.02 1.76 46.51 34.84 1.72 1.76 96.35 0.280
9.87 0.01 1.84 46.85 35.45 1.62 1.77 97.40 0.283
10.15 0.02 1.77 47.23 35.87 1.75 1.75 98.53 0.286
9.76 0.02 1.76 46.97 34.81 1.79 1.91 97.02 0.277
9.94 0.01 1.72 46.64 35.57 1.53 1.76 97.16 0.286
9.56 0.02 1.74 46.95 34.82 1.65 1.77 96.50 0.275
10.00 0.04 1.78 46.20 35.41 1.63 1.71 96.77 0.289
* 9.85 0.02 1.76 46.77 35.26 1.65 1.78 97.09 0.282
41.59 0.02 0.21 19.30 31.35 2.30 1.93 96.69 0.798
45.07 0.01 0.19 13.73 32.42 3.18 2.41 97.01 0.854
43.04 0.04 0.16 16.14 32.38 2.48 1.88 96.12 0.830
44.48 0.00 0.19 13.22 33.16 2.62 2.14 95.82 0.860
42.51 0.03 0.18 17.22 31.37 2.58 2.23 96.11 0.817
43.27 0.02 0.18 16.26 32.00 2.69 2.09 96.51 0.828
43.13 0.02 0.25 15.52 32.17 2.56 2.03 95.68 0.835
41.53 0.03 0.23 19.10 30.48 2.64 2.13 96.14 0.797
'* 43.14 0.02 0.20 16.15 31.96 2.64 2.10 96.21 0.829

Field No.
CP4-ZOEWR

CP4-60WR

CPI-3WR

CP1-3A

T102

5.61
6.12
5.87
5.87
40.53
40.18
44.67

.8
8888888888 8888888888 8

88888888 8888888888888888888
C>C>P‘P‘h'h‘hik‘ C>C>C>C>s>c>c>C>C>C>P*F‘P*F‘P'F‘F‘h‘

OOOOOOOO OOOOOOOOOOOOOOOPOOO 0000000000 0000000000

Table 3 (cont’d.) .

B
an
M0

C>C>C>C>C>S>F‘F‘F‘P‘
5558558888

1.37
1.14
0.93
1.18
1.16
0.03
0.03
0.01
0.02
0.02

1.17

858858888888888858

. . .
85858858

99

F%%

57.47
55.91
56.76
56.72
24.88
24.06
15.06
20.93
24.08
21.93

50.35
54.07
53.16
51.67
52.30
17.02
19.17
11.95
13.59
15.30

48.01
44.27
44.16
44.56
44.86
43.72
43.14
47.08
44.81
6.93
8.48
7.49
8.10
8.18
8.66
7.37
8.53
8.45
7.99

44.61
44.86
44.61
44.10
43.73
44.35

7.78

8.51

no no) normal

32.59
32.95
32.81
32.79
28.30
28.50
33.08
30.49
29.15
29.82

36.35
34.56
34.25
35.82
35.25
36.02
33.53
37.46
36.54
35.93

37.70
38.00
37.76
38.65
37.84
38.01
38.62
38.26
38.09
35.47
37.95
38.58
38.59
38.92
39.04
40.22
38.42
38.56
38.40

37.84
37.77
37.67
37.40
37.71
37.67
38.79
38.33

OOOOOOOOOO
........ .....

mowmoqmouor-unuuowomun 2%33‘0’155853

mumqoopmoouslunuusssqqe-

OOOOOOOO OHOOOE—‘OOHOOOOOOOOOO

QQDU'IUUbU
OO‘HO‘QNOU‘I

2.53
1.86
2.31
2.23
3.45
3.05
4.36
3.44
2.70
3.38

hlhlhlhlhlrlhlhahapa
8885888558

. .
OGQQQ

Cumuommmnowtoqowooofigg

OHNGO‘QNON

hUkuuUUhUQNNUHi-‘HNHH

hiklkihif‘hih‘h‘
tslo~q¢n~dnonoeo
lo~q.><ono<nla

101.25
100.16
100.07
100.50

99.96
98.53
98.79
99.22
99.78
99.21

98.11
98.20
97.36
98.69
98.08
99.87
99.00
98.58
98.49
98.94

99.35
97.53
97.57
97.82
96.91
96.18
99.65
99.52
97.95
99.36

100.84
100.51
100.13
101.72
101.49
101.59
101.02
100.57
100.80

95.59
96.94
96.48
95.31
96.16
96.12
98.43
98.56

USP

0.152
0.168
0.159
0.160

0.243
0.187
0.195
0.227
0.213

0.288
0.331
0.331
0.331
0.319
0.332
0.354
0.303
0.325

0.317
0.319
0.320
0.321
0.331
0.322

IUM

0.742
0.748
0.843
0.783
0.751
0.772

0.831
0.806
0.880
0.863
0.846

0.927
0.915
0.925
0.919
0.919
0.914
0.928
0.915
0.916
0.920

0.921
0.914

100

Table 3 (cont'd.) .

Field.No. 'r Cr A1 880 M80 Mho Total USP ILM
wk“ (“11332) 203 203 F9203
48.46 0.00 0.10 8.25 38.84 0.83 3.22 99.70 0.917
47.64 0.00 0.30 8.71 38.35 0.75 3.11 98.86 0.912
47.55 0.01 0.10 9.45 37.61 0.88 3.54 99.14 0.904
47.50 0.00 0.08 8.26 38.10 0.78 3.18 97.91 0.916
46.86 0.00 0.08 9.84 36.26 1.25 3.60 97.90 0.898
47.19 0.00 0.09 8.43 37.90 0.81 3.05 97.47 0.914
47.07 0.00 0.09 8.79 37.87 0.75 3.08 97.65 0.910
* 47.59 0.00 0.12 8.67 38.02 0.85 3.22 98.47 0.912
cpl-28
12.03 0.00 0.92 42.40 38.84 0.43 1.73 96.35 0.355
9.93 0.01 0.83 46.19 36.84 0.33 1.78 95.91 0.293
11.24 0.00 1.01 43.45 38.00 0.38 1.77 95.85 0.335
10.89 0.02 0.97 44.34 37.87 0.38 1.66 96.13 0.323
11.59 0.00 1.01 44.17 36.75 1.67 1.68 96.87 0.325
10.14 0.01 1.04 46.11 36.98 0.60 1.65 96.53 0.298
10.54 0.00 0.90 44.72 36.81 0.41 2.14 95.52 0.311
* 10.63 0.01 0.96 45.04 37.32 0.55 1.74 96.25 0.312
47.51 0.01 0.05 9.66 37.95 0.91 3.11 99.20 0.903
47.77 0.01 0.02 8.94 37.99 0.93 3.27 98.93 0.909
47.89 0.01 0.04 7.80 38.38 0.87 3.09 98.08 0.921
48.40 0.00 0.31 8.73 37.99 1.25 3.26 99.94 0.912
47.51 0.02 0.02 9.21 37.67 1.01 3.21 98.65 0.906
47.60 0.01 0.18 8.41 37.04 0.93 4.05 98.22 0.913
48.70 0.02 0.04 8.28 38.50 1.12 3.26 99.92 0.917
47.57 0.02 0.01 8.66 37.90 0.90 3.23 98.29 0.912
* 47.90 0.01 0.08 8.68 37.96 0.99 3.31 98.93 0.912
CPl-lG
10.47 0.01 1.13 44.57 37.43 0.39 1.54 95.54 0.315
10.77 0.00 1.11 44.36 37.82 0.32 1.70 96.07 0.322
10.90 0.01 1.10 44.12 37.95 0.37 1.60 96.05 0.326
10.63 0.01 1.11 44.52 37.42 0.50 1.60 95.79 0.317
10.88 0.03 1.30 43.31 37.58 0.45 1.58 95.13 0.331
11.46 0.02 1.08 42.54 38.20 0.32 1.73 95.35 0.346
12.18 0.01 1.21 41.70 39.10 0.42 1.66 96.28 0.365
11.05 0.00 1.14 43.19 37.85 0.42 1.49 95.14 0.334
* 10.99 0.01 1.13 43.74 37.89 0.40 1.62 95.78 0.330
48.54 0.01 0.02 8.38 39.02 0.88 3.02 99.87 0.916
49.56 0.00 0.06 6.52 39.60 0.93 3.27 99.93 0.935
48.75 0.00 0.07 7.68 39.18 0.86 3.09 99.63 0.923
49.31 0.00 0.06 7.44 39.56 0.88 3.17 100.43 0.926
48.38 0.01 0.07 9.47 38.19 1.28 3.00 100.40 0.905
48.03 0.01 0.09 8.63 38.43 0.89 3.13 99.21 0.913
49.55 0.01 0.11 7.82 39.88 0.90 3.03 101.30 0.923
48.02 0.03 0.11 8.43 38.51 0.87 3.08 99.06 0.915
48.86 0.02 0.10 7.55 39.32 0.87 3.03 99.75 0.924
* 48.81 0.01 0.07 8.00 39.12 0.93 3.08 100.01 0.920
CPl-AFB
10.51 0.01 1.14 44.51 37.10 0.38 1.93 95.58 0.314
9.54 0.00 1.12 46.08 35.67 0.51 2.07 95.00 0.284
* 10.03 0.01 1.13 45.30 36.39 0.45 2.00 95.31 0.299

Field.Nc. 'ri

cmem(mm'4

CPloAFWR

47.61
47.69
47.35
47.44
46.62
47.62
47.99
47.71
47.72
48.50
47.65

9.55
10.67
11.14
10.58
10.69
10.92
10.65
10.48
48.17
47.58
44.66
48.64
47.04
47.81

u H
moomqoooo
aupm ace
mwangmN

C§%

0.02
0.03

oopoooooo
888888888

OOOOOOOOPOOOOOOOO
OOOOOOOOOOOOOOOOO
NHUUNHHNUNNNUNUN‘J

cncngnsnsngntnsngnsncncncnc>c><3c>c>c>
8888888888888888888

Table 3 (cont’d.) .

B
an
000

coopooooooo
88888888888

oooooooopHHOl-HHHH

. . . . . . . . .
8888558888888888888 88588808888888888

ooooooooooowwwwwwww

101

F%%

8.07
8.71
8.62
7.82
8.86
8.78
7.73
8.16
7.89
6.45
8.11

47.81
45.84
43.36
44.53
43.98
44.37
45.48
45.45

8.64
11.04
16.21

8.85
10.15

9.98

8.87

8.17
10.17

46.74
45.41
47.35
47.23
49.87
48.46
47.20
47.25
22.18
13.33
18.63
29.25
28.65
19.59
12.43
16.21
19.14
17.94
19.16

FED

37.46
37.55
37.15
37.55
36.84
37.56
37.82
37.65
37.71
38.95
37.62

36.48
35.90
36.52
36.36
37.49
36.19
37.62
36.76
34.65
36.57
32.73
38.73
36.76
37.17
35.43
38.77
36.33

35.32
35.97
35.75
34.47
33.70
34.06
35.49
35.08
29.16
34.50
30.87
26.29
26.00
30.19
34.20
31.18
29.55
27.93
30.10

. . .
0‘0

..
momow
dHO‘ngi-‘m

pooroooo

smomosmo

. ......
ggfisgsggggmewmmmgfifl gmoomwmoguuouuumu

4534000me

HOPHOOHHPOOOOOOOO

. ...
UIGONHH

alone:unanunnnnnnnnnnisopapacnpapapapa
.

8

wuuuuuuuuwu
eeeee eeeeee
I“ fiwmlfihu mm

0.000.
O‘NU‘OQU

puouuubhoumuwuuuu
. .
UWQN ObQUI

0000000 000000000

kihlklh‘hlhlhlhihlr‘h*hih'F‘P‘F‘P‘F‘F‘

bH

97.77
98.55
97.78
97.21
96.72
98.49
98.18
98.02
97.82
97.95
97.89

98.05
98.07
95.95
96.13
95.70
95.58
97.63
97.01
99.39

100.68

99.86

100.58

98.79

100.12
100.44

99.58
99.95

97.00
96.01
97.31
97.00
95.29
96.35
96.06
96.62
95.36
96.11
96.53
97.23
96.45
96.66
96.87
95.81
95.84
96.75
96.35

USP

0.277
0.300
0.327
0.311
0.323
0.312
0.312
0.305

0.282
0.298
0.276
0.272
0.226
0.249
0.272
0.272

ILM

0.917
0.911
0.911
0.919
0.908
0.910
0.921
0.916
0.919
0.934
0.917

0.909
0.888
0.833
0.912
0.896
0.899
0.908
0.918
0.896

0.763
0.861
0.803
0.691
0.694
0.792
0.870
0.826
0.794
0.803
0.796

Field.Nb.

1W2HA

IW2-5

EW2-10

T102
8.49
8.89
8.89

10.28
9.09

3
8888888888888888888 8

0000000900000000 OPOOOOOOOOOOOOOOOOO
00 0000000 0
HHSHHHNHOH88P888

8888888888

900009000000
00

UN

Table 3 (out'dJ .

f
&

°PPPPPPPPPEEEEFEPPP
h) h“ u)h*h:h3h0ho h: as a-uu~ln:
a-g}0\5;c>~Jaau:~Ja\8:a~g3nae}~301h'0I

n:u:m:a-h-h>nzu:3.a\a\u>UIa\uuua
oomwsobasoumosomqnmm

OOOOOOOPHHHOHPHO

NU HHO\O\OU N0
ngmqququgoq

102

F%%

48.84
48.83
49.77
45.78
48.89
48.67
46.31
45.69
47.84
19.88
17.11
24.02
15.66
30.38
17.00
18.11
20.21
24.62
20.59

45.55
48.31
52.04
51.02
47.10
50.60
48.33
49.38
30.49
22.24
29.64

1.93
30.06
30.72
28.17
26.45

44.80
46.59
46.50
44.92
48.16
48.23
46.38
17.19
20.23
17.55
22.36
19.33

an by) up

34.54
34.32
34.98
35.95
34.64
34.24
35.33
36.90
35.11
30.61
32.42
29.07
32.87
25.15
32.32
31.57
30.62
29.14
30.47

36.88
34.80
32.88
32.15
35.31
32.38
34.67
33.83
26.19
29.89
25.95
40.47
26.30
25.92
26.96
27.94

36.23
34.43
36.00
35.98
35.56
33.89
35.47
32.16
30.29
31.89
29.32
30.92

0 o
UIUU‘U'IO‘

hm
NNG‘OUO‘HHUIgl-‘OHMUSQUJ:

O 0.
aunomuuouusun

a:«a«35:5:«in:5:5351papapapapapapapapa
0

NNNNHNNNHHHHHHNO
O 0 00 00
me‘UINQO \l locum N

UUNUNNNHHNNN
00000000000
qum chum lb."

1.53
1.92
1.83

000000000.
mmqqmuxno “‘3

HODPO‘UNUIQUNI

0
UIUHGNGU

bmmqwmumgwmbuuwu

hi8)&)h)?)h)h)hlh)h¢hihlhihiFifi) hiklhohahdhahapihahapa
0
u:u:hahoUIua~Jc>

DUIQO

P‘t‘f‘t‘t‘h‘f‘h‘h‘h‘h‘h‘
u:u:n.u:n:u:u1t:raua~1ua
O\GD£-JLJ\OIA

95.79
97.30
98.50
96.39
97.81
97.03
96.64
97.93
97.22
96.28
96.92
96.99
96.61
97.25
96.56
96.65
97.74
98.01
96.90

95.88
98.14
97.85
97.02
96.73
96.39
97.11
97.13
98.50
97.39
97.97
96.76
98.21
98.36
98.19
98.00

97.42
97.53
98.37
96.78
97.91
97.42
97.69
96.33
98.34
96.47
97.23
97.10

USP

0.247
0.252
0.249
0.297
0.255
0.252
0.287
0.309
0.269

0.303
0.267
0.207
0.213
0.279
0.215
0.260
0.243

0.315
0.282
0.295
0.308
0.269
0.259
0.291

IIM

0.790
0.821
0.748
0.836
0.677
0.822
0.810
0.789
0.744
0.784

0.682
0.767
0.688
0.980
0.685
0.679
0.705
0.723

0.820
0.789
0.816
0.765
0.797

103

Table 3 (cart'd.) .

Field.Nb. T10: 0:203 A1203 F9203 880 M90 mno Tbtal USP ILM
1N4-1wa
9.84 0.00 1.78 47.18 35.56 1.57 1.80 97.73 0.281
10.91 0.02 3.34 44.86 36.11 2.42 1.72 99.39 0.317
10.92 0.00 2.68 44.66 36.64 1.95 1.49 98.33 0.320
7.31 0.01 1.76 51.91 31.73 2.19 2.08 96.99 0.200
8.84 0.03 2.07 48.90 34.45 1.77 1.75 97.81 0.252
9.65 0.02 0.91 48.16 36.75 0.44 2.11 98.05 0.276
10.13 0.00 1.84 45.46 36.97 0.98 1.24 96.62 0.305
9.32 0.03 2.38 48.28 35.10 1.97 1.54 98.62 0.267
8.04 0.03 1.81 50.21 34.25 1.11 2.08 97.53 0.232
11.02 0.06 2.51 43.56 35.51 2.12 1.90 96.67 0.322
* 9.72 0.02 2.16 47.08 35.43 1.68 1.75 97.84 0.281
42.60 0.00 0.23 22.81 22.94 6.12 4.40 99.11 0.743
43.89 0.00 0.22 15.21 32.92 2.50 2.07 96.80 0.840
42.79 0.00 0.23 20.56 24.72 5.36 4.15 97.81 0.769
44.37 0.00 0.27 13.66 34.02 2.32 1.72 96.36 0.857
* 43.41 0.00 0.24 18.08 28.63 4.08 3.09 97.53 0.804
1W4-1B
6.83 0.01 1.21 52.45 33.09 0.82 2.16 96.58 0.195
8.48 0.08 1.18 49.74 34.95 0.87 1.97 97.27 0.243
6.62 0.06 1.36 52.29 32.49 0.89 2.31 96.02 0.190
7.13 0.03 1.36 52.54 33.38 0.87 2.47 97.78 0.201
7.16 0.01 1.00 52.14 34.33 0.53 1.75 96.91 0.208
* 7.24 0.04 1.22 51.84 33.64 0.80 2.13 96.91 0.207
48.94 0.02 0.07 6.24 29.98 3.27 8.10 96.62 0.928
48.55 0.00 0.09 4.22 38.19 1.39 2.95 95.39 0.956
* 48.81 0.01 0.07 5.55 32.72 2.64 6.38 96.19 0.938
1W4-5B
9.39 0.00 1.52 49.08 34.26 1.93 2.31 98.49 0.255
7.76 0.00 0.95 50.44 32.88 1.13 2.39 95.55 0.218
8.36 0.00 0.90 49.31 32.78 1.40 2.55 95.30 0.232
8.97 0.00 0.74 47.81 35.08 0.38 2.37 95.35 0.261
* 8.90 0.00 1.28 49.32 33.88 1.59 2.35 97.32 0.245
36.20 0.00 0.18 28.61 27.21 1.68 2.32 96.20 0.698
39.36 0.00 0.07 22.62 29.47 1.90 2.51 95.93 0.760
38.92 0.00 0.04 22.64 28.94 1.81 2.80 95.15 0.758
* 37.67 0.00 0.12 25.63 28.20 1.77 2.49 95.88 0.728
1W4-10wa
9.37 0.02 1.01 48.36 35.29 1.04 2.16 97.25 0.264
9.57 0.04 1.22 47.29 36.51 0.47 1.99 97.10 0.281
7.63 0.04 1.09 51.67 34.06 0.89 2.08 97.46 0.216
* 8.86 0.03 1.11 49.10 35.29 0.80 2.08 97.27 0.254
* 36.39 0.00 0.22 29.96 24.21 2.95 3.21 96.94 0.676
1N4-15wa
3.86 0.05 3.12 59.90 19.92 5.16 6.91 98.92 0.071
10.10 0.00 1.89 46.43 35.07 1.79 2.10 97.37 0.287
16.91 0.03 2.08 31.53 41.96 1.45 1.51 95.47 0.519
* 10.29 0.03 2.36 45.95 32.31 2.80 3.51 97.25 0.277
44.56 0.00 0.38 13.48 34.19 2.23 1.88 96.72 0.859
44.64 0.00 0.17 12.80 33.64 2.19 2.57 96.00 0.865
* 44.60 0.00 0.28 13.15 33.91 2.21 2.23 96.38 0.862

104

Table 3 (ocnt’dJ .

Field.Nb. 'Ti Cr Al FEO' ugo Mho Total USP run
0113-3 1m 02 2°3 2°3 Fe2°3
10.70 0.00 1.15 44.60 33.47 1.46 4.00 95.38 0.294
8.85 0.00 1.62 47.71 33.13 1.48 2.72 95.51 0.251
3.53 0.00 2.11 57.50 29.59 1.50 1.42 95.65 0.102
* 8.45 0.00 1.51 48.60 32.42 1.48 3.03 95.49 0.237
* 39.71 0.00 0.64 22.08 28.32 2.98 2.05 95.78 0.762
GUB-ZBWR
6.18 0.03 3.54 52.75 33.44 0.48 3.02 99.45 0.188
8.12 0.02 1.77 51.14 33.12 1.64 2.79 98.60 0.222
6.49 0.03 2.25 53.86 30.36 1.99 3.55 98.54 0.172
* 6.91 0.03 2.61 52.50 32.52 1.27 3.08 98.92 0.196
35.55 0.06 1.19 28.34 27.38 1.90 1.19 95.61 0.699
37.69 0.00 0.35 26.10 25.73 2.30 4.01 96.19 0.715
* 36.97 0.02 0.63 26.86 26.27 2.17 3.07 95.99 0.710
GU3-23WR
11.04 0.02 2.34 43.27 35.53 2.03 1.81 96.04 0.324
9.66 0.01 1.99 46.47 34.78 1.72 1.82 96.45 0.280
12.53 0.02 1.11 40.85 37.91 0.63 2.64 95.68 0.368
* 10.69 0.01 1.96 44.26 35.63 1.63 1.96 96.14 0.312
41.10 0.01 0.44 18.98 29.24 2.24 3.68 95.69 0.794
38.76 0.01 0.65 24.72 26.39 2.81 3.41 96.76 0.732
38.37 0.00 1.15 23.03 27.76 1.83 3.44 95.58 0.749
* 39.41 0.00 0.75 22.27 27.78 2.30 3.51 96.02 0.758
GUB-ZOWR
10.39 0.00 1.22 47.50 38.48 0.17 2.11 99.87 0.300
8.43 0.00 1.41 48.83 36.92 0.08 1.05 96.72 0.259
10.04 0.00 1.92 48.43 39.12 0.14 1.80 101.45 0.295
10.65 0.00 1.36 44.48 39.12 0.24 0.57 96.42 0.328
* 9.92 0.00 1.39 47.20 38.33 0.16 1.42 98.42 0.296
48.38 0.00 0.05 7.18 37.98 0.27 4.98 98.84 0.926
50.44 0.00 0.08 4.10 38.14 0.28 6.63 99.67 0.958
49.24 0.00 0.04 7.14 37.48 0.39 6.03 100.32 0.927
46.63 0.00 0.13 10.25 36.91 0.21 4.59 98.72 0.895
* 49.28 0.00 0.07 6.24 37.78 0.30 5.92 99.60 0.936
GU3-17WR
10.39 0.01 1.38 47.53 37.25 0.11 3.55 100.22 0.293
10.07 0.01 1.41 47.93 38.05 0.20 2.24 99.90 0.291
9.67 0.00 1.88 47.60 36.19 0.21 3.52 99.07 0.280
* 10.04 0.01 1.55 47.68 37.16 0.17 3.10 99.72 0.288
49.81 0.00 0.07 4.62 36.89 0.09 7.64 99.12 0.951
49.60 0.00 0.08 5.69 38.13 0.13 6.16 99.79 0.942
49.09 0.00 0.16 6.13 36.56 0.21 7.12 99.26 0.936
* 49.43 0.00 0.11 5.57 37.01 0.16 7.06 99.35 0.942
GUB-14WR
9.85 0.04 1.25 45.64 37.42 0.10 1.53 95.83 0.301
9.83 0.06 1.31 46.94 37.60 0.23 1.72 97.68 0.293
10.03 0.02 1.62 45.79 36.85 0.11 2.71 97.13 0.300
* 9.87 0.05 1.33 46.21 37.42 0.16 1.78 96.82 0.297
47.72 0.02 0.06 6.46 39.14 0.14 3.48 97.02 0.934
49.48 0.02 0.05 4.42 38.66 0.29 5.25 98.17 0.954

105

Table 3 (cont’d.) .

Field No. Ti Cr 0 A1 F630 1490 1810 Total USP IIM
603-14wn.(ccnm.d ) 2 3 2°3 E3203
49.05 0.00 0.06 4.58 37.89 0.13 5.91 97.62 0.952
47.74 0.06 0.08 7.39 39.44 0.15 3.18 98.04 0.925
* 48.44 0.03 0.06 5.76 38.82 0.17 4.38 97.66 0.941
603-11
8.42 0.02 1.22 50.86 36.81 0.25 1.62 99.20 0.245
10.02 0.04 1.02 47.14 37.32 0.23 2.21 97.97 0.291
8.58 0.02 1.13 50.47 36.82 0.27 1.62 98.92 0.250
* 9.02 0.02 1.11 49.45 36.98 0.25 1.81 98.65 0.262
48.93 0.00 0.11 7.61 39.03 0.83 3.45 99.95 0.924
48.44 0.02 0.20 7.60 38.23 0.80 3.85 99.14 0.923
48.42 0.01 0.25 7.54 38.51 0.77 3.61 99.12 0.923
47.99 0.01 0.16 7.89 38.45 0.85 3.15 98.50 0.920
* 48.52 0.01 0.17 7.64 38.63 0.81 3.51 99.30 0.923

95.09

1 4.31 0.60 0.14 96.18

0 4.82 0.91 1.29 95.96
96.36

94.30
95.13
94.31
95.44
96.39
95.99
94.58
95.22
.44 4.38 1.81 0.15 94.76
96.13

7.77 6.09 0.48 2.42 95.25

7.98 6.10 0.42 2.53 95.13
93.25

93.42
94.42
94.85

0.59 8.63 4.37 0.55 0.09 94.92
95.01

5 6.16 0.47 2.52 95.76
2 5.97 0.41 2.25 93.89

71 4.34 0.56
8

2

.87 4.43 0.53
70 4.36 1.15
75 4.34 0.54
72 4.55 0.60
9

9

.76 4.44 0.61
.84 4.60 0.60
.89 4.49 0.57
.82 4.29 1.78
.79 4.28 0.62
.77 4.37 1.03

8
8
8
8
8
8
8
7
7
8
8
8
8
8
8
8
1 8.47 4.13 0.62

1 8.70 4.32 0.52
3 8.68 4.41 0.61

0. 51 8.77 4.20 0.52

mmsmsws

000000000000000000000

.5
.5
.5
0.52 8.55 4.20 0.60

106

Immpflnmmwaofmmfia

23 9.92
4.52 13.84
03 13.63
19 9.65
92 9.67
41 9.63
20 9.76
90 9.83
27 9.80

4

LmLLmL
22211222222

35386
624..23

1

12631.95
53164..34..

uuunnuuwlnnnnnun

925288
.6.4..7.27.7.1...

Table 4.

4uuunnn

17326191
.257.7.1588

fi%Ah% m0 m0 m0 my 90 fig m0 momma

BBS-1A
EBB-13

96.84

00000000000000000

98108950739 4153
18nw97.~1.4..87.7. 4687

O
—I.~h~h666666’6.66666

8 3

42126727516
.“WJ63J55A6ASRW

.8888888888888
9268100184250
.al.—I.77al.88777778

O. 00......
0000000000000

0.73 8.67 8.52 0.28 1.30 98.72
0.76 8.37 7.85 0.35 1.49 96.95
0.81 8.64 7.81 0.39 1.21 99.26

0.82 8.23 6.99 0.3
0.83 8.51 7.24 0.
0.77 8.80 7.06

0. 81 8. 72
0. 94 7. 73

.88 .mmnuu1
LnLL uuuu
0

333266411 70 95 7
£336538Qw6nw 0.4hm32w3w

1nuununnlmn1.n1nuuun1u1

2mnnmwwnnmm3 maz mmmmfimm4

13.44 0.06 0.72 7.94 7.72 0.36 1.38 93.70
.9

14.30
14.38
14.80
14.02
14.06
14.51
14.12 0.05 0.75 8. 57
14.44
3 13.24
7 14.53
01L 71
814.56
214.42

.9
43
.7
42
.2

7
4444444 44444 444444
1““.1 llllllfilllllullllllu
751 11426 321 502881385
423 8295—]. 856 59.6174622
00...... 0....
656656666.4..6.6.6.6.Am56656666
33333333333333333333333

.81 0.39 1.24 97.14
.68 0.31 0.47 96.45
.09 0.30 0.77 97.01

107

Table 4 (cont’dJ
14.34
.19 14.68
.72 14.75 0.07

13
13

27
26
90

fi%AM% mo mo mo mp'go m% mo momma

889-13 (cont’d.)

36.42 14.
37.22 14.

37.04 13.

BB9-1C

Field No.

“4298854425320469945 6988
8821489129030468815 0556
6777777666767677757686756
9999999999999999999999999
2132948995 90801996 469 2
2697236250.04111574 783 3
00.0.00... .....OOOOOOOOO
0221214104 03000022201101
5265102029140500354125230
3332333332343253232333323
......OOOOOOOO

000000000000000.nwnu.nwnm0.0.0.0.nm0.

8463066035823766

6156699
al.4656dh93nw0u166002 5524..3Q~4“

5666666666656656666666656
1017395379 9993 752045041
222537.4..80~6 597.3 9nw220u28wo.8
9888887887987899888888898
41830nm683 36232013920114
78878 al.77 77857777.677777
.00.... 00.0.00... 0.00..
0000000000000000000000000
5 3

.mmo. o m omomo o

0

0.0.0. 0 0. nwnwnw0.nU.0.nmnw
WW8” 07786199758 056 3111
389mal.33950~57m 63.2. .24..0.5
4..4..4..14..3 5

M1301861216777028310 6098
2402252550845529441 3369

3 3

mMMMMMMMnM ManMM MMMMMM1

1M0 wmmawnmnfimmmummmnnnnm

MLL1.LLL11L1LLLL11LLLLLLLL
279 70957 237983622 290502
23311363fi39m1523532 62.1556
O... O...

7556664663874787745575665
3333333333333333333333333

BB9-5C

0841565197385947426
7781620627628503935
8868684766796768476
9999999999999999999
820258905 727324992
474201671_359778198
000...... 0.00.0...
101322111 110111120
64702775 8844710231
33243337 333394434
0... ......OOOOIOOO
0000000000000000000
00 38 596280315
~I.—I.78~I.~I.6~I.666676

38287

.83732

6757&
897121367640
241577623397

4311218037775265969

8878777886886877795
0000000000000000000

753 5 54 55 537
000M0m01 00 00.“.0
0.0.0.0....
00000000000nm0.0.nwnu.0.0.nu.

7554540523504947151
2882828548587928329

3MMDBMBM MwMMMnMMnnn

75523874 155 21
1564..535—I. 6“”.6AM2MWQHAU.

EM n51 mnMMMuMnMnmmM

8888888888998888888

444444444 4444

7.4.39

.L555556776556L55
3333333333333333

36.4
37.2
36.

108

Table 4 (cart’d.).
A1203 Feo M30 Cao Nazoxzo TiOZMnO BaOTotal

J

%

Si

¢-10C

Field.Nb.
BBQ-5C (cont’
1:

9 96.78
95

972286441833659
9068452643345604
O O 0..

27 2.78 96.32

0

0000000000000000000000

1
7
9

22560 292 511 84705
74646 09434 435 269 98838

66665&&&&&&&&&&&&&&&&i&&&

. 9 0.33 3.00 97.76
. 5 0.39 1.63 97.87

2 4031679845 37325 17 9
B5m2nwj85£5315 86697 50.1“7

O. 0....

8888988878887887876889988
76 8777777787 887 877778
0............OOOOOOOOOOOO
0000000000000000000000000

63 33 3 52

00 00 0 00
........-._.._.__....._..
00 00 0 00
77322056174 35011 0271 60
0.2588825nw58 B.nw4“86.9 30.86 4H9

A..4..4u4..4..

4B..l..111111.._mu.1...n.4 4B.u.1.._n.1n.1.
192 8529 12 801 17096261
485D9349M68wu842 4.57.22835

uuuunuuulnnnlnlununuunnnl
mmngmmm «zom%mu Ememxmmam
mmuuuunuuuuuuuuuluuuuunlu
a” numwwwawmmms m451955933

555 745 4 543554..64..
.333 333 3 3333 33

35.

36.

35. 4
34.6
35.2
36.9
36.2
35.9
34.7

3
3

BBS-853

93.51
95.17

.26 1.20 94.63

0.70

02 88135504
ZBHMJ3AH535R~A

4.21 0.65 0.09 95.07
3

4.48 0.60 0.13 94.50
4.33 0.49 0.10 94.98
4. 38 0.56 0.11 94.72

3. 89 0.79

4.
62
4.
4.
4.
L
4.
4.
4.
4
4
4.

9250706
687.7.85nw

88888888888888889

.61
.56
.77
.71
.67
71

.40

.66
.12

maaflmawammamma%m

cocoa-0.0.0.0....
00000000000000000

411.1.” 114m .14m
mmmmnuussmn9m9n9
%mnammwa ummwm 4%
mmmmmmnnn 152 m

5070 8 745 56411
7.34..1“2 n.1nd613dh263

nu1nnn1nuuuunnnn1
mummwvwnammnsnwnm

666.,m7 756506566766
:33 3:333

92.47

0.73 0.11 94.70

0.58 0.13 93.75

6 0.63 0.12 93.65
0.76

.50 0.28 2.82 95.51
2
.51

.36 0.67 0.12 93.96
.5
.5

46404..4..4..

109

Table 4 (cont’d.) .

36.21 12.81

Field.Nb. $103.?1203 F90 IMgO C30 ‘Na20~ KQO' T102 .MhD BaO Tbtal

Bm4m(mm
m&m

651939366433177093246395
666399619747627886813364
557754274567347645688765
999999999999999999999999

9

1 w
.......-.............—..

0 0
$5309660H695$35163566 53
6 6564654555 55655~I.7.5 —I.5
0000000.0.nm00000000.0.0.0.0.0.nu.0.
212 45 985 30 509
4..4..4..4..4..4..4..4..4444444..4..4..4..4..4..4..444
972141 68377266352 2257
96828-I. 0.4..67.857.1360~ 3229

888988898888889988899998
45434555555 52 5 5.55 5
0000... 00.00.00...

000000000000000000nw0.0.0.0.0.

.../mm”. “.7.“ .w7...110..—nw.%7....._..
00 0.nwnu. 00 00000

nmmummwmmmmmwmnwnmawmwna

cocooooooooooooooooooooo
00 0

31131m19m4122460591134 0
$5982 39 d..~l..l.7.0u7.834“8533 7.

322222223222112022233232
222222222222222222222222
56 106365672 55399937

unnnnuuununnuuununnnnunu

09 9825 66174645436990
6&4 .&6.9.0w7. .7.7.Qu89m10u319mld..7.5

BB8-ISB

04769390M2113322429
84749480 3815670943
6751575563563064476
9999999999999999999
42 9
22 0
...._..._........_.
00 0
7745 64557 5

nvnwnmnmnvnvnvnvnvnvnununvnunununvnvn.

5nM_/.b.a.anmmwnunu.qnqo;g.9.016.3.q
.4 .4.3,o./ .u.4.4.1,o_b.4.2.d.5
4.4.4.4.4.4.4.1.4.1.4.4.4.9.4.4.4.4.1.

mu aamwnmmnmmafls an mo
9888889887998598898
79808209 415205 679
54AJA5£A.J£5£JA.JAA
0000000000000000000
mammmm oumm mnmmn .m
00000000000000000 0
mnmmmnws «:wmm nwmm

99009muu09997n n.9nu.

mmans mmmw9

2265047
nwd..50.10~3

61nm0.2316n.2210.0.2628

1222222 222122121
9580320 65363520M4
6387268 J8A3Q~A£1
nu unnnmnlunuaunmnl
.mmnammamgn$u.&mmmw
8664555888555965768
333333333333333333

110

Table 4 (ca’tt'd.) .

fi%Ah: no mo mo mi 9: fi% mo momma

Field NO.
BBB-5

7mm11n66 m

3883554....14"
999999999999989999

uanx gunmmwnmmmn

0.nm0.nwo.nu.0.nw0.nu.nwo.o.o.o.ooo
979121

$fi455555m8w
0.0.0.0.0.nmnwo.nmo.o.0.0.nwnw

63
2.].
34..

4. 4O

6
.7.
.5

9.13
6.34
3.24
6.24
3.43

787672
.9.54..55

.nw
082608127238308
8355.

314..834..52534..

1:5$8 9mmmnmmnmw

789888878789888888

5%uaum5ww 5&9

000000000000000000

mwmmmmmu um 38mmmn

so... .0. -
000000.00 0.0. mmmnwnmo.

Gama/22 069 6 594
5A3 9.27. 989
89m999989899999999
8 580573 6 5319697
$595205m9m4528044

0.120.1120.1 21.20.1121
222222222 22222222

910 542521219947
“707%570723355639

mlnnnluunmnnnununn

742960217 18607 02
1245834311.. A3732
0......
686456555655536555
3333333333333333 33

BBB-3B

6 3540 753400
134544241442323
999999999999999

93

22
...-...........

00
422250263482617
777777777777677
O I O O O I O O O O O O O O 0
000000000000000
7 274 154382 38
8M914m298344%82
O I O O O 0 I O O O O O O O 0
343444433444434
7078 6819 211
O O O O O O O O O O O O I O 0
888889888989888
631 2 61552

5 3 3
.0.%. .nwm.0.. 0%.M0
O O I. I.
O 0 000 00 00
066n03983139078
924 87774845224

unnumumuumuumnm
”mammmmmmmwfinwn

B6 ”Du/.66664nl.

6
111.11.117.17.qu

111

swme mammflnmwnuw
muLmnnfimnnM Dun
566773505912270
AJAAJfiAJomJJfiJfiJ
657766675555566
333333333333333

BBB-1

56274968702597
33672909405553
0 I O O I I O O O O O O O 0
64246564574656
99999999999999

6 9

1 O
.._.-......_..

o 0
9559003M802228
5556276 876665
00001000000000
84805624777194
12703467445643
0 I O O O O O O O O O O O 0
44344444444444
09125637350600
91588190927001
0 O O O O O O O O O O O O 0
88888989898999
2218332w65663
4554555 55545
O O O I O O O O O O O O O 0
00000000000000

646 4849

”.1 211u.1nwnu.1n.u.1

0.0.0.nw0.0.0.0.0.nw0.0.0.0.

92 9830 756511
29n63—J85

82834..4..

n9nnmmmmmnnnmn
mzfimmmmmnnmmmn

lmununmunuuun
.emmmmmu 4s

66
33

666
333

96.46
92.15
95.16
97.03
94.82
96.36
97.63
93.23

....flflflfl
00000000
99.8.

0 0
44444444

00......
97999998
3 7 2 75
5M4a5w44
00......
00000000
5 5 3 65
omomomoo
00......
01000000
13886195
70.71~I.79m7

nmmum

Table 4 (cart’d.) .

aam.um
“%MMflflmm
nunnnuuu

36.00

Field No. sic:§ A1203 Feo Mgo cao Nazo x20 T102 Mno Ba0 Total

Bm4(mmm
LMfi

18429031653758476498u11371
27367066304394322997 79324
00...... ......OOOOOOOOOOO
15666565776438656565766655
99999999999999999999999999
00 18 5000 2 780772 06
«m2 22 1121—2u_231772 12...
0000000000 00 010030000
916 9282305328938309800646
343 3434443333743443344343
0............COOIOOOOOOOOO
00000000000000000000000000
$50m25839 9195975294 42806
.78w 97978 5069829858 72977
......OOOOOOOOOOOOOOOOO
55555555555655565565556555

456110 6797 508121261762 7
20000859089W589508690009W9

......OOOOOOOOOOOOOO. OI...
89999898988888889878999898
2903271102239114“9502791“9
abo’nwalo7767alo77nlo85wlo77 677766.]. 6

O... O. O. 0...... O. O.
00000000000000000000000000

7 3 2 3 5533 6
.- ... .- .- ...0— ...... .— - .-
0 00 0 0 0000 0000 0
71793611692 2 390130 82 9

0...... I...‘OOOOZO£4O£30 0.2. .8“
uuumwuuumuuuuuuumunummumuu
.flwwmn unnmnmawmwuunmmmman

nuuuuumunuumuuuuuumuuuunun
nnmumsammumngmmnanummnfianm

nummmuuummmmummmumuuumunuu

322 9 00876 5624 28593 6
244a4m47789mw8383MW7HQmQUJ—JMJ
57777777777568757647877776
33333333333333333333333333

UWZfiA

.u
876
9999999999999
mmmmmunmnnnmm

00.0.0.0...
0000000010000

6.08
7 01
6 49

17
4.91
6.62
6.09
6.61
6 27

81
7 59
5.60

1358889629381...
4437333343634.

mmmmmmmmmmmmm
441867 605990
887877 500787
......CCOOOOC
5555556566555
14471 0796007
02212m8812780
......OCOCOCO
9999998889889
$99079679
66766666 776
......C......
0000000000000

146

533 3 5
.... ...... ..-
000 00 00

222 192244264
347 287097921

0 O O O O I O I O O O O O
uuummuuunuuwu
mammamgmmwmmn

0............
mummnuunnum1u
mwmxmmw%m mm%
0....... 0...

O
uunuuuunuuunu

99 2 952
nsfimmgsmfl.534
7777777766677
3333333333333

Table 4 (cart’dd .

FieldNo. 810::2031100 ago (20 Na:: x20 'I'io2 Mno BaO Total

IWZ-A (ccnt’d

36701826 634257
06293951E351962
......0...0....
765665768864666
999999999999999
822 53.222. 21
000000 004 0000
663123666176272
344446343434334
......0......0.
000001000000000
“.825 5MM1711 384
”97.7. 9.89.8 988
6555556556.55555

man7 MMM mMMMMMl

8880a889QuaunhQu8Qn99.
032933

n:nanm 777677

0......00... .0
0.00000000000000

OMMM1M. MM.

. ...
0.nm0.nw0.nw nmo. 0.

fiM72M12MMMflQMMM
151.51M51muuuuuu

magmas. 32m814m

44unlnnmuu1uuuu

1562441 718
527.8170" 338

nulnnn44uuu

7 99521462
.me9 M3 Ema 4956392

0....
6.6.6.87.7.87.84..76767
3333 3:33333

LW2-5

97.92

53 0.10 97.14
7
5
97
9.
5.
8
8
8.
6
7
7
6.
4
6
6
6
5
5.
6.
6
5

999999999999999999

2116 194403 49189293354274
.5263.104482nw21210932212202
.10.nU.0010 0000000010000230000010

4335433 61928964065492778578
7364444“5M64443354434215553343
0

.1536 .306709667608405468540584 86
82029120907749977677660 .19

5.79 0.45
4 0.
0.
0.
0
0
0
O
0
0
0
0.
0.
0.
0.
0.
0.
0.
1.
0.
0.
1.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.

9 6. 88 0.28 3.13 98.51
5.
6.2
6.
46
6.
5.
6.
6.
5.
4.
5.
6.
6.
5.
6.
5.
5.
6.
5.
5.
5.
5.
6.
6.
4.
4.
L
6.
6.
6.
5.

1
1
96

165735 7825552579767 5392 8
won/938050856590499705$9088MW

799789888899988888988889778988988

.7
.0
.0

7552 “:195169wn639161702 35376126
7778 767776 777877677 75556766

m00000000000000000000000000000000

0 3 7 0
........... ....................

000 0 00 0 0
“:9 5&951334 2129613000443201175
763364 2J84..0.7.7.nv.87.0~6638628
4.4. 444444 44 44 9.994444
M55191111115555115511m1nn 1111

751288355528 121 38073 :2726

nmwl92837946682fi354 53157. $80.9353

4uuunn111nuuu uuuuuuluuuunnnnnnnn

873946 4 61042256 57005267
280323mm4u86826882n“ 2m.nw0.3564..80~$mm

mnuuunnnl unnnuuunl llnuuummnunnn1n

55380615 073
2A3

55
7.787..I.768867.—I.-I.7556657767
33333333333333333333333

35.8
38.3
37.7
34.8
36. 55
35. 9*
217. 2
363.53

.6
3

37.

97.12
96.95

0.44 96.42
0.34 95.61

5 0.36 96.67

47 0.11 95.74
93.88

93.51

0.54 0.10 94.25

95.38

0.09 95.35

52
55
45
59
53
5
49
0.51

mmmmmmmmmmmmm
mwmuuflmmmum..
6555554555555
mmMMMMMMMMMMMMM.
8899989999888889

0

84063
11111

42943
77777

ooooooooooooo
0000000000000

no...
00000

89

15

46

Twh4(mmfi4.
14.82 0.07

14.97

14

15
15

14.95
14.93

..00.
muumm
098052043
462900713“.

. 0 . 0 . 0 . . . . 0 . . .
ununuuuuuuuuuuuu
mnwmmm

muunuunuuuumuunu
numnu

776776
333333

37 04

37
36
38
37
36
37
37
36

FieldNo. 810?sz Fee 1490 (no Nazo K20 1102 11m 330 Total

1142-5 (corrt’d
1142-10

93.00
97.30
99.41
97.69
99.02
99.19

99.18

96.80

98.87
98.78

99.12
98.53
98.23
98.94
98.56

93.84
97.41

97.23
98.18

2346595958732901782
2222722222233232223
. 0. 0

00...... 0 .0....
0000000000000000000

“75 033023361561“5&
.56 766666767667 6

mmmmmmmmmmmmmmmmmmm

9557n1m856606 1613
4042 5 455664 6666

000.000.0000.
44444444444444.4444

4841 02190 277849
. 0

.. ....0........
8888899998999989999

Mumawsmaam QM 9...»an

coo-000.000.0000...
0000000000000000000

mmmmmmmmumummmmmmmm
0000000000000000000

73 13142689492 50
£53m53890174384wflog
0 ......0......
99099 9900 90 00 0
1 9 119 1911919
900 4811927884847 5
801 AJ22853711474M3
.0.. ............0
1021 22222212322223
2222 22222222222222
38991 8 5556 6
aavaozmmlmsvsaamsmm
.0. 000...... .

uuuuuunmuunnnununmu

3757210 9 6 797279
...oooooooooooo

457666766766
333333333333

36.9
36 8
35.6

36
37
37
36.3

95.91
97.43
96.05
96.65

8 4.37 0.67 0.10 95.28
95.66

4.39 0.60 0.10 94.55

.91 4.89 0.76 0.93 94.39

.08 4.56 0.73 0.09 93.83
94.17

96.13

4.33 0.67

0

9
3
.93 4.25 0.77

.28 4.51 0.66

57 9.15 4.26 0.72
8
9
9
8
9
8
9

0.53 9.37 4.31 0.71

15 0.50 9.32 4.26 1.80
0 59 9.12 4.72 0.65

mmmmmmmm
75 6
07M0m
0000000

flnmafl

09

0.03 0.51 9.17 4.48 0.62 0.21 94.52

27 6530
.. J3.33£J
MDMDDMBBMM
365970735
038250654

mm.mwmummumn
mum ngawmnmm
nuumunnumuuu
mmmmxflfifl

677686764567
333333333333

LNfi-lB

114

Table 4 (cont’d.) .

Field.Nb.

A5% mo mp an mwagfi Tmzum aw mml

%

Si

1W4-1B (cart’

95.62
94.05

8.64 4.70 0.76 0.80 94.35

9.07 4.44 0.62 0.09 94.74
94.94

94.32
8 9.37 4.41 0.61 0.16 96.47
93.81
95.30
95.62

3 94.61

68 3
10

0.nm0.0.0.0.000000

417uun

1
1

7.0H550.6““2531367
656666 6.667.66Aw

10000000000000000

72
26
.64

35D6 uwnuamwnwuu

Audududutdududududutdududududu

4.49 0.67 0.24 96.90
4.57 0.62 0.31 95.18

.08 4.43 0.67 0.20 94.21
.23 4.94 0.69

8.96 4.49 0.68

.25
.19

3263 %611an693—J—I.
4222892002

.On889.80”O”O”On880uOn90n

9.22 4.36 0.70
9.28 4.62 0.66

9
9
9
9
.57 8.83 4.41 0.68 0.89 95.80

.43 9.10 4.52 0.59 0.23 95.24
0. 54 9.20 4.34 0. 70 0.22 96.79

8 9.31 4.31 0.63

53319609
.4..4..A5AJ54“

.5
.4
.4
.3
.4
.57
.50
.5
.5
.3
.4

0.44 9.07 4. 33 0. 62

0.0.nU.0.0.0.nmnwnU.0.0.0.0.

mmummum..mmmm
0000000

32 0 46 8 69 4. 64 0.

.40

9

6
0

8

3
0

9

16 0.48 9.

14
.11

5 0 45
51mfinwm.0.mm1m10.%

351
4.4.4.

4.4..4u4..4..
11111u11111

6743525
1818427“

44444.

4
0
0
0
3
4.

576522 89 44310
3 2nw0.8 3:133nw8

2
uuuuunumuuunn1u
6%5

4..

1
12 647 036335
“u.4“unamwnmnwnu.a“wmw.lnw.9_a .1mw.amwnw.3uwnu,o.8.onw

E15156 mwumu6wummummlm6um6mmumwmmm
“mun“ 6M1%:63 mnwaunmmmumwwun

nunnnlnnnnnluunlnnnlnnln1unnnnnun

7 14.33 0

69
2.
0.
17
.7.2
.dudu
11
10
83

)1 02 935312 96917998 43137 926760
65.2 JJ8585m36.7.4”5853 7.4..’6.-I.4.. A3253?”
766665666766777567797677776668667
333333333333333333333333333333333

DW4-5A

38639199695433
51465940623278
86541254717455
99999999999999
398 0 7 697612
100.7”0 107122
000 2000000000
1185911874 265
5555255454 253
0.000.000.0000
00000000000100
14203116936 26
92353453597 67
34446443434445
19417509 719
00000000000000
88987887988888
10827 8n034 98
454 47
0

6
5
.4
4
6

nmnmnunmnunmnm11nununwnvnvnv

«u

oo-
00

mmwmmmmmnmm

mmmmmmmmmmm

01 5u.4 290 445
38 2 37.1 44.9
OnOn99D.90u7.0nO”OnOnO“M.“
238 8&55190 510
4.7.6.59. 4.7.8

1111 11 al.2 20.2.

mmwam .mmmm. mam
nunn1nu :66 661
2935 567542

0.~I.5524..5265565
333334 3333

37.

Table 4 (cont'd.) .

fi%A%% mo up an 3mg>gp mmzum Bw'mml

Field.Nb.
INfi-SB

5166845JJ4734391131061muoOo331486219200214611
318998012272224247318 033740207891969364
0.000. 0.0000.000.00.000...000.000.0000.
7652457.66.562557787785657777767677737577575
999999999999999999999999999999999999999999
2334423473 9 481756 87 062693816 48 64
24JJ7.5JJ38 .5DB112J93. .44%273313718.12§®22.
0... 0.0000000... 0000.0
0.1nw0.nw10.0.0.nm0.000200121 001010100101 000000

520634316546839401939622394919520792142004
434333433242342433233343333233334234444443

0.0.0.0.0.0.0.0. 0 0 .0... . . 0 .0. .0 .0 0 0 .0 0 . 0 0
000000000000000000000000.000000000000000000
1553 50 993 52534243 4933379085 782
Baa—[.8 828 J330~2583$fim8 ”%m4892745090m679
565566565656556566665536656665565656565555
594 8 804125 7055 9 4 802563867

238 w:86. 68m422109m0184m m8 m8 21.0.Aw93312

988888988898898998889998898989889899899999
”5312232569851fin615670353329807280 4403230

.JJJJJJJJJ$JJJ..J£77££JJ£JJ£JJ£JJ£.JJJJJJJ
000000000000000000000000000000000000000000

o.oo. om .mmmmmm... mx.nnmmmomom1mmmmmmm .mm5
o 000.0.0. 000000 0.00 ooooooooommmmmmmm 0.0.nw
maammn .wux auman. u:m um omnmamw .mmmamn

4.

4..4..4..4n4.. 44.4..4..4..4.4..4.. 4...4.4..4.4..44..4..4.. 4.4...
3nu.o.3“19983175155096604105321 0429551.
7138 43712385738328243918740 $388323

lulnnnuuunlnluuuuu4nuun13111n1nn ununnnn4n

numan .mmmu Lama unmagmumunmmmau .nmnnnmmfimfi.
LLLL11LLLLLLLLL1LLLLLL11LLLLLLLun1uu11uuuu
nma7 Lug mgawmwmmmnmum1awnxmmm1 .nm11 .unmmfi
7.56.556.7.66.56.4..6 557.7.6.46.6 7.56.6.7.67.57.Am676575.78676
3333333333 ::33333 3333333333 3 333333

LWA-IOB

94.59

&:M7

muuuuu

087509
52.1538

116

Table 4 (cart/d.) .

)

Ah% mo mp an mwaxp Tmzum Bw'mml

1

'93.

1144-108 (cart

S

Field No.

9239m74
3734 02

o o o o o o o 0
10000400
6 024840
mlmnlzlllsfi
o o o o o o o o o o 0
00000000000

8837 52 121
4981M88M554

&&&&&&&iiL&
mmfimmwummxm
88898798898

3&4... 324978
8 77 887657

coo-coco...
00000000000

N£flm...m..M
0000 0 0
1570910525a
JAAJ£A£J££.
uuumuuu usn

mmmmwmmx.m&
uuuunnnuunn
mama nnmumm
O 0 O O O O O O 0 O 0

44444 44 44
11111511.”qu

35.06
36.46

CP3-2A

97.01
98.46

8.49 6.40 0.35 1.45 98.01
3
3
2
3
3
3
3
3
2
2
3
2
2
3
3
3
4
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3

633483935182 89642057 740 969019
128375588744n22027521 444mm32545

1
1
0
3
1
1
3
3
0
0
1
1
0
1
1
2
3
1
1
1
1
0
2
1
1
2
1
1
1
1
1
3
0

10728 5728006558029950

00
4339549 22 54454 3331173242335353

...-......O. ...... O. ......C.’
66666676666666666666666.666666666
51606M2203 318037

6
“gum““mmmwnfifina 52268 4704 574768

.0. I.60..........OOOOOOOOOOO. ...
888788778888888878888888888888878

8.43 6.40 0.29 1.42 97.94
8.06 7.00 0.32 3.33 99.20
8.59 6.61 0.35 1.80 98.59

$wfimwwmmwaawwwfiawaM$wmnnwmmfinmannmwnn

coco...oooooooooooooooooooooooooooooo
0000000000000000000000000000010000000

66
m «mm m mm 00
._.._..._._..-.-........-......_.._..
o 000 o 00 00
06$44048361313053695759704%726204203m
99 .87—[7944387.38797637m7odh64ham .Joonw32429m6.
O O O 0 O O O O O O O O O O O O O I O O O O
4 44444 44 44444 4 44444444444 4
lnllll1B1lnnuuulllllunlulllllllllllnl
46163065666 833753 0 912 11 914 553
n 4 film m 04
O O O

JdfiauxaAamnwAfi .aJfijaaa . .anfi .33 73?.” . . . .
uuunnnuuu umunuunuuuuumuu uununuuuuun
wuwmmmmamunnmwmmummmfiummwanmamaanummm

O O O O O O O O I O O O O O O O O O O O O O O O O O O O O O
Bwuwnmumummmuuuuuuuuuuwuuuuuumuuuuumu

99 28 0111 60 6 515 5796 91.21 023

86%92m1354mnv81fi3w706 9184ama6osfll43.
6566677555547676766645666656566566647
3333333333333333333333333333333333333

117

Table 4 (ccnt’d.) .

Field No. sic? 111203 F60 1190 <20 Nazo 1:20 T102 Mno BaO Total

CPS-2A (ccnt’d

871 60730321 6146 39175650204 37 1 03679 94251
Jalufiwuoflw8w747250 5192a96542040680w08mfl6 38563M94864mn
7566586%9089 5616546457657515744553 7666737776566
9999999 9m99 9999999999999999999999 9999999999999
860154071491 659475u75smo38w863 291 52 6620397 2
756434449927 343447 244 451 054.665 3.2122121. .2
111112131220 000000010000000000 000 00 0000000 0
199420201930 4107340562272998298410 3772564570....“4
322333345944 3333333323323222322333 44344344474 4
. 6 6 6 . 6 . . 6 . 6 6 6 6 6 . 6 6 6 6 . 6 . 6 . 6 6 6 6 6 . 6 6 6 6 6 6 6 6 6 6 O 6 6 6 6 6
000000000500 0000000000000000000000 0000000000000
8903 590 695 6111 7 9 862645 471687 1860026500956
4244fl320$162 129151m2m128198m397112 5888478887766
6 . 6 . . 6 6 . . . 6 6 6 6 . 6 6 . . . . . . . . 6 6 6 6 6 6 6 6 6 6 6 . . 6 6 6 6 6 6 6
666666676666 6656666666656556655666 5555555555555
668566911440 36890798 1129801034790 709925633m180
RN94..R~73537727 38288882 9584737729555 109837222 000
. 6 6 6 . . 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6
878888888788 8888888888888888888888 9988989999999
461594381884 9 6 1 O 9 9 163 322 26252365 66
6 . . . . . . 6 . . . 6 6 6 . 6 6 6 . 6 . 6 . . . 6 . 6 6 . 6 6 6 . 6 . 6 6 6 6 6 6 6 6 6 6 .
000000000000 0000000000000000000000 0000000000000
6 6 3 6 35 0 6
..w....nmwm1o.mwm_..mm..m.m.u.o.ow . oo.1....o.m
6 . 6 . . . . . 6 6 . . . 6 6 6 6 . 6 6 6 6 . .
0 00000 0 000 00 O 0 0 O 00 000 o 0 0
9625619911. 6 96961714 6008 1779 33462 51.9 01
. . . . . . 6 6 . 6 . . 6 6 . 6 . 6 6 6 . 6 6 . . 6 6 . 6 . 6 6 6 6 . . 6 . 6 6 6 6 6 6 . 6 .
444 444444 44444444

lllnuuuuuuum umnuuuuuuuuuumnullllll muufillllllll
8.13....818. mm......m.m.mx..m&.m.m ..mflnm&mm.Mflfl
unnunuuuuuun unnnnnnnnuuunnnnunuuun uuuuuuumumuuu
fi....flfi...%m amaummmxmnmmmfififlfiflmflmm .mmmmmm11.mmfl

6 6 6. 66.6... 6
mummmumunuu munuuumuuuuuunuuuuuuun unnuunuuuuuuu

1

50351. 03 1 3 0231.9 6 633095 2050 68 1 9720715
6.6.6.666... .6....6........6...666 666......6666
655556656458 7757667577667756767675 7677767877776
333333333333 3333333333333333333333 3333333333333

CP3-ZB
CP3-1D

97.55

0.33 0.23 97.96
0.42 0.25 96.38

8 0.43 0.56 95.24
0.39

4 0.46 2.29 96.85

118

Table 4 (cart’d.) .

Field No. 5131;1203 FeO 1490 (no Na20 1:20 T102 mm 8510 Total

CP3-1D (cont’
CPI-3A

0315752429808110120
4230223131933326322
6543616486656761167
9999999999999999999
040

Bulllfimm...........
. . . . . . . .
00000000

25958

695m’01167181
545 46544445 43344

00.nwnm0.0.0.0.nmnw0.nw0.nmnmmnm0.nw
90263n6299666339 43
34....”35 6334334330 25
O ......O.........
4444444444444444444
1512259 5358510885
8522567$0098004379
......C............
8888868899889986689
26 128176216089 596
5Afl553543444443 234
......I.......
OOOOOOOOOOOOOOOOOOO

3 33 05
no m.o m43m
...................

00 000 0000
596331324313 784 47
33 79

5.43£.243n3nm
99m999999999999

a.Mflflflmumm.mwamsfifim
2110203223211210022
2222222222222222222
wamm&mflmmfimmmflm&mmfi
uuunuuunnnuuuuuuuun
unmflMfiMMfiflnmfifi&flmam

C .
6&65664575766678766
333333333333333

GUB-ll

6B811m663190391703715207
4 408 34791495043844.3538
677556656797666575768685
999999999999999999999999
9 7 6
0 no 1
........................
0 00 0
601125333754663972072 8
M656785545777658566565$9
. . . . . . . . . . . . . . . . O . . . . . . .
000000000000000000000000
519927780205433007242195
355333440554454451536554
. . . . . . . . . . . . . . . . . O . . . . . .
444444445444444444444444
4 21.. 7 340418 3209508
. . . . . . . . . . . . . . . . . . . . . . . .
89999988m999988899999998
7221933296 611. 631. 3053
. . . .

576
......O....... ..

000000000000000000000000

3 37 3 3

m 0 00 0M0
........................

O 00 00 000

4816266033974799053748

2387048400884524905921un
oooooooooooooooooooooooo
O 9
9998u989m99898998u99919
136450n52906202m138 21.51.
287403 25217699 279 0484..
ooooooooooooooooooooooo
322302324433232236224032
222222221222222221222222

352044165 72698 6 043 49
357973545m95252“8&936m85

uuumunuummuuunumuuuuuuuu

8551.739 7089 098 45882

76
1443326 170247 859 43348
........................
666566551576656568666765
333333334333333333333333

100.45
99.98
98.93

101.17

100.11
98.49
98.49
98.01
97.79
99.29

100.76

100.72

100.72
99.32
99.82

101.72

101.84

100.35

100.96

100.58
99.41
96.76

100.19

100.67

IMHO BaO Total

0.82 1.08
0.55 0.93
0.82 1.10
0.61 0.96
0.44 0.94
0.48 0.90
0.65 0.94
0.62 0.80
0.65 1.00
0.55 1.10
0.80 0.90
0.48 0.96

0.59 1.02
0.52 1.22

0.59 1.04
0.46 0.86

0.44 1.26

0.55 0.96

19.61 1.03 0.41 0.56 0.97

20.48 0.66

0.14 1.03

T102

0.57 0.97
1.80 1.21
0.38 0.84
0.25 1.00

.07 0.59

.38 0.
56
.48
.54 0.64
1.55 0.62
21.38 0.67

21.06 0.64
20.95 0.64
21.59 0.66
21.57 0.74

1.31 0.61

1

1

1.

1

1.

1
21.52 0.73
21.33 0.65
21.24 0.64
21.06 0.64
21.20 0.66
21.07 0.71
21.39 0.62
21.20 0.63
20.96 0.61

2
2
2
2
2
2
2
2

13 438295097
22W143470142
0

......0...
444434 44.4
111111

885002206060881
936154051713938
.0.. 0 .0.

.0.... .
888988988898888

23662
0.000

Microprobe Analyses of Pyroocene.

0.00...
8988889

09513342353
66772328674

oooooooooooooooooooooooo
111111111111111111113111

9195467
4893346

Table 5.

22605 177045 02008753

8102 111203 Feo mo <20 Nazo K20
52.0
52.7
510
52 2
52 5
51
50.
50.4
50.9
52.2
52.6
52.2
51.6
51.9
53.6
52.4
52.3
52.9
52.9
51.9
50.2
52.7
52.5

550-10

Field.Nb.
BB9-1B

2919808381
0838062577
6888089998
9999N99999
...-......
54171624$0
69719342 1
0 0 0 0 0 0 0 0 0 0
0001011101
1229213173
5554433335
0 0 0 . 0 0 0 0 0 .
0000000000
...-......
636 737 7
575 565 .6
0 0 0 0 0 0 0 . 0
00000000 0

“9545w250
6892 263
000.......
000101110
2222222 2
16727730
“94834704
00.00....
434343 44
111111 12

6593479172
2646408549

00.00.0000
88888988N8

0 55466 7
1”06704”0M

on. 0.0.0..
2121111021

66 632209

64m440625”
00 . 0 0 0.0. 0
9101221231
4555555555

100.30
100.24

96.89
100.28
100.57

99.77
100.80
100.87

0.44 2.10
0.50 0.99
0.71 0.84
0.73 0.98
0.89 0.95
0.27 2.03
0.37 1.41
0.76 0.87

20.61 0.69

21.20 0.58
5 20.45 0.62
1 20.97 0.70
1 21.27 0.57
3 21.07 0.61
0 21.61 0.62
6 20.75 0.64

2
3
6
9
6
8
8
5

umuumnuu
gamma”

0......
8888m89

mmmamwum

.0 00..
11222012

52.2
53.1
50.2
52.1
51
52
52

BB9-5C

120

Table 5 (cont’d.) .

Field No. 8102 A120: F80 1430 060 N320 K20 T102 mm 830 Total
.)

BB9-5C (cont’

118984209372029069698W53765
331535078046863598219 98655
0.... 00.00.00.0000000000000
6809091001088110991080009m9
9909090000099000990090009 9

1 1 11111 111 11 111 1
........._........_......._
O4139780737579%98181321316%
99997898386212 88875788999
00.0.0.0...000000000.00.00.
000000001002221001110000000
648369676397032fl29949498$fl6
434644464452334 62435454 4
0.0.0...000......0...00.0..
000000000OOOOOOOOOOOOOOOOOO
....._.._........._........
5 6 96 512 5
95.96 9.9.9 96995 5..” 67.6 .199 9.96

000000000000000000000000000
9799 695 98313 9023917285
4132M857n67928as448244245m%

0.1111111110. 0.nm1111011111100.
2222222 2 222222222222222

222
62818305630076 166229
9 ”16923460430312 94..86.7.5m.1

nluuuul unuumunuunuuuuuu
9m99999999999949991995.90199909

7 5 063 156 8193335
3.598%955552 786 530%8755495
0.0.00.0000000000 0.. .0. 0.
111111111110001111111111111
4 328 32868 4294 163137
1””80.3 .894..4..1~fi20.53. 8—I.~I.nw0~8%6 “
0.. 0.
11213232233113322LLL1L29M222
555555555555555555555555555

BB9-10C

810220414833439713974
754097963150557376558
898989798998879892799
99999999999999999m999
.............__._..._
029357315D44274321n80
90809992 99989099 18
. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
010100011100000110110
769967061614513690809
532424123123528234164
0 0 . . 0 0 0 0 . 0 0 0 0 0 . 0 0 0 0 . 0
000000000000000003000
3

3
...-....._.-......_..
0

4267 551 908 916
7655““5 $6 666 565 67.5
0
000000000000000000000
52 253 24 6432
00000100000000000001
22222222222222222222

.JnMM9999999999mm n

mmuuLuunn1LuuuML1n4
m:nwmm«nn zmsnzmng

788888888888888808998

1739 23976 32 937

7466$54431fl84®539 35m
00...... 0.0.0.0... 000
211111111111111101111

1 O 1285 2 17705404
ZMSWAGAOMA86D780839£A
0 . . 0 0 0

331222132221212222122
555555555555555555555

121
Table 5 (cart'd.).
Field No. 8105. 341203 Feo Mgo Cao Nazo K20 T102 Mno Bao Total

BB9-10C (cart’

9 631.54 406617 74345
9%80124M193101WM85555
7888M~8908991180689878
9999 9909990090999999
1 1.1.. 1.

O

o
....._.._.__..._.._..

0
698392173919764604408
824278947727789088701
011100011110000100021
9730n41 3 40659186619
2421 44 2.48374213423
O O O O 0 O O O O O O O O O O O O O 0 0
000010000 00000000000
__...__......_.._-_..
32360 1.329 99322 9
’D.6.ab..&4..“w“M56.—55. Ans—56.6 .5
ooooooooooooommmnwnmnmnwnm
7333751010319342832
376—JJ3532 0%1J0w332
OOOOOOOIILIIIAWIO

O

1
22222222222222222
4

4..

197 9999999 99
unnnuuununnuuunn
9999n9999999umn999

78888888998888m87881

530521 38624 575302.56
539808 37727 59335892

ooooooooooooooooooooo
110031110011110111101

7970
1.001
2222
7943
3225
4

11mm
929
44....5
08

.11 73 2 2513081987 29
I4..—I.. 88 .6 3837.632336 48
211Lm1221222213121101
5555555555555—55555555

UWlfiA

100.75
99.80
98.77
97.20
99.37
98.29
99.60

100.18
99.26
98.77
99.57
99.18
98.87
98.96
98.99
99.87
99.81
99.44

100.14
98.66
98.91
98.17
98.34
98.66
97.75
99.60
99.22

0.33 1.75
0.24 1.72
0.45 1.13
0.44 1.81
0.33 1.14
0.33 1.26
0.29 1.23
0.44 1.13
0.36 1.27

0.33 1.32
0.32 1.35

0.36 1.28
0.28 1.46
0.25 1.56
0.25 1.48
0.36 1.22
0.35 1.56
0.33 1.38

0.39 1.37
0.26 1.45

0.40 1.32
0.27 1.07

0.26 2.26
0.45 1.03
0.21 1.10
0.33 0.92
0.26 1.05

1.29 0.75
0.89 0.59
0.84 0.72
.51 0.74
.77 0.88
.00 0.60
.31 0.74
.28 0.70

1.19 0.70
21.46 0.69
.7 21.29 0.66
6 21.45 0.66
7 21.25 0.66
7 21.03 0.69
7 21.20 0.66
21.43 0.64
20.98 0.70
20.71 0.64
21.21 0.79
20.76 0.70
20.75 0.64
20.82 0.62
21.09 0.72
21.31 0.61
20.93 0.64
20.86 0.62
21.56 0.59

57471 79 43863028

nunnnnn1nu1n1n1nnnnu1nnnnln

1&5460292742273351500 3603
22 7106273230748608448 39.4..2

...
998N98888888888889888888788

402 2182 0708 0006 1..
21.5 2310m3123m1432 2

11111111111111111111LLLLLLL

999994

39368456921m236332 86 0731.5
6788w—Jnd324hdhz Q~4...5385 52863
221.011.231129m1211229m11112122
555555555555555555555555555

122

Table 5 (cart’d.) .

fi%A%% no mo m:91mp 90 fi% mo Em hmu

Field.Nb.
1W22A

98.79
98.14
99.06
99.86
99.38

100.59
99.84

98.01
99.40
100.63
100.60
100.65
100.97
99.88

- 100.81

0.24 1.24
0.31 1.25
0.32 1.18
0.37 1.36
0.32 1.21
0.23 1.85

0.26 1.28
0.30 1.35

0.37 1.33
0.32 1.17
0.35 1.09

0.25 1.24
0.25 1.60
0.35 1.16
0.10 2.70

915

flaw? ama$676m6a6

m0.0.0.nu.0.0.0.0.0.0.0.0.0.0.
0523

2$u1039um2 55m

nU.110.11110.111110.
222222222222222

9132054711 892
6365992997 924
O

......OOOOOOO
unnnuuununnnuu
”mummmxuunmanmm
88898988QH900888HH.

..mnufimmm5mwmmfl
111111111111110

5&9 .mxa m:.

9535
5965

LW2-5

37967160855556
82170024375255
99099990899978
99099990999999
1 1
..............
9926270701M673
6782733293 321
O 0 O O o O O O O 0 O O O 0
00011111011112
25579369235607
43421343444431
0 O O O 0 0 O 0 O O 0 O o 0
00000000000000
..............
97 810
55 $;7.$“&7.Aw£w

0.0.nmnwnm0.nw0.0.0.0.

ommm .muum..
11nU.11111011
22222222222

6885510
B.‘wd..4..80.7.°~

321
655
000.
84

73u1
011
222

gas

55m

uuuuunnnlnnnuu
gunnmunnnnmnmm

7..I.-I.7.88887.8—I.87.nm

1

2 4 5 38185 4
6fl8a2 4444637
0.. O... .0....
11100111111110
667818 46 9156
18nw7.27 24nd..3
32333223223211
55555555555555

1W4-18

572983276703205845
049505660539080932
589908908987886780
999909909999999990
1 1 1
......._....._....
2m2972395140a13235
0 8999590010 91213
O O O O O O O I O O O O O O O O O O
121111112312112222
456693307436061458
222522222252322221
O O O O O O O O O O O O O 0 O O O O
000000000000000000

l

1
..................

0
935M629226257763fi2
566 675676665656 6
O C O O O O O O O O O O O O O O O I
000000000000000000
5W0404920373u606w5
7 4187749822 437 8
O O O O O O O O O O O O O O O O O O
001100110011110000
222222222222222222
429$2509 03290 787
337 7.4..32 38370 483
O O O O I O O O O O O O
wuuuuunnuunuuu111
111
5007278934 479
93261613899MB418

O

0000 00 110
91111999118999n111
941722 878 9589
WWBfiflfififlmm292 7.986.

000011001110100000

mwnwmmnmummmnmnm
mmammams wwwowwma

am

Field.Nb.

1W4-1B (cont’d.)

1W4-5A

DW4-SB

1W4-10B

CPS-2A

123

fi%A%% no an on

52.16
51.78
50.69
51.75
50.36
51.77
51.68

52.80

52.32
52.17
48.98
51.71
51.49
51.86

51.96
51.79
51.52
52.17
51.87
51.49

52.08
53.39
53.60
51.82
52.84
52.75
52.91
52.80
53.25
53.24
53.59
53.07
52.47
52.67
53.15
52.87
51.49
51.56
51.84
50.28
51.11
50.79
52.30
52.70
52.13

0.95
1.02
0.93
0.79
0.87
0.83
0.85

1.28

1.50
1.32
1.26
1.05
0.93
1.18

00000000 000
N Hmmm
QEQOQH

%8883883388358fi328833833$

HHHHHHHHPHHHNHHr-‘HPHHHHHHO HHHOOH

9.65
10.07
9.73
9.43
10.26
9.90
10.02

9.01

9.20
8.43
9.75
9.21
8.26
9.06

a
UN
”0'

kiss

000000me

.0 O 0... O
‘0
NHOO‘HO‘DOQU‘Q H

0
bUUUIgNU‘OQUUUDO‘UU

:OUWUUQOEUQQU

H
onqmqomqmwmmmmommmmommmmmm
00.. 0
009(3th

13.59
12.76
12.76
12.83
12.23
13.05
12.46

14.74

13.66
14.62
13.64
13.02
13.97
13.27

14.39
13.42
12.40
14.32
13.80
13.43

11.96
15.32
14.37
14.25
14.27
14.13
13.40
14.45
13.30
14.64
14.47
13.61
14.36
14.70
14.75
14.93
14.19
14.38
14.40
14.02
13.22
14.75
14.67
14.96
14.35

21.63
21.05
21.28
21.26
21.28
21.54
21.04

21.44

21.13
20.65
21.11
21.11
21.55
21.27

21.46
20.98
20.78
21.27
21.72
21.59

14.63
21.51
21.72
21.29
21.60
21.55
21.34
21.50
21.52
21.73
21.53
20.79
22.01
21.50
21.35
21.35
20.98
20.72
20.95
21.38
20.52
21.71
21.54
21.05
21.00

Table 5 (cont'd.) .

oogooo
$32888

oooooooooooopoppppgppppgr
888328828388§$883§3$$§$32

999999
UUNGNU
mom 0‘)

c:c>c>c>c>c>c>c>c>c>c>c>g>c>c>c>c>c>c>c>c>c>c>c>c>
a.u»uau»n>p-u:uua»9.9.9.01uia-unn-o»u»unn»ununh.o.
C)b-h-GI~JC>O\C>¢-h)0\0\b-b-U|U)Uih)\lh‘0\h*hlhlh)

i

Q-bUID-‘U'IDU

h'h'h’r'h'h‘h‘
\0\0¢3<ncn\o<n

an
ax

333862 588583

karat-rac>ha c:

{HOPE-“HO

\looqquuoxoooxoor-uo

OOOOHOOOOHHOHHHr‘HHl-‘HHHHHO
\lOOChNJ-‘b COO
UIH\lObOOHHNOngUHHOGSGUQgg

g

OOOOOOOOPOOOOOOO
HNNNNNNHNNNNHHNH

mwuwommmpqmmmmmm

Irmzu.

100.78
99.64
98.15
98.76
97.92
99.95
98.93

100.16

100.29
99.13
96.93
98.60
98.36
98.73

99.46
98.53
98.91
99.18
99.27
98.77

98.17
102.68
102.73
100.07
101.35
101.28
101.35
101.73
102.75
102.29
102.08
101.39
102.19
101.56
101.83
101.70

98.86

98.85

98.62

97.40

98.58

98.50

99.73

99.84

98.94

124

Table 5 (cart’d.) .

Field No. 3102 141203 Feo Mgo Cao 19:0 K20 1102 um BaO Total
.)

CP3-2A (cart’

,0 nu5115=31.1.nv1.2. a.4.n.n.n.7.4.1.1.o. 1.
.bnm.u.4,o.9.4.9.o.3.8Mm.a,oqlnu150503nvnu05mu1.
nvoanvcanVQJOJQVQJnVQJQJcanvnvnVQJQJQUQJOJOJQJQV
nuolnvo.nVQJOJQJQJnVQJQJQJQJQJnVQJQJQJQJQJQJQJQJ
1. 1. 1. 1. .1
................_.._-...
,0.3.9,b.1.4.l.1.J.4munu.4./.I.b.3.4.3.2_5mm.3.2
7U7H7u7.nvnuv.n.n~7u .nwv.nmnananqq,157.=3 can.
nunununununununvnvnvnvnunv1.1.1.1.nv1.nvnvnvnunu
7.:37.:3Avnvnvn.057.:.1.=31.nvnv7.9.1.5.7.o,7.:3
1.1.1.151.4.1.4.1.1515.4.5,o.5.8,o,o.4.4.4.J.4.4
......OOOOOOOOOOOOOOOOOO
nununununununununununununvn.nunvnunununununununu
.............._........_
.5 9o. 530.1. nuwlq:
9.59999 5999599 555 5339.9

000000000000000000000000

805905 1229 932 0269280
30.4..839m 7745”953m2649643

1110111001100B00000EEB
2222222222222 22222
199.99

9995599999999999 91
muuuuuuuuuuuuuuununlnuln

8W2 HMZO m:84..16.8 988304

92837 .814..~I.82
0 .nm 0
8887887788778mm1 1M1 n.88

9999999

903 63791929594
65$“5fi43273403334

111111111111111111111111
616318 2534674
54svoa5ammmn use. .7571455
.0 O .0.
32223 2232222 110.111111
55555a5555555m555555555

CPS-23

378555323u564m12527315
995687965 694 35831213
8788888887899878888899
9999999999999999999999
........._._.._....._.
73682790 5364925889
6W0 9199141w9898940106
I C O O O O O O O O O O O I O O O
nm111nm10110110001011110
4140610405594096183593
4344344243434532423343
O O O O O O O O O O O O O O O O O O O O O O
0000000000000000000000

5

6
........-..._.__._.._-

0
90517 5099719 3 00 6
O O O O O O O O O O O O O O O O O O O I O O
0000000000000000000000
4837 20900233 58765461
0 O O O O O O O O O O O O O O O O O O O 6 O
0000811010000000000001
2222122222222222222222
8 563 41 515261 5449
O O O 6 O

433 4 4

n111mnuuunl .1nlnnu
7373061M57976161 583
A0.16—I.3 5 54..93nw 4nw 229
8888788088878889887888

1
5995.5554255..U9555955
1111311111111110111111

5:1m9

974

1

8:23371402 85.4.
.1
5

52.5
52.

51. 84
51.78
53.5
51.5
52.0
51.8
52.0
52.0
52.1
53.2
52. 58

125

Table 5 (cart’d.) .

Total

BaO

9%Ah%,mo mp an mgagp tmzmn

Field No .

CP3-1D

116814fl4775176.5“29694665710083”
717258 30125351 55974114355599
9709889099”87898777887878797879
99m9999m99 99999999999999999999

0

0
....—...-....-............_._..

0
689665-]“6854028968273007mn66703
1031382 9253262233412370 12222
1111111111111011111111122111111
47.509 2%68804296318114646313197
32421.2 31333232444443325353534
I O O O O O O O C
00100 0000000000000000000000000
6
.5
....—..—-_.__....._...-.._._..
0
19 131 133109935 26697
7.5 al.-50" 66666677flama—5 6.56nw5
O O I O O
0000000000000000000000000000000
98 1153 5 648233 810165
4..?— M: .8—I.QH_5 $M5fl423224 mm36.3555

1111111L0.111111

222222 22222222222222222222

6407725507617377 6952 627063
“9749954287454212 3635“17.16.8Q~

nunnunnnunnnnnunnulnnnlnnn unul

99999599999999999199n999999 9mm

8888888998867777787777788777777
983318 794854 84192 48 8203337
”482673%0.4“130.9 94.53.5m3 3330.4..4..Q~
0...... O...
1201101111111010111111010111110

5128619223008 350942972 071 9
0&79728646981Awfi0w7 853345007.3
000...... .0...

2 21122222321231111222222239Ma/m23
59.355555555555555555555555555555

Field,NO.
BBB-15B

DW4-5A

CPS-2A

CP1-3A

Table 6.

126

fi%Ah% mo mp an

46.5
46.87
48.14

46.85
47.15
46.24
46.69
46.84

39.51
39.72
40.98
39.84
39.38

45.03
45.79
46.31
47.13
46.65
47.31
45.12
45.56

7.09
6.27
6.19

6.74
6.96
6.56
6.78
6.80

?????
83288

0\0\~I?\a\a\a\0\
aaagaaa:

18.61
17.24
14.33

18.64
19.38
18.32
17.75
18.00

15.07
14.94
14.07
15.35
15.53

18.28
19.36
19.51
19.30
19.24
19.40
19.51
19.38

11.21
11.99
14.21

11.26
10.99
11.11
11.31
11.57

11.65
11.37
12.29
11.27
11.10

10.93
10.59
10.85
11.00
10.51
11.71
10.44
10.60

10.20
10.51
10.46

10.40
10.28
10.40
10.25
10.49

11.45
11.41
11.54
11.58
11.23

10.11
10.04

9.99

9.97
10.17
10.23
10.00
10.00

my

1.87
1.87
1.91

1.98
1.83
1.72
1.82

...
0
p

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O.

NN-bl-‘U

HO‘NGO

P’P‘hlf‘r‘h‘k‘h‘
\J\Jh‘GDGDGJ~J
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00
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c>c>c>5>c>c>c>c>
$333$$$é

Rfischmo e Analyses of Hbrnblende.

T102

1.52
1.46
1.22

up
UIU

9:hafoh*ha
hau>g;

#:5th
O‘NOUQ

OHO‘NO ON

F‘F’h‘f‘h‘h‘h‘h‘
u:u:u:n»u»n.n.u>
nih‘03hihDh-F'F'

hié-F'F‘

c>c><>c>c> f‘hlh'h‘h*
P’h)p'UIF' gru:¢.n.o.

Dmehd

NU
UIU'I

r'h‘hi
a:
.h

1.32
1.37
1.34
1.42
1.53

0.27
0.30
0.26
0.23
0.33

Tbtal
99.14
98.26
98.57

99.44

100.08

98.15
98.80

100.96

98.47
99.20
99.78
99.40
98.62

96.42
97.49
98.80
99.48
98.90

101.99

96.78
97.49

127

MummwQdeaofmmmdwa

muem

fiQAh: mo mo mo m§»go fi% mo $0 mml

FRMNQ
BBB-10C

8683m108160m03370294609
4235 072631 03470184667
58676767898999099989w87
99999999999999m99999 99
013 3054257240097676011
174 - 3323546534884453443
000 0000000000000000000
97
33
.1....................
01

55 8866

00 0000
..................._...

00 0000
22580101797937881790336
0 873224442865014454669
.......................
11101111111011111101100
332 22 6 07988560860038
....... .. ...........
33434777776677667767787
1377462 8080 716766
3730953 .4237 .659513“

03361106
1333334..3
nU.

0.0.nm0.nm0.0.0.0.0.

3&2 smumfiz

25 0
4

0

56

38

4..4..4..334..5

2 22

5

3

55374
22222 2222
mannumnmfimw
sawmw

:2... ..

60 052 23 50 0 43
60. 66 23.69 0.35
59.34 25.13 0.45
58.83 25.16 0.43
60.16 23.64 0.39
60.35 23.58 0.41
57.32 25.69 0.40
60.99 23.46 0.36
61.32 23.31 0.44

.51 23.26 0.40

.04 22.95 0.41

60
60

EBB-153

58821876357820682w11
95.158596504303407 68
779090990 099990999
999090990m099990999g
1 1 111 1
..................._
........-.__...._.._
.......-._._.......
9 47416449486 473 55
5 81222229113n23ln32
O O O I O O O O O O O O I O O O O O O O
01011111101111111111
753 798SW65089515137
378 889nU. 88888949800
0 O O O I O I O O O O O O O O O O O O
78888889888888898899

3 2 36731169 0770
.0 0.. 000......

O... O
63333333333333323333

uummmwfimaflfifimflufiflmmm
00000000000000000000
flmmfiflfimwmmmmmmmflmfiflm
52121211111111111212
22222222222222222222
muunwagmxmwa .nmwm.fifi
mamammam “a“. asaammm

99.20
98.35
96.37
98.98
98.68
99.70

99.60
97.76

99.29
100.05
99.88
97.14
99.78

100.08

86216
12731

0.0.00.0...
1110110001
622891
120.9wab.0n
88888QH87888888
11131
$3364..
33353357.533334..

128

T&h7(mmfid.

.89 0.21

1.72 0.23
.58 0.19

125.35 0.14
61.15 23.27 0.18

0

2

165 23.63 0.20
2
2
2

157 21.62 0.22

63.72 22.46 0.18
63.21 22.13 0.18
63. 97 22.05 0.24
61.08 23.80 0.14
64. 25 21.85 0.20
62. 82 21.83 0.24
61.21 21.29 0.22
63.

FEMNQ $.21 an up an c: 0 fl. mo an and
342% Na2 Q %

m&53(
mvm

3.4.nua37.11qz,o.8.8
9.0.9.11q2a2a1,6.8.9
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oanquQJQJQJnVQJQJQJ
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22.9,o.4,o,o./.1.3.5
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1.1.11nv11nv111.1.1.
n.7.n.q.4.=.1.o.o.
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550000 58
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000.00....
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221.].15121
222222222

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7151513306
7664919460
8758077600
9999099900
1 11

3 8 110
1. . . .0m8w111
0 00000
......_...
...-......
191056968”
323322442
. 0 . . . 0 0 . . .
1101111011
96 6837 76
. 0 0 0 0 . 0 . . .
8858888688
2233433523
446485 945
. . 0 0 0 0 0 0 . .
3393333733
......_...
7004
unmmnmllls

nwnmnmnwnwnvnvnvnunu

2.1.1.1...

99.10

- 4.10 7.40 2.07

61.91 23.50 0.12

LWlfiA
DW2-5

87610197
70433326
. 0 . . . . 0 0
77798667
99999999
...-....
........
...—....
7793

2226

LL0.0.L0.LL
mm c.1.q.1.4.9.

7.nwn~7.7.o~
.5.8,6.1.I.5.I./
.2.2./.5.3.8.1.5
.2,6,onununa.2.8
1.4.7.7.132w4.1.

m. .1mm2
AU. 0.0.0.nan.
3 sanwmn

340663.].22
22222222

oamwma o

1 391
6%55 556

129

Table 7 (ccnt’d.) .

Field No. 8102 111203 F60 1430 C20 N620 K20 T102 M10 830 Total
LN4-1B
64.22 21.61 0.23 2.81 8.39 2.02 - 99.28
63.07 22.84 0.27 3.73 8.42 1.41 — 99.74
61.77 24.18 0.20 4.64 8.17 1.03 0.11 100.10
63.55 21.84 0.32 2.70 8.75 1.96 - 99.12
62.87 22.37 0.24 3.61 8.64 1.48 - 99.21
64.25 21.23 0.19 2.94 9.00 1.58 - 99.19
63.40 21.53 0.24 3.08 8.47 1.71 - 98.43
61.49 23.35 1.02 3.90 7.68 2.05 0.18 99.67
60.35 23.28 0.88 3.94 7.16 2.01 - 97.62
61.22 22.88 0.82 3.88 7.30 2.39 - 98.49
62.65 23.87 0.79 3.71 8.07 2.27 - 101.36
59.38 22.59 0.75 4.17 7.02 1.91 - 95.82
61.34 23.76 0.82 4.34 7.49 1.91 - 99.66
58.82 22.59 0.79 4.01 6.80 1.96 — 94.97
59.57 22.65 0.72 3.94 7.20 2.08 0.18 96.34
60.53 23.07 0.81 3.85 7.29 2.20 - 97.75
59.44 22.95 0.83 4.23 7.16 1.81 - 96.42
60.98 23.24 0.80 4.06 7.21 2.05 0.15 98.49
59.31 24.48 0.90 5.41 6.88 1.34 0.30 98.62
58.43 22.53 1.01 4.04 7.42 2.28 0.14 95.85
61.37 21.70 0.51 2.36 6.63 4.82 0.43 97.82
60.83 23.13 0.63 4.13 7.70 2.14 0.15 98.71
58.73 22.72 0.65 4.17 7.33 2.10 - 95.70
61.47 23.43 0.60 4.21 7.62 2.15 0.08 99.56
58.80 24.06 0.39 5.53 7.10 1.55 0.34 97.77
60.05 24.91 0.35 5.29 7.27 1.60 0.56 100.03
59.25 23.39 0.39 5.09 7.29 1.76 0.36 97.53
61.37 23.75 0.28 4.75 7.42 2.14 0.31 100.02
58.81 24.58 0.40 5.83 7.07 1.42 0.36 98.47
60.86 24.40 0.35 5.09 7.27 1.79 0.41 100.17
60.58 25.02 0.44 5.15 7.24 1.67 0.24 100.34
58.51 24.11 0.38 5.32 6.73 1.62 0.21 96.88
61.71 24.97 0.36 5.26 7.58 1.73 0.35 101.96
58.61 23.08 0.34 5.23 6.87 1.69 0.36 96.18
59.62 22.38 0.36 5.17 6.48 1.94 0.30 96.25
59.43 25.50 0.41 6.26 7.18 1.21 0.54 100.53
53.66 26.86 0.43 8.82 5.44 0.57 0.40 96.34
55.16 27.53 0.49 8.99 5.71 0.75 0.40 99.08
55.43 26.39 0.49 8.05 5.96 0.84 0.52 97.76
55.86 26.12 0.42 8.11 5.96 0.83 0.56 97.91
58.42 23.54 0.38 5.26 6.99 1.54 0.34 96.56
58.75 23.46 0.38 5.13 7.17 1.80 0.31 97.00
60.39 24.28 0.39 5.15 7.20 1.82 0.50 99.73
59.33 24.67 0.44 5.66 7.15 1.54 0.35 99.26

130

Table 7 (oart’d.) .

Field No. 8102 111203 Feo 1490 C30 N620 K20 T102 MnO BaO Total
era-23
62.88 21.38 0.28 3.66 7.75 2.59 - 0.18 98.72
63.22 21.72 0.34 3.82 7.55 2.31 - 0.09 99.05
62.09 21.53 0.35 3.84 7.54 2.32 - 0.13 97.80
62.45 22.14 0.30 3.99 7.77 2.08 — - 98.73
63.22 21.98 0.31 3.78 7.77 2.31 - 0.11 99.48
62.82 22.48 0.38 4.65 7.91 1.77 - - 100.01
63.14 21.98 0.29 4.00 7.74 2.25 - 0.08 99.48
65.58 19.30 0.73 2.36 6.34 2.45 0.16 0.08 97.00
62.20 22.19 0.38 4.10 8.11 2.35 - - 99.33
62.67 22.42 0.29 4.14 7.90 2.26 - 0.10 99.78
63.86 21.34 0.17 3.20 7.74 3.49 - - 99.80
64.53 21.57 0.13 3.07 8.28 3.11 - - 100.69
64.17 22.11 0.15 3.91 7.71 2.10 - - 100.15
63.25 22.17 0.20 3.87 8.16 2.40 - - 100.05
62.38 21.72 0.30 4.29 7.97 2.07 — 0.13 98.86
64.25 21.08 0.20 2.84 7.46 4.00 - - 99.83
63.51 21.45 0.15 3.40 7.46 3.34 - - 99.31
62.64 21.59 0.11 3.52 7.55 3.36 - - 98.77
63.42 20.99 0.08 2.86 7.52 3.80 - - 98.67
63.36 21.37 0.13 3.24 7.83 3.09 - - 99.02
63.78 21.55 0.17 3.15 7.96 3.53 — - 100.14
63.18 21.02 0.31 3.35 7.63 3.23 — - 98.72
62.76 21.02 0.30 3.14 7.49 3.48 - - 98.19
62.33 22.41 0.32 4.43 7.94 2.05 - 0.12 99.60
62.42 21.74 0.34 3.75 7.64 2.09 - 0.20 98.18
62.23 22.46 0.30 4.14 7.70 2.20 - 0.09 99.12
61.76 22.05 0.36 4.18 7.78 2.14 - 0.11 98.38
61.48 22.62 0.34 4.75 7.89 1.72 - 0.16 98.96
61.47 22.62 0.34 4.76 7.76 1.77 - 0.07 98.79
60.79 22.49 0.34 4.81 7.97 1.86 - 0.15 98.41
62.65 22.16 0.23 4.08 7.98 2.01 - - 99.11
63.28 21.41 0.19 3.67 7.97 2.24 - - 98.76
62.79 21.86 0.21 4.03 8.16 2.27 — - 99.32
62.29 22.21 0.29 4.17 7.69 2.34 - 0.11 99.10
61.45 22.37 0.36 4.83 7.69 1.76 - 0.11 98.57
62.21 21.64 0.28 4.04 7.72 2.64 - 0.07 98.60
62.42 22.36 0.37 4.28 7.77 2.20 - 0.11 99.51
62.17 23.00 0.30 4.67 7.80 1.90 0.06 0.23 100.13
61.01 23.27 0.32 5.34 7.85 1.48 0.06 0.19 99.52
62.41 22.16 0.34 4.25 7.76 2.18 0.06 0.24 99.40
62.36 22.49 0.33 4.35 8.01 2.08 - 0.14 99.76
62.85 22.26 0.27 4.18 7.88 2.31 - 0.09 99.84
60.86 22.56 0.37 4.67 7.54 2.03 - 0.11 98.14
62.42 21.99 0.22 3.96 7.77 2.42 - 0.10 98.88
62.44 21.93 0.36 4.28 7.81 2.23 - 0.14 99.19
62.91 21.79 0.19 3.64 8.11 2.42 - - 99.06
61.97 22.52 0.35 4.25 7.66 2.17 - 0.23 99.15
61.33 23.01 0.36 4.73 7.93 1.92 - 0.29 99.57
61.26 22.27 0.36 4.41 7.97 2.08 - 0.21 98.56

131

hfle7mmU¢L
fiQAhf m0 mo @0 mi go figzmn km find

fifldm.
CPS-1A

102.54
101.92
101.08
100.63
101.28
102.01
100.34
100.81
100.91

336 14M6
222 22 4
000000000
111111100
3352 5180
7.312
898°”8887.7.
43290393
1886.37.5-Jfl
L333l33~h~h

nmw mum
000000000
000000000
2m0 wx7m7

34......333
222222

sanma6 mas
m6 m:a6%$

6.6

CPS-13

36592707900381673711$
97744029417493442946
9 00100011 1010
9mm00000000mmmmm0000m
11111111111111111111

.1 4 0 642 1
..............-.....
00 0 0 0000 0 0
..........-..._......
............_........
77378770 nus/11434551
44244443 034323223
0 0 0 0 0 0 0 0

001000000111111111111
2.1 4 14 55

0 00000000 00
7.7.8—I.~I.6M65888888888888
4&8728868JM680356108
7363.].7. 4..413~I.6~I.7.4..~I.
773777799334333333333

omo onma JJn6 5&8 mm 2JJn

000000000000000000000

M7.19.6.26.5

1711
1232267

.4..Q~84..

222222222222222222222
22176561 565698235
9mm .«I.283~I.3 512173635
0 0 0000 0 0 0
55332333 33333

132

MEmm¢eMflwsof$Mfimu

mue&
fi%Ah%’flfl $9 an mwagp Tszn am fiflfl

Field.Nb.
BBS-10C

57534763222931.3613
41 8434592090513
6563m89999089910
9999 99999099900
1 1 11
12 1003164680018
46.2385998322620
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
32 3323212222233
8
6
.............—..
0
0111
mm uwn 1111mwuw

...-0......00...
00 000000000000

34.32627 13 09196
5256331m—30 335.33

0.......00.0....
8888788888888888
9 60 5292 35 2
4&33“fl4459%fi64m6
............0...
1121544444444444
0928462329296487

8787978777767788
0000000000000000
0000000000000000

17 0.18
11 0.26
45 0.27
19 29 0.26
60 0.31
2 0.23

7
4
12 0.
6
2
4
6
0
77 0

00000000000000
mwnmmmmmmm
312 903327
.AJA .JAJJfiJ
aaaaaaamaa

61.38 20.28 0.20

63 39 20

61.21 20.68 0.25
61 57 20

62 75 20
42

62

BBB-153

98 88
99.56
0.12 99.60
99.34
98.53
99.88
98.69
99.97
0.11 99.34
98.25
98.92
0.09 99.43
100.08
0.09 99.73
0.11 100.03
0.10 99.77
0.11 98.99
99.14
0.14 100.35
0.11 99.68
0.09 98.48
0.16 99.11
98.09
98.16

0.25 4.52 10.17
0.25 4.61 9.84
0.26 4.10 10.29
0.25 4.34 10.37
0.06 0.31 6.07 6.50
0.25 4.21 10.34
0.29 4.69 9.31
0.24 4.07 10.49
0.24 5.48 8.49
0.26 4.52 9.78
0.33 4.39 9.87
0.24 4.23 10.25
0.28 4.29 9.63
0.22 4.20 10.09
0.21 4.14 10.30
0.29 4.73 9.62
0.24 4.18 10.05
0.23 4.25 10.02
0.26 4.14 10.04
0.28 4.24 9.87

98

04

54

32

...
mmfi.Mmmumamflmummmnmwmmflfi
000000000000000000000000
fiflflflfiflfiflfifl$flfiflflflflflflfififlfim
mummmmmmmmmmummmmmmmmmmm
%nmmnumaxmwmxnmmuuummnmu

2%mwmmwwmawmnmmmmma.6mam

101.31
98.82

4.55

0.43

Eflfi-BB

133

Table 8 (cmt’d.) .

agahg no mo mo.mp go fi% mo aw awn

BBB-BB (oont’d.)

Field.NO.

664w6600175320$04u0396
399 0534326538 58 0412
91091890088887098888 8
90090990099999099999m9
11 1 11 1 1
8
o m
........_._.__...._...
0 0
......_._......._.....
..................._..
170 8362 418499 562
«No.9muaawnd99 ~0I~897.989”750
m99999999909999999999m
1%352591 5 5705512253$
5 Qua/.884h7. 5 7.7.4U8584..9—I.8
O O
4544444444444444444444
4600739960653976106288
O O

3343242233222222333332
oooooooooooooooooooo
oooooooooooooooooooooo

2222222222222222222222
0000000000000000000000
wamxmwnnn mm %mnmmm 5w

>muuummmuummmmmmmmmmumm

2&2 smmao an unnmxm o
2““ «22225 aaammasam2ms .2

BBB-1

99.00

0.18 101.77
0.10 97.87
0.11 96.77
0.17 98.94
0.14 99.44

98.08
0.16 99.48
0.08 99.51

0.89

0.70 0.05
0.14

0.

0.82

0.56

111111

14 10.66 0.05

36
17
0

3

4 06 10.80
92

00......
4344444

1606018

.24 4.71 10.34

2
2
2
3
3
3
2
2

0
0
0
0
0
0
0
0
0

no nmn nmmm
0.0.0.0.0.0.000
2mmnmmwmm2
mm msmm2u2

9 313109
8:330.80.5

«mammaas

LWlfiA

99.05

101.37
99.80
0.22 100.03
0.11 97.33

0.08 99.42

554
lasezw

00998008

5 94
9M6
Aududu54..du

1375
“5586.“
nmo.nm0.0.nw

1W2-5

028481562
144220206
188887877
m99999999
B 19
20
.. . . . ._ . .
0 00
...-..__.
...-....—
704995462
312964728
0 O O O O O O O O
99m899998
766176021
874854750
0 I O O O O O O 0
444444445
233222332
552543355
0 O O O O O O O 0
000000000
.........
.E—I.

.....—
00.
32610712
No.620u85J6

0.
23338
981 9
0

““333233.
666666

134
Table 8 (omt'd.) .

Field No. :13”: 1212:3 Feo up can Na20 1:20 T102 MnO BaO Total

IM6(mmfl

7057145852671014
5625728046613196
8655587775678586
9999999999999999
452845 95655 2
222212n12142v . n2
0000000000000 00
........._....._
....._.._._._...
64 5153 99725313
2302 53935539
0....
7998999797888297
6580 00 18534021
.79 .93702584

.0

7392
o o o

5 311 2354 83
flwm3flwm656.. 6557. 47.
000000000.nmo.o.o.0.0.0.

7 476 79 353088
O. .0.... I O.
00nmo.o.o.o.000000000

2 24amu2mmnwmwu4

&l1&1mnmm1ulmmmmm
.mz mammmml .nmma 5m

LLmQaLMK .&&6 $26.99

99.40
0.16 100.35

61660018774
42401654021
99980 9007
990.90%9009”

1 11
1.01 0 5
111 1 1
.. . .. .. ... .
000 0 0
6
0
......... .
0
67656 76
00000. .m0.0
O O O O O 0
00000 000
4 .30 176761
7 85WDM8618J6
O O O O O O
998900—“99m.9 0
1 91
930409
B ““$5657.7.9
0

153612113 63
424..2.1m3nu.4al. 35
3
6

1W4-1B

3105955935439
3343225333332

0.nwo.o.o.nu.nwnmo.0.nmo.nw

wfiamwaww

2.86 101.91
0.54 97.19
0.52 96.19
0.60 96.37
0.39 98.20
0.29 99.04
0.84 99.67
0.19 97.28
0.26 99.19
0.45 99.95
1.02 97.84
0.93 99.11
0.46 95.24
0.38 97.19
1.32 101.49
1.24 96.54
0.87 96.04
0.13 100.97

.81 8.37
.54 8.91
.43 9.49
.13 8.37
.40 8.61
4.63 8.84

4.27 8.76
4.67 8.84

4.53 8.23
4.28 8.39

4.57 9.07
4.50 8.83
4.61 9.28

3 4.37 9.10
4
4
4
5
4

84051152
.7.7877788
O. .0.

6
73

0.64 4.51 9.08
0.96 4.69 8.08
0.71 4.38 8.85

0
0.
0.
0.
0.
0.
0
0
0
0
0
0
0
0

088 0.76
007 0.70

19.61 0.78
62 782 20. 17 0.96
61.44 19. 36 0.20

62.25 19.80 0.72

64.312

62.73 21.80 0.30 0.05 0.81 4.85 8.51

62.97 19.25 0.20
61.81 19.41 0.72
61.87 19.10 0.86
63.72 19.05 0.94
63.95 19.66 0.77
63. 78 20. 21 0.78
62.62 19.45 1.04
63. 72 19.78 0.97
63.47 20. 30 1.45

CPB-ZA

135

Table 8 (curt'd.) .

Field No.

2 7 3 0711 2852477651 603873227635932252095920662
W 8mu5m6un~478R8124465586fl393539480352386994824356317
67776 5898976897870876085 797977657885500901878987
99999m999999999999m999M99mu9999999999999mm9mm999999
6 126 6 60 830002164502546880 4689331356991208545
w 1Mm100%9m53m93331321473579931852237294556545653236
O O O O o O o O O O o 0 O o 0 0 O O O o O o 0 O O O O o o O O O O O O o O O O o O o O o o O O o o o
01101110100101100000000000000000000102222222522222
m__........._.......................__.........._..
oz mmmmw mmwwmmn
i ..._..................._....._......_.............
T 00000 0000000
91 80535649048965 7196 19126 36160205375640 2
0 $8 Hm:7 J5n~2£979170945m2840.0.73122955066976560690w6
O o O O 0 O O O O 0 O O O I O O I O O O O O O O O O 0 O I o O O O 0 O O
”M. 99999999999997.8896988899889998m9988898888888888988
0 225 13352130859545220 30636659790913536890648 60
M2 B437.B.%.8.4..560.4.37.33674=~64Jrl~=~24731A£566691253269742M24
o o o O O O O O o o o O O O o O O o O O o I o O I O o O O
54444444445444444444445445444544444444444444344444
393J4512W.77%6 05510450020$3913&932315730245945 46
w 77697767 £457.7.87.7.87.8 7.57.5 7.98.7.7.8nwnwnwnw7.7.7.7. 7.7.
00000000000000000000000000000000000000000000000000
M. ...._...._.._...................................._
15 42049289980 2456 9:7.30.4..7.2._mmw829 470015 4645380
M 7.7. 7.7.7.2,m7.7.£87.£ 7.7.7.7. 6 445455 44..4 422222 2222222
0
00000000000100000000000000000000000000000000000000
10513540 2 3014 246 7 9 9186 9367357 065 98367
9.“ fi76053711$396364flnn484%9%5$7579$M2590634fi705m~39986
O o O O O O O O O O O O O 0 0 O o o O o O o I O O O O I
0 0 0 0 0 00 0 9 99 9999999999 9
u mmmz m2 m2 omznmz mmmzzmnmmmmz m1 321mmmm121122222291 m1

)

.205514 9 5656 82946 9033 8471.67 59760797696 97731
I O .0.... O. I
212.21.193.14 .12/M333 129m .3333 .12.2 .29033223911211
8 666 66 6666 66666 .eO.“6 “:666 6666 666 65666666566666

CPS-2A (cont’

136

Table 8 (oart’d.) .

fiQAh% no mo m01m§ go fi% mo &m awn

Field.Nb.
CPS-28

7332108 7003079711 36 1.333533825237463 88
08424.61..”2352392591$56$154687800828497(baa/947
999098888889097989098808 8 8 89888
1 1427162 56261643134933 9 39543714.
2u1801800w22234232422394.mn4.88320598. . _.
O O O O O O O O O O O I O I O O O I O O O O O O O O O O O O O O I O O
000011001100101111010000 1.1.0 00112000
...-..............-....._........_.._....
7 087 7 77 87 6 8
...mmmo.....u.wloo.m..om. oo..oommomo..._
O O O O O O 0 O O O O O O O O O O O O O O O
0000 0 0000 0 00 000 0000000
53 323 7192169 6 78 742620139312448 71614
O O O O O O O O O O O O O O O O O O I O O O O O O O O O O O O O 0
0615387372 3732759 84.09 234.9330 62 0972
8w~d78698499 8778878 9895”“669447294999238“

......OOOOOOOOOOO......OOOOOOOOOOOOOIOO
44444444444444.4.44.454444444444555444444444

10072744. 18236550 3 6485149899033065332
“%57788477fls7687887”6&774777422877887334.4.

oooooooocoo...ocoo...oooooooooooooooooooo
00000000000000000000000000000110000000000

61033730315BB48069339 430864084526305 514
JJJJJJJJJJ...JJJJJJJJ.JJJJJJJJJJJJJJJ..JJ
0000000000000000000OOOOOOOOOOOOOOOOOOOOOO
mmmmummmmmmgmmMM$aMmmmsmw.mmfiwmmmmw.mmmfim
m mmmmmmmm mmmmmmmmmnnmmmmmmmmmmnmmmmmmmm

61

uumunn ”manuamnammwwaunmuam “mnflamnuaflmlz

mmmmmmmmmmmmmaawawamwuwuwmaamwaaaamaaawam

CPS-1A

8 102.17
2 102.25
8 101.88
2 101.74
0 100.92

100.69

101.99

0
3
1
4
1

0
0
0
0
0

277360
04.0790”
n0n0010
1 1111
9917736
9290096
34344.34.
1222132
323332.)“
0000000
......-
06
m.1ommn
O O O O O I
0 00000
9502 55
6099“

.2
3

0.. O
mmmmmmm
.3539

«awwmma

11
0
0
2
7

.86

101.27
100.16
100.37
99.31
0.38 99.97
101.73
0.44 102.11
0.10 101.00
0.36 100.36

0.19 102.02
0.13 101.78
0.58 102.34

.07 100.73

10
62

0.27 101.89

T102 MhO BaO Tbtal
0
0
0

5.01 9.22
5.02 9.27

2504.30
653332

00.00....
000000000

137

Table 8 (catt’dd .

0.17 0.19
0.33 0.22
0.14 0.17
19.73 0.24
20.59 0.14
19.56 -
20.13 0.09
19.80 -

19.98 0.20

2
2
2

3.52226
4.30650

.mmwwanmma

fi%)Ah% no mo an my 90

CP3-1A.(cont’

65 98 20.07
66. 28 20.21
66. 34 20.13
66.17 20.17

66. 24)

Field.NO.
CPB-lB
CP3-1D

4 100.91
2 100.56
100.55
100.13
100.50
100.93
100.20
100.83
100.30
100.63
100.07
100.42
100.17

.2
.6
.11
.44

93892683
A330214..2

.0.00.0.00.0.0nu.0.0.nwnU.

0.44 100.19
1.54 100.60
0.43 99.80
1.34 100.44
0.25 100.10

1.27 101.39
0.31 99.91
0. 42 100.41

.90 10.09
.85 10.05
9.49

2 9.57
1 9.47

. 9 9.37

8
9
8

0 4.67 9.71
4
4
4
4
4
4

5

33
40
46
52
62

0.67 5.05 9.02
0.73 5.08 8.76
0.69 4.87 9.28
0.63 4.93 9.53
0.59 4.87 9.37
0.67 4.99 9.39
0.76 5.07 9.09
0.64 4.80 9.47 0.14
0.70 5.02 9.10
0.45 4.72 9.72
0.53 4.80 9.78
0.56 4.83 9.54
0.44 4.76 9.58
0 41 4.61 9.70

0......
0000000

4

1ns.mumuuunmumnm1nmmu

0.nw0000.0.nw0.0.0.0.nw0.nm0.nmnmnwnmnw

2

812345621752 205252
870417253990m0 u020323
O.

mommooooommoooooooooo
2222222222

66 6 3525 010
”627wm2m $:5705m476

mama mama6M6 .a6 6m5aammm

100.92

0.27 4.36 10.54

65.85 19.90

CP1-3A

138

MawmmAmMmsdGhs.

mnem

Field.Nb.

fiQAh% mo mo a0 my go fi% mo &0 mml

BBQ-5C

- 93.80

0.52 3.02 5.00 0.30

68.36 16.39 0.21

BB9-10C

79687644267540299
97198923966890836
34766782542123523
99999999999999999

81 74 5 6

23 11 1 1
............._...

00 00 0 0

13 7 4

65 0 0
_......_.._-.__..

00 0 0
1 418411034185627
2.431433233323343
O O O O I O O O O O O O O O O O
0 000000000000000
6882771731937 70
O O 0 O C O O O O O O O O
66666666666566645
70 6 275735178870

0 o o o o o o o
12222222233233333

2773

nawma ”6665565 5696

000000000000000m0

B M 5 83
0 30
.......-.........
0 0 0 00
400 90 2938555539
2.2.1 £:4..4..Aw1385377
O O O O O O
nwnmlnmnw110.nmnu.nw000010
860 66781808287
.932. .4..4..920159243
O I I 0
606.66 44 44
61356 514 188834
330.83%m3581 .0.—1.7.434
nm0.0. .On6.6.9

BBB-15B

6216540
1826326
6433224
9999999
...—...
73
mm..moo
00 000
75 8
oomomo

0.0.0.0.nmnwnm
739 678
905 947
O O O O O O 0
4545444
7303016
0.318887.
2221122
371 314
434 $54..
I O I
000nm0.0.0.
33
00
._ - _— . .
00

anua us

1nU.0.nan.nU.0.

8852738
3&2A1u4h7.

uuunnun

BBB-3B

70$5581713
05 0439463
5434442385
9999999999
..........
9 7 7

O 0 0

1.. 1. 1.
0 0 0

180 74
101nmmw 01

000mmmmmmm
2 2 61

03%0 90Mm
. O 0 O C O C C O 0
5555444565
8931 1353

880.” 9.9.29.
2112121L31
182

mmOOOOOOOO

5652 5
...-0000.4
0000 0
621 420210
734 777466

cocoon-coo
0000000000

n

106298513
445742748

0 O O O O O O O O I
nunununnnn
70004M5170
JJAJJ.J£A£
4433332203
7777777777

BBB-1

33792
08432
54565
99999
.....
91 6
.01.0
00 0
70068
01100
00000
25425
98900
.0...
44455
94205
81233
.0...
12222
11 78
55fi44
00000
n
1...
0
62 09
65 32
0.. 0
00000
$fi119
695
manna
7 732
0. 333
44454
77777

139

Table 9 (cont/d.).

73.93 12.53 0.84
73.30 12.47 0.59
73.62 12.47 0.65
73.63 12.53 0.58

FieldNo. sicxymzo3 Feo Mgo CaO Nazo K20 T102 MnO BaO Total

8&d(mmfi
1W2-5

91.95
96.50
92.42
94.45
93.08
96.64
96.78
96.28
96.07
95.48
94.20
94.52
92.86
93.77

778
000

.....-........
000

nuunmmnaum
0

coco-coo.
000000000

26

99 0
7 28 0.26

1 593 54 8
9 882 71mg

&m&&m&&mm&&

5
77 6.60 0.24

84 6.36 0.21

“2605031 10
7718242

oooooooooooooo
22232333333322

7
1
0

8802566 764405
3355434u444465
o o o

0.. O. .0....
00000000000000

nu
.00

6%79412
3 54.334

0.0....
0000000

48

3
3

O
0

28 0.52

47 0

mumunmmu

0.0.4.0...
umumluumu
4.21 57288
903 58271
000......
6077 0090
6766 7767

.20 13 89 0.34 0.06

69.10 14.01 0.70

69.05 14 06 0.30
68.39 13.66 0.60

69 25 14
69

95.15
96.27
97.28
93.35

69.85 13.26 0.92 0.07 0.39 2.98 5.79 0.16 0.14 0.09 93.65

70.52 13.44 0.79 0.07 0.36 3.37 6.22 0.17 0.10

95.04
70.92 13.34 0.76 0.07 0.41 3.06 6.49 0.17 0.09 0.13 95.44

92.50
90.19

0.20 93.77
0.13 95.41
0.19 93.97
0.10 95.10

m
.4.4,o 1111oaoav.7.n.9.1.
£5A.AJ££JJA5J
11nu111.1.nvnvnu111111111.
mymmam.ammmmn
finfimfinnuummbfi
«4.9.4Mw.4.1.4mw,o.4.4.1
5.7.0, 1.1.nv o30.1.:. .

I O O O O O O O O O I O
wwammnnnwammw

72.90 13.31 0.85 0.06 0.32 2.75 5.84 0.18 0.06

71.76 13.23 0.85 0.06 0.28 2.64 6.14 0.19
73.47 13.47 0.61 0.06 0.38 2.32 6.81 0.16
69.55 12.97 0.69 0.06 1.15 2.31 6.45 0.17

1W4-lB
CP3-2A

93.95

0.14 93.48
0.19 94.43
0.27 93.42
0.16 94.19

0.18 91.95
93.97

uxuwnmnwnn

o o o o o o o .-

wwwmammwmwmmw

&&&&&&&&&&&

2552721317101

32385568226
coo-0......
33212222332

6394.8 64.16 9
00533 1136M3n

...-.00....
00000000000
86 7
10 0
......-

o o -
0 0

92%
9mm
9mg
9mm
9mm

0.01 93.44

4.17 5.97 0.28 0.02 0.04 94.18

4.13 5.92 0.37 0.01
2.51 5.68 0.30 0.02
3.87 6.07 0.26
3.43 3.98 0.29

4.65 5.41 0.36

.09 1.44 0.01 0.01 1.81 3.25 0.34 0.05

.69 1.30 0.02
.43 1.01 0.02

.71 1.31 0.02
15.12 1.23 0.02

.55 1.07
25
97
36

67.95 14.51 1.24

9.
7.
9.

CPB-ZB

140

Table 9 (omt’d.) .

Field.Nb. si .Al Rec 18;: <21: (3 c: 15. umo Bao Total
CPB-ZB (0:111:35 2°3 "a2 K2 02
68.26 14.65 1.21 - - 4.35 5.78 0.28 0.03 0.03 94.59
67.93 14.66 1.26 - 4.05 5.14 0.27 - 0.01 93.32
67.65 14.74 1.26 0.04 4.27 6.01 0.32 - - 94.30
68.00 14.76 1.20 0.03 4.25 5.11 0.23 - - 93.58
66.74 14.62 1.27 - 4.21 5.84 0.22 0.02 - 92.92
67.82 14.56 1.30 0.01 4.87 5.88 0.38 - — 94.83
67.56 14.76 1.26 0.01 3.24 5.88 0.33 0.06 0.03 93.13
68.18 14.76 1.26 0.03 4.21 5.07 0.32 0.02 - 93.86
67.41 14.49 1.34 0.02 3.62 6.36 0.34 0.04 0.06 93.70
68.50 14.88 1.27 0.02 3.44 5.86- 0.36 — - 94.33
68.25 14.86 1.27 0.04 4.60 5.97 0.37 - 0.02 95.39
74.97 12.81 0.77 - 2.43 5.20 0.06 - - 96.74
75.15 12.92 0.78 0.03 2.32 4.98 - - 0.07 96.74
74.34 12.34 0.81 0.03 2.38 5.26 0.08 - - 95.71
74.43 12.80 0.73 0.03 2.32 5.15 0.11 - - 95.98
74.78 12.70 0.69 0.08 2.40 5.07 0.14 - 0.09 96.41
75.72 12.64 0.80 0.04 2.38 5.22 0.13 - 0.06 97.42
76.35 12.97 0.82 0.03 1.81 5.08 0.05 - - 97.56
75.84 12.45 0.81 0.04 2.32 5.07 0.06 - - 97.08
75.69 12.71 0.65 0.02 2.36 5.20 0.06 - 0.10 97.29
73.14 12.75 0.82 0.03 2.45 5.03 0.07 - - 94.79
74.88 12.80 0.79 0.02 2.41 5.10 0.07 - 0.09 96.65

REFERENCES CITED

REFERENCES CITED

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141

142

Buddingtm, A. F., and D. H. Lindsley, Iron-titanium oxide minerals and
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