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ABSTRACT

UPPER CAMBRIAN AND OLDER ROCKS OF THE
SECURITY—THALMANN NO. 1 WELL,
BERRIEN COUNTY, MICHIGAN

by Gordon A. Yettaw

Clastic rocks older than the Mt. Simon sandstone
have been reported in wells in the Southern Peninsula
of Michigan. The Security-Thalmann N00 1 is the first
well in southwestern Michigan to penetrate the whole
Cambrian section and was reported to have penetrated
over 1,000 feet of arkosic rock below the Mt. Simon.

The problem involved determining the lithology of the
arkosic rock, a study of the Cambrian sequence in this
well, and comparison of these rocks with their equiv-
alents in Wisconsin, northeastern Illinois, and northern
Indiana.

Standard petrographic, mineralogic, sedimentary and
geophysical techniques were used to study the well
cuttings of the Security~Thalmann No. l.

The arkosic rock is a Precambrian granitic gneiss.
The lowermost Cambrian rocks in this well belong to the
Munising formation. In ascending order, they are: Mt.
Simon sandstone - white and hematitic sandstone, Eau
Claire sandstone - glauconitic, sandy dolomite and sand-

stone, Dresbach sandstone - non—glauconitic, dolomitic

Gordon A. Yettaw

sandstone, and the Franconia sandstone - very glauconitic,
sandy and silty dolomite. No Justification for sub-
dividing the Trempealeau formation according to the
Wisconsin classification was found; it is represented

by a slightly cherty dolomite. All the Cambrian forma-
ticnal units in the well may be compared as to their

gross lithology with the standard section of Wisconsin.

UPPER CAMBRIAN AND OLDER ROCKS OF THE
SECURITY—THALMANM N0. 1 WELL,

BERRIEN COUNTY, MICHIGAN

av

11

Gordon A. Yettaw

A THESIS

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

MASTER OF SCIENCE

Department of Geology

1967

ACKNOWLEDGMENTS

The writer is deeply grateful to Dr. C. E. Prouty,
Chairman of the Department of Geology, Michigan State
University, under whose guidance this study was carried
out.

Thanks are extended to Dr. J. W. Trow, Dr. W. J.
Hinze and Dr. R. Ehrlich for their constructive sug-
gestions and critical examination of the manuscript.
Thanks are also offered to G. D. E118 and R. E. Ives of
the Michigan State Geological Survey, for generously
providing the well samples, and information essential
to this study.

Sincere appreciation is extended to the writer's
wife, Joan Yettaw, for typing the manuscript, and for
her encouragement and patience while this paper was

being prepared.

11

TABLE OF CONTENTS

t\ cm} ‘OEII]:Jlt--:‘-JD(.;-IfI EBITS O O O O O I 0 O O O O O O O O O O O I O O O O O 0 O O O O O 0 j- 1
LIST OF FIGURES 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 I O O O O 0 v
LIST OF TABLES O O O O O O O O O O O 0 O O O O O O O O I O 0 0 O O O O O O 0 Vi

IhITRODUCTIOI—bIOOOO0.0.0.0....OOOOOOOOOOOOOOOOOO

GeneralOOOO00....OIOOOOOOOOOOOOOOOOOOOOO

Nature and Scope........................

J: [UFJ l4

LABORATORY PROCEDURES........................

MOdal Analysesoooooooooooooo0.000000coo-
Heavy Mineral Analyses..................
Fragment Size Determinations............
Particle Size and Sorting Estimates.....
Magnetic Susceptibility Measurements....
Mechanical Analyses.....................

REGIODIAL STRUCTUEIOOOOOOOOOO0.0.0.000...O...

K) ~QOVfikntrz-

nEGIONAL PRECAMBRIAN BASEMENT COMPLEX........ 12

EGIONAL STRATIGRAPHY0.0000000000000000000000 15

Jacobsville Sandstone................... 15
Munising Sandstone...................... 15
“qt. Situorl sandStoneOOOIOOOO0.0.0.0000... 16
Eau Claire Sandstone.................... 17
Dresbach Sandstone...................... 19
Franconia Sandstone..................... 22
Trempealeau Formation................... 2M

LITHOLOGY OF THE CUTTINGS.................... 26

Basal Arkosic Interval.................. 26
Mt. Simon Sandstone..................... 36
Eau Claire Sandstone.................... 3

Dresbach Sandstone...................... 38
Franconia sandStOneocoo-0000000000000... 3‘
Trempealeau Formation................... 40

iii

iv

STRATIGRAPHIC IMPLICATIONS or THE
HEAVY MINERALS............................... Ml

ENVIROPIDQEIJT OF DEPOSITION. o o o o o o o o o o o o o o o o o o 0 LL”

CORRELATIONS AND STEATIGRAPHIC
INIPLICATIODTSO0.0.0.0000000.000.000.000.out... 217

SLTBf-LDTARY.0.0.00....000......OOOOOOOOOOOOOOOOO. 249
BIBLIOGPAPHYOOOOOOOOOOOOOOOOO.0.0.0.0...000000 51

APPEI‘IDIX.O0....OOOOOOOOOOOOOOOOOOOOO...0...... 56

Figures

1.

2.

LIST OF FIGURES

Page
Location of the Security-Thalmann
NOO 1VJ6110000OOOOOOOOOOOOOOOOOOOOO0.. 8
Stratigraphic correlations of
Cambrian formations................... ll

Lithologic map of Precambrian surface
of southern Michigan and adjoining
areas.OOOOOOOOOOOOOOOOOOOOOOOOO'00.... In paCICQt

Magnetic susceptibility graph......... 29
Ph‘otomicrographoooo000000..0000000000. 33
Heavy minerals........................ Al

Sub-Trenton section from southeastern
Michigan around the west side of the
Michigan basin........................In packet

Gamma ray-neutron log of Security-

Thalmann No. 1 showing general
lithologic descriptions of units......In packet

V

LIST OF TABLES

Table Page
1. Modal analyses of alteration zones....u 34

2. Modal analyses of the unaltered

zone 5
“V OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

3. Wells reported to have penetrated
the Precambrian in southern

Michigan and adjoining areas........... 63
H. Modal analyses of Precambrian interval.. Tl

vi

INTRODUCTION

General

The Jacobsville sandstone was named by Lane &
Seaman (1907). They applied this term to a red, slightly
arkosic sandstone cropping out in Jacobsville, a small
town in Houghton County, Northern Peninsula of Michigan.
Thwaites (1912) correlated the Jacobsville with the
Bayfield group of Wisconsin (Keweenawan age). Hamblin
(1958) on the basis of an angular unconformity between
the Keweenawan and the Jacobsville in northern Michigan,
dated the Jacobsville as lower or middle Cambrian.
Ostrum (1964) states that a correlation of the Mt. Simon
of Wisconsin and the Jacobsville is obvious on the basis
of lithologic similarity. Cohee (1948) reports that
some deep wells in southern Michigan have penetrated an
arkosic sandstone underlying the Mt. Simon and overlying
Precambrian rock. He questionably correlates this with
the Jacobsville. Two wells drilled on Beaver Island,
Charlevoix County, Michigan, encountered a thick elastic
sequence below the Mt. Simon. Gutstadt (1958) suggests
that possible equivalents of the Jacobsville may be
included in the basal and arkosic portion of the Mt.
Simon sandstone in Indiana. Calvert (196M) states that

most of Ohio is underlain by a basal arkose. Cohee (19M5)

and Fettke (1948) have assigned the name Jacobsville to
135 feet of grayish-red, slightly arkosic sandstone in
a Putman County, Ohio well.

These reports have led many Michigan geologists to
believe sediments older than the Mt. Simon and possibly
Jacobsville equivalent to be present in the subsurface
of southern Michigan.

The Cambrian has not been extensively studied in
the Southern Peninsula. Cohee (1945, 19u7, 1948) has
made a limited regional study of Cambrian rocks, con-
centrating primarily on southeastern Michigan. He is
largely responsible for our present subsurface Cambrian
stratigraphic nomenclature. Pennington (1967) studied
the Cambrian rocks found in the Perry-Wooden No. l,

a well located in Cass County, southwestern Michigan.
Kashfi (1967) is presently studying the Cambrian sequence
of the State-Foster No. 1, drilled in Ogemaw County,
Michigan, east of the present center of the Michigan

Basin.

Nature and Scepe

The Security-Thalmann No. 1 is the first well in
southwestern Michigan to penetrate the full Cambrian
sequence. 0n initial study of the cuttings, this well
was reported to have penetrated approximately 1,000 feet
of possible arkosic sediment underlying the Mt. Simon

sandstone.

The problem of the existance or non—existance of a
thick arkosic sediment below the Mt. Simon sandstone is
a problem of long standing, that is well documented by
the literature. The possible arkosic sediment penetrated
by the Security-Thalmann No. l offered an Opportunity to
study, in detail, the lithologic nature of a reported
arkose to determine if it is a clastic deposit, igneous
rock, or metamorphic rock.

Since this well penetrated the full Cambrian
sequence, it also offered an Opportunity to study the
lithology and stratigraphy of the Cambrian and its
relation to the arkose.

It is heped that a detailed study of the Security-
Thalmann No. l cuttings, using petrographic, mineralogic,
sedimentary and geophysical techniques, may help to
better define the lithology and stratigraphic relation-
ships of the Cambrian and older rocks in southwestern

Michigan.

LABORATORY PROCEDURES

This study was completely of a laboratory nature,
and all work was carried out at the Department of
Geology, Michigan State University.

Drill cuttings from the Security-Thalmann No. 1 and
other wells which were used for this study were generously

furnished by the Michigan State Geological Survey.

Modal Analyses

Modal analyses were done on the basal arkosic
interval of the Security-Thalmann No. 1. Samples of
drill cuttings for the analyses were selected on the
basis of megascopic variation. A small, split portion
of each sample was mounted on a glass slide with Lake-
side "70" and lapped to approximately .03 millimeters
thickness. A polarizing microscOpe and mechanical stage
-were used to identify and count 300 mineralogical points

for each slide.

Heavy Mineral Analyses

At least one heavy mineral analysis was carried out
on each sandstone unit and the arkosic interval of the
well. All heavy mineral separations were done with
tetrabromethane. The 1/8 to 1/16 millimeter size

fraction was selected for heavy mineral study. A

24

polarizing microscope was used for identification of the
heavy mineral grains, and at least 300 grains were counted
fOr each analysis. Because authigenic pyrite often
comprised much of the heavy minerals, it was eliminated
from calculations made in Figure 6, on all but the

granitic gneiss.

Fragment Size Determinations

 

Under the assumption that the lower 1,000 feet of
the Security-Thalmann No. l is a elastic deposit, a grain
size study was carried out on this portion of the well.
For each drill cuttings mount, the long axis of each
mineral species was measured. This method revealed no
significant grain size variation among mineral species.
The length measurements obtained were interpreted to be
a function of grinding by the drill bit and the crystal-
lization size of the mineral Species present. The data,

therefore, are not included in this study.

Particle Size and Sorting Estimates

Suggestions for visually estimating grain size and
sorting were taken from Buschbach (1964).

Measurements of grain size were made with a
binocular micrOSCOpe equipped with a micrometer ocular.
The median grain size was obtained by visualizing the
sample divided into two equal piles; one containing

sizes finer than some Specific grain, and the other

containing sizes coarser than this grain. The measure-
ment of the width of this grain serving to separate the
two piles was used as the median grain size. The
maximum grain size was obtained by measuring the width
of the largest grain found in the sample.

The Wentworth particle size classification was used
for both elastic and carbonate units; and the following

classification for sorting was adopted for this study:

SORTING
Well Sorted - approximately 60 percent of sample
in l Wentworth grade size or less.
Moderately Sorted - approximately 60 percent of sample
in l to 2 Wentworth grade sizes.
Poorly Sorted - approximately 60 percent of sample

in over 2 Wentworth grade sizes.

Magnetic Susceptibility Measurements

 

Magnetic susceptibility measurements were made only
on the arkosic interval of the Security-Thalmann No. 1.
A Model M33 Geophysical Specialties susceptibility
bridge was used for all magnetic susceptibility measure-
ments. Because drill cuttings were used for these
measurements, the following correction was applied to
the apparent magnetic susceptibility to correct for

percent voids:

CORRECTION FOR PERCENT VOIDS

The drill cuttings sample holder is a test
tube of inside diameter (Dc), and has a mark
on it indicating a known volume (V). Drill
cuttings fill the sample holder above this
mark. After completing the magnetic
susceptibility measurement and obtaining the
reading for the apparent magnetic suscep—
tibil ty (2), the sample holder is filled
to the known volume mark with water. The
volume of water required to accomplish this
is (Va).

Let the diameter of the sample well in
the center of the magnetic susceptibility
bridge be (Dsb), and the true magnetic
susceptibility be (MS). Then:

MS : DSb 2 V w\
‘ Dc x vqm x h,

 

 

 

 

 

(IBERRIEN 6 \
47H. .. ,, \\

 

 

 

 

 

 

 

Figure l. - Location of Security-Thalmann No. 1 well,
SE SE SE Section 10, T68, RIYW, Berrien
County, Michigan

REGIONAL STRUCTURE

The Security-Thalmann No. l was drilled on the
southwestern edge of the Michigan Basin and is probably
located on the Berrien anticline, a positive structure
extending northeast from Berrien County toward the cen-
ter of the Basin (Pennington, 1967). To the south and
west of this well 1 es the Kankakee arch, a broad
positive, structural element separating the Michigan
and Illinois basins and connecting the Wisconsin arch to
the Cincinnati and Findlay arches. This arch plunges
gently southwestward from the Wisconsin arch in central
northern Illinois toward the Logansport Sag, a shallow
saddle in north central Indiana. A continuation of
this sag, the Battle Creek trough, extends northeast-
southwest into the Michigan Basin about 40 miles east
of the Security-Thalmann No. 1 (Asseez, 1966).

Based on gravity measurements in northeastern
Illinois, McGinnis (1966) preposes a graben filled with
Mt. Simon sediments, comparable to the Red Sea Rift.
His map indicates an eastward continuation of this
graben into southwestern Michigan.

Structures thought to be present during Cambrian
time are the northeastern Illinois graben (McGinnis,
1966), Findlay and Wisconsin arches (Cohee, 1948),

Berrien anticline and Battle Creek trough (Asseez, 1966),

IO

and the Michigan Basin (Pirtle, 1932).

Precambrian rocks in southwestern Michigan are
contacted at approximately 4,600 feet below the surface
and dip to the northeast toward the center of the basin.
TOpographic relief on the Precambrian surface may be
several hundred feet. This is evidenced by two wells
drilled on Beaver Island. One well reaches the base-
ment at 4,705 feet below sea level; another, only three
miles away, entered the basement at an elevation 700
feet higher (Cohee, 1963).

The top of the Cambrian rocks occurs at about
2,650 feet below the surface in southwestern Michigan.
The Cambrian section is 1,958 feet thick in the Security-
Thalmann N’. l, and also dips to the northeast.

The post Canadian unconformity responsible for
removing the Prairie du Chien rocks in other areas was
not evidenced in this well. In southeastern Michigan,
however, the Cambrian is overlapped by middle Ordovician

rocks (Figure 7).

11

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REGIONAL PRECAMBRIAN BASEMENT COMPLEX

Figure 3 shows the distribution of Precambrian
subsurface lithologies encountered in southern Michigan,
eastern Wisconsin, northeastern Illinois, northern
Indiana, and northern Ohio as reported in publications,
sample descriptions and drillers logs.

Rudman and others (1965) have studied the geology
of the basement in the midwest. They prepared a geo-
chromological map showing isotopic ages of the Precambrian
rocks in the midwest. This map indicates rocks of two
age ranges exist in the area of Figure 3. West of a
line extending from the southwestern tip of Indiana
to the western shore of Saginaw Bay, west of the
"thumb" area in southern Michigan, these rocks are
considered to be part of what Engel, (1963) termed the
central province. Isotopic ages of rock samples from
this area range from 1.2 to 1.5 billion years. Pre-
cambrian rocks east of this line are considered to be
an extension of the Ontario, Grenville province.
IsotOpic ages of rock samples from this area range from
0.8 to 1.1 billion years (Rudman, et a1 1965).

As is illustrated by the figure, the greater pro-
portion of concealed Precambrian rocks in Wisconsin are
igneous and among them, granite predominates. Basalt

flows occur in some areas as do ryolite flows. Thwaites

l2

13

(1931) examined a tube of samples from a water well in
the Wisconsin Dells, that had penetrated a basalt. He
found quartzite and granite below the basalt. Meta-
morphosed sediments are especially common in eastern
Wisconsin. The northern portion of the large area of
metasediments in the figure is called the Fond du Lac
range; the southern portions, the Waterloo range
(Thwaites, 1931). These ranges are primarily composed
of quartzites and Thwaites reports that they are of
Huronian age.

Only seven wells have penetrated the Precambrian in
northeastern Illinois. All were reported as granite or
granodiorite (McGinnis, 1966).

Within the area of Figure 3 in Indiana, there are
three basement wells. The eastern most well penetrated
a dark, purplish—gray augite andesite microporphyry
(Kottlowski, 1953). The other two deep tests were
reported to have encountered granite.

According to Summerson (1962) the Precambrian rocks
of Ohio may be lithologically divided into two groups;
those east of a line from Sandusky Bay to Clermonte
County, and those west of this line. The rocks east
of this line are primarily granite gneiss and ar
associated with the east—sloping side of the Appalachian
geosyncline. Those west of this line are primarily

granites and associated with the Ohio platform.

14

Two prominent liniar gravity trends are present in
southern Michigan. One extends from southeastern
Michigan northwest-southeast into the upper peninsula
and may be genetically similar to the Mid-Continent
gravity "high". The second can be traced from northern
Kentucky to southwestern Michigan (Rudman et a1, 1965).
Rudman and others suggest that these trends may be
caused by basalt flows of Keweenawan type.

Books from only three deep tests in southeastern
Michigan have been petrographically identified; the
first in Washtenaw County - a chlorite schist, the
second in Lenawee County - a granite gneiss (Summerson,
1961), and the third - the granitic gneiss of this
study. A well in Monroe County was also reported to
have encountered a granite gneiss. All other Precambrian
tests were reported to have penetrated granite at the
basement contact. The rocks, that have been identified
by petrographic means, indicate that southeastern
Michigan is underlain by metamorphic rocks probably of

Grenville age.

REGIONAL STRATIGRAPHY

Jacobsville Sandstone

 

The Jacobsville sandstone crops out along the
southern shore of Lake Superior to the east and south-
west of the Keweenawan peninsula of Northern Michigan.
According to Hamblin (1958) the Jacobsville thickens to
the north where it may be several thousand feet thick.
Hamblin describes the Jacobsville as a reddish-brown
mottled sandstone with white streaks, blotches and cir—
cular spots. The sandstone is composed primarily of
round to subangular quartz grains with fresh or slightly
altered feldspar, usually not in excess of 15 percent.

The matrix of the sandstone is quartz and sericite.

Munising Sandstone

 

The Munising sandstone was named for rocks exposed
in bluffs near Munising, Michigan. The Munising in
northern Michigan has been divided into two members;
the Chapel Rock member and the overlying Miner's Castle
member (Hamblin, 1958). These sandstones are exposed
along the northeastern Northern Peninsula west to Pic—
tured Rocks and along an arc south from there. In
southern Michigan, the Munising formation is divided
into four members: Mt. Simon, Eau Claire, Dresbach, and

Franconia (Michigan State Geological Survey, 1964).

15

16

The Chapel Rock sandstone is equivalent to the Mt.
Simon and Eau Claire of southern Michigan (Michigan
State Geological Survey, 1964). At Pictured Rocks, and
apparently throughout Alger County, iichigan, the sand-
stone ranges in thickness from 40 to 60 feet (Hamblin,
1958). According to Hamblin, the Chapel Rock sandstone
is composed almost entirely of quartz, chert, and
quartzite grains with a matrix of small angular quartz
fragments acting as a elastic binder. He states that a
conglomerate is usually present at the base of the
Chapel Rock.

The Miner's Castle member is equivalent to the
Dresbach and Franconia (Michigan State Geologic Survey,
1964). This member constitutes the upper 140 feet of
the Munising formation in northern Michigan (Hamblin,
1958). According to Hamblin, the lithology of the
Miner's Castle is a white, fine— to medium-grained sand-
stone, well— to poorly-sorted and cross-bedded with

occasional conglomerate lenses, shale beds and concretions.

Mt. Simon Sandstone

 

The lithology of the Mt. Simon in southeastern
Michigan is described by Cohee (1948) as a medium- to
coarse—grained sandstone with subangular to rounded
grains and a few beds of sandy dolomite in the upper
part. A study of driller's logs and published

descriptions reveals that the lower part of this member

17

is usually hematitic and slightly arkosic at the base.
Where it is exposed, in western Wisconsin, local beds

of conglomerate and gray, pink or red shale are common
(Twenhofel, et a1, 1935).

In northeastern Illinois, the Mt. Simon consists of
fine- to coarse-grained friable sandstone that is com-
monly poorly sorted and contains very fine pebbles.
Cores show well developed cross-bedding, eSpecially in
the coarser grained beds. Pebbles are larger and more
abundant in the north central part of the state. Red
and green micaceous shale beds occur in the upper part
of the Mt. Simon, but they are not continuous (Buschbach,
1964).

According to Gutstadt (1958) the Mt. Simon of
Indiana is a fine— to coarse-grained sandstone varying
in color from clear to pink, and composed of frosted
and well-rounded quartz grains.

The Mt. Simon sandstone reaches its maximum
thickness in Will County, northeastern Illinois, where
it is approximately 2,800 feet thick (Buschbach, 1964).
The sandstone is 1,040 feet thick in southwestern
Michigan. In southeastern Michigan, Cohee (1948) cites

a thickness of 300 feet for this unit.

Eau Claire Sandstone

 

According to Cohee (1948) the Eau Claire in south-

eastern Michigan consists of sandstone, shale and sandy

18

dolomite, and is locally very glauconitic. The color
of the dolomite or the shale may be gray to dark gray,
pink purple or red to brown. The Eau Claire is sandier
in western and northern Michigan than it is in south-
eastern Michigan. In the Perry-Wooden No. l, Cass
County, Michigan, the Eau Claire consists of a lower
zone of glauconitic, dolomitic sandstone. The middle
zone consisting of siltstone containing abundant dolomite,
muscovite and sandstone. The upper zone is composed of
glauconitic dolomite which is commonly sandy and shaly.
Anhydrite and ypsum were found in the upper and middle
zones of the Eau Claire (Pennington, l967).‘

Twenhofel and others (1935) separated the Eau
Claire in Wisconsin into two zones on the basis of
contained fossils. The lower zone was designated the

Cedaria and the upper the Crepicephalus zone. The

 

Cedaria zone consists of medium—grained sandstones,
interbedded with fine—grained sandstones and siltstones
with occasional beds and laminae containing clay

minerals. The Crepicephalus zone is composed of thin-

 

bedded sandstones and siltstones similar to those of the
Cedaria zone, but glauconite is locally common.

The major lithology of the Eau Claire in north—
eastern Illinois is a fine-grained, well—sorted, glau-
conitic sandstone with shale and siltstone becoming
predominant southward. Dolomite beds and fossil

fragments are common. The contact between the Mt.

 

Simon and the Eau Claire in this area is usually quite
sharp, but in places a transitional zone of coarse-
grained sandstone, interbedded with very fine, silty,
fossiliferous sandstone is present (Buschbach, 195U).

The Eau Claire in Indiana contains three charac—
teristic lithologies: (1) very fine to fine dolomitic
sandstone or siltstone which is usually pink; some beds
contain very abundant glauconite; (2) green, maroon,
and black shale, all glauconitic and micaceous; and (3)
light tan silty or sandy dolomite, some beds being very
glauconitic (Gutstadt, 1958). Gutstadt noted no regular
sequence of these lithologies.

In southwestern Michigan, the writer found 430 feet
of Eau Claire. Cohee (1948) cites a thickness of 250
feet for this sandstone in southeastern Michigan. The
Eau Claire, where it is exposed in Wisconsin, has a
maximum thickness of 125 feet (Twenhofel, et a1, 1935).
In northeastern Illinois, the Eau Claire ranges from

375 to 575 feet thick (Buschbach, 1964). Gutstadt (1958)
reports a thickness of 800 feet for this unit in central

Indiana.

Dresbach Sandstone

The lithology of the Dresbach in southeastern
Michigan is a fine- to medium-grained sandstone with
angular to rounded, frosted and pitted quartz grains;

in some places, the lower portion contains thin beds of

20

white to buff dolomite (Cohee, 1948). In the Perry-
WOoden No. l, the Dresbach sandstone consists of white
and buff dolomitic sandstone which is generally non-
glauconitic, although some glauconite is present near
the lower and upper contacts (Pennington, 1967).

In Wisconsin, the Dresbach is presently considered
a stage including the Mt. Simon, Eau Claire and part of
the Michigan Dresbach equivalent, the Wonewoc formation.
The Wonewoc formation is divided into the Galesville and
Ironton members (Ostrum, 1966). In its outcrop area in
western Wisconsin, the lower limit of the Galesville is
placed directly above the disappearance of the

Crepicephalus fauna. In the subsurface, and where no

 

fossils are present, the lower boundary is put at the
tOp of the highest shaly dolomite or fine—grained sand-
stone. As a rule, the Galesville in Wisconsin is a
medium-grained, rather well-sorted, massive-bedded,
cross-laminated sandstone, and by definition free of
glauconite or fossils (Twenhofel, et a1, 1935). The
Ironton in Wisconsin is ordinarily composed of coarse-
grained, poorly-sorted sandstone becoming progressively
finer and better sorted toward the top. The member is
usually light gray, glauconitic and thick bedded
(Twenhofel, et a1, 1935).

In northeastern Illinois, the Galesville is a fine-
grained, well-sorted, white to light buff, friable,

clean sandstone. Buschbach (1964) split the Ironton

21

into four members. In ascending order, they are:

Buelter - medium-grained sandstone.

Fox Valley - medium-grained to coarse-grained
dolomitic sandstone and sandy dolomite.

Marywood - fine-grained, slightly dolomitic
sandstone.

Mooseheart - dolomitic, glauconitic, coarse-

grained sandstone.

In Indiana, the Galesville alone is considered
equivalent to the Dresbach in Michigan (Gutstadt, 1958).
Gutstadt found the Galesville only in the northwestern
part of the state, where it is a dolomitic sandstone at
the top, grading downward to a sandy dolomite. In the
eastern part of the state, the equivalent of the Dresbach
is not as yet differentiated within the Knox dolomite.
Gutstadt suggests that the lower part of the Knox may
be Cambrian in age. He'describes this portion as a
finely—crystalline to sacchariodal dolomite containing
less than 10 percent chert, glauconite, silt and shale.

Cohee cites 100 feet as the thickness of the
Dresbach in southeastern Michigan. Pennington (1967)
reports 413 feet for this member in Cass County,
Michigan. At its outcrop area in Wisconsin, the
Galesville has a maximum thickness of 75 feet and the

Ironton ranges from 3 to 15 feet thick (Twenhofel,

22

et a1, 1935). In central Illinois, the total thickness
of the Ironton and Galesville is approximately 200 feet
(Buschbach, 1964). Gutstadt (1958) reports a maximum
thickness of 200 feet for the Galesville in western

Indiana.

Franconia Sandstone

According to Cohee (19M8) the Franconia sandstone
of southeastern Michigan is a very glauconitic, fine-
to coarse-grained sandstone composed of angular grains
of quartz and a few beds of dolomite. In the Perry-
Wooden No. l, the Franconia is composed of sandy and
glauconitic, dolomitic siltstone (Pennington, 1967).

In Wisconsin, the Franconia is a stage name
including the Ironton member, the Lone Rock formation
and the Mazomanie formation (Ostrum, 1966). Equivalents
of the Dresbach are the Lone Rock and the Mazomanie.
Berg (1954) divided the Lone Rock formation into four
members on the basis of contained fossils. In ascending

order, they are:
Birkmose - fine-grained, glauconitic sandstone.
Tomah - non-glauconitic interbedded sandstone

and shale.

Reno - wormstones and green sand, highly glau-
conitic and constituting over one half
of the Franconia stage in much of

Wisconsin.

23

Mazomanie - a non—glauconitic dolomitic sandstone
facies of the Reno, in eastern Wisconsin
comprising most of the Reno member.

The Mazomanie was later elevated to formational status
(Ostrum, 1966)

In northeastern Illinois, the Franconia formation
consists primarily of light gray to pink, fine-grained,_
dolomitic sandstone that is almost always glauconitic,
silty, and argillaceous. In the southern half of
northeastern Illinois, however, the lower half of the
formation is sandy, glauconitic, brown dolomite. This
dolomitic facies constitutes the whole Franconia
further South (Buschbach, 196M).

In eastern Indiana, Franconia equivalents are
probably included in the lower part of the Knox formation
described under the Dresbach sandstone. In northwestern
Indiana, Gutstadt (1958) felt justified in using the
term, Franconia, in only two test wells. He based this
application on lithologic descriptions and correlations
from work in Illinois by Workman and Bell (19fl8).

Cohee (19H8) reports that the Franconia in south-
eastern Michigan is 10 to 20 feet thick and in eastern
Wisconsin, he cites a thickness of 140 feet for this
member. Pennington (1967) states that the Franconia is
95 feet thick in the Perry-Wooden No. 1. In west
central Illinois, the Franconia reaches a thickness of

approximately 400 feet (Workman & Bell, 1948).

24

Trempealeau Formation

 

The three members of the Trempealeau formation of
Wisconsin are recognized in places in Michigan. In
ascending order, they are: St. Lawrence, Lodi, and the
Jordan sandstone. Cohee (19MB) described the lithologic
character of the Trempealeau members in southeastern
Michigan. He reports the St. Lawrence member consists
of gray, sandy, very glauconitic dolomite overlain by
dark gray to black dolomitic shale and dolomite; the
Lodi member is generally white to buff dolomite, slightly
sandy, and locally pink; and the Jordan sandstone con-
sists of well-rounded, frosted, and pitted quartz grains.
The Trempealeau of the Perry-Wooden No. l is composed of
glauconitic, slightly hematitic dolomite and dolomitic
sandstone at its base. The rest of the formation con-
sists of dolomite containing oolitic chert in the upper
50 feet. Traces of white soft gypsum were found
throughout the Trempealeau (Pennington, 1967).
Pennington was unable to identify the Trempealeau
members in the Perry—Wooden No. 1.

In Wisconsin, the Trempealeau stage is divided into
the St. Lawrence and Jordan formations (Ostrum, 1966).
Nelson (1956) divided the St. Lawrence into the Black
Earth and Lodi members. The Black Earth member over-
lies the Franconia and is represented by sandy dolomite
and interbedded dolomitic siltstone. It is generally

massive, brown to buff, slightly glauconitic and has

algal structures locally. The overlying Lodi member
consists of siltstone which is generally dolomitic and
dolomitic sandstone (Nelson, 1956).

In northeastern Illinois, the Trempealeau stage is
divided into the Potosi formation and the overlying
Eminence formation (Buschbach, 1964). According to
Buschbach, the Potosi overlies the Franconia and con-
sists of fine-grained dolomite that usually contains
drusy quartz. The lower part of the formation normally
contains some fine sand and glauconite, and a little
glauconite occurs near the tOp. The Eminence formation
is composed of sandy dolomite with beds of sandstone at
or near the base (Buschbach, 1964).

In western Indiana, the Trempealeau was observed in
only two wells. In eastern Indiana, equivalents of the
Trempealeau are probably included in the Knox dolomite
described unde the Dresbach sandstone.

Cohee (1948) reports that the Trempealeau is 500
feet thick in southeastern Michigan. Pennington (1967)
assigned 332 feet to this formation in the Perry—Wooden
No. l, Cass County, Michigan. Buschbach (1964) cites a
range of 140 to 370 feet for Trempealeau equivalents in
northeastern Illinois. In northern Indiana, Cohee (1948)

indicates a thickness of 700 feet.

ITHOLOGY OF THE CUTTINGS

Basal Arkosic Interval

 

The Security-Thalmann No. l was completed in an
arkosic material 1,040 feet below the base of the Mt.
Simon sandstone. There are two possible lithologies
for this interval. One - it is an arkosic clastic
deposit, or two - it is a crystalline igneous or meta-
morphic rock. This section of the paper is devoted to
describing the methods used to determine the lithology
and the results obtained from these methods.

The lower 1,040 feet of the cuttings are composed
of a mixture of moderately altered, granitic mineral
fragments, gray shale, buff limestone fragments, a few
subround, polished quartz grains, and some small sub-
round pebbles of limestone, granite, and quartzite.
Through a comparison with the lithologic units above
the arkosic interval, the writer eliminated the shale,
pebbles, and quartz grains as probable contamination.

A comparison of the gamma ray curve (Figure 8) of
this interval and the Mt. Simon sandstone above it
reveals that the radioactivity is about nine times
greater than that of the Mt. Simon. Extremely high
gamma ray radioactivity, such as this, is common among
igneous and metamorphic rocks. The neutron radiation

level within the Precambrian interval is higher than in

27

any lithologic unit above it. Porosity is commonly
determined by use of the neutron curve and a good rule

of thumb is that highly porous rocks show low neutron
radioactivity, while dense non-porous rocks show high
neutron radioactivity. No evidence oi shale or limestone
beds was found on the gamma ray neutron log.

A large fragment of rock, reported to have been
removed from the drill cuttings at the drilling site,
was studied. The composition, texture, and Optical
properties of this fragment are that of a granitic
gneiss. All rotary samples of the Precambrian interval
were studied megascOpically and microscopically for
sedimentary characteristics. No definite sedimentary
characteristics were found. A complete discussion of
the petrography of the fragment and cuttings will be
given later in this section.

Drilling rates for footage intervals within the
Precambrian were calculated from information recorded in
the daily drilling reports of the Security-Thalmann No.
l. The average drilling rate was 13.9 feet per hour,
but varied from 7.3 to 19.0 feet per hour. A 7 7/8 inch
diameter bit was used in this interval. R. A. Cunningham
of Hughes Tool Company (1967) estimates a range of 5 to
14 feet per hour for the penetration rate of a fresh
granite using a 7 7/8 inch diameter drill bit with 4,200

pounds of weight per inch of bit diameter. According to

Morlan (1965) penetration rates are highly dependent on
the amount of weight being placed on the bit. Cunningham
states that the upper limits on bit weights, now being
used, are in the vicinity of 10,000 pounds per inch of
bit diameter. Bit weight information on the Security-
Thalmann No. l was not available. It would seem quite
possible then, due to the altered nature of the rock
and/or a heavy bit weight, that a penetration rate of 19
feet per hour could be reached.

Drilling rates of separate footage intervals are
included in the descriptive log in the appendix.

Magnetic susceptibility measurements were made on
the granitic portion of the Security-Thalmann No. l as
an added tool to be used in distinguishing granite from
granite wash. Taylor and Reno (1948) studied the mag-
netic properties of granite wash. They cited 50 x 10"6
c.g.s. units as the maximum magnetic susceptibility of
the granite washes they studied. The magnetic suscep-
tibility of 647 granites and related rocks, measured by
Magnolia Petroleum Company, ranged from 3 x 10"6 to
6,527 x 10"6 c.g.s. units. Values greater than
50 x 10"6 c.g.s. would not prove the rock to be a
granite, but would support such a conclusion.

The measurements are presented in Figure 4. As
illustrated by the graph, the values obtained are
extremely variable. This is probably due to a number

of factors; variability in rock composition, amount of

cmfiopEwomnm mo 900 8000 poem CH gamma

 

smwpw thHfinfipaoomzm capocmwz
: mpswfim

{3.2 2r. on; 2.: J: o
O
+ +
.9
+
+ + + + Icon
4
+
+ +
+ + ++ 1000.
4.
I00...—
I000“
I—u

 

loan“

(satun “s '3 'o 9_QI) Aqtttqrqdeosns otqeufiew

shale contamination within the cuttings, iron particles
from the rotary bit, possible errors in instrumentation,
the nature of the samples and because an extremely small
volume of sample was used to determine the magnetic
susceptibilities. Because of the great possibility for
error, these measurements are presented here only to
establish probable bounds within which the true magnetic
susceptibility may fall.

It may be seen from the graph that most of the
values are in a range from 100 x 10"6 to 1,&00 x 10‘6
c.g.s. units, indicating that the true magnetic suscep-
tibility is greater than 50 x 10"6 c.g.s. units.

A small chip of rock, from the Precambrian interval,
studied petrographically, reveals that this rock is a
granitic gneiss, medium-grained, anhedral granular and
shows moderate granulation. Orthoclase, some string
perthitic and grid twinned microcline are the major
feldspars, comprising 43 percent and 12 percent reSpec-
tively. They occur in anhedral, usually fractured or
granulated, grains ranging from 0.07 to 3.6 millimeters
in diameter. Quartz, contributing 28 percent, is
strained. It ranges from 0.05 to 0.47 millimeters in
diameter and occurs as granulation and anhedral grains
surrounded by platy orientated chlorite. Feldspar
fractures and fractures between mineral grains, some as
wide as 0.2 millimeters, are filled with chlorite and

calcite. A minor amount of sericitized oligoclase

31

(AnlS) and a trace of magnetite and zircon were also
found.

Quartz is the dominant mineral of the drill cut-
tings, and on an average constituted 31 percent of the
fragments. Over 50 percent of the quartz contained
tiny, transparent, stubby, rod-like inclusions.

Negative elongation and crystal form indicate that

these are probably apatite. Bubble train inclusions
were present in almost all the quartz. Some inclusions
of chloritic material were present in the highly altered
zones; a full discussion of the highly altered zones
will be given later.

Uniaxial quartz predominated, but in all footage
intervals sampled, biaxial quartz, usually with undulatory
extinction, was found. An increase in the amount of
biaxial quartz was noted within the highly altered
zones.

Feldspars accounted for an average of 37 percent
of the fragments. Orthoclase was the major feldspar and
on an average constituted 27 percent, 3.4 percent of
which was micrOperthitic. Polysynthetically twinned
microcline averaged 8.4 percent. Oligoclase (An13) was
present in amounts less than 1 percent. Almost all
feldspar showed some alteration to sericite and clay
minerals. Oligoclase, in particular, was severly seri-
citized and in some cases, probably identified as seri-

cite. In the altered zones, orthoclase, and to a lesser

extent, microcline were altered to a mass of sericite,
clay minerals, chlorite and calcite.

Biotite and hornblende on an average constituted
8.8 and 2.1 percent of the fragments respectively. In
all footage intervals, both showed some alteration to
chlorite and pseudomorphs after them were common.
Euhedral rutile and zircon were found as inclusions
within much of the biotite and also were found within
a few of the chlorite pseudomorphs.

Chlorite composed from a trace to 18 percent of the
fragments. It was found along fractures and as patches
within orthoclase, microcline, and micrOperthite, as
well as pseudomorphs of biotite and hornblende. Calcite
was often associated with chlorite in the fractures,
but also occurred as isolated fragments and patches
within and associated with the feldspars.

Magnetite, sphene, pyrite, zircon, apatite,
hematite, tourmaline and leucoxene were found in minor
amounts in the modal analyses.

Two highly altered zones were found in the portion
of the granitic gneiss penetrated by this well. The
first is near the total depth of penetration and is 70
feet thick. Moderate alteration exists from this zone
to the total depth and for 15 feet above this zone. The
second is about 50 feet below the Precambrian-Cambrian
contact and is 35 feet thick. Slight alteration extends

to the top of the gneiss and from the altered horizon

33

down for 120 feet.

 

 

l 0 2cmm. J

 

Scale

lain light, showing red

“) highly altered to sericite
lorite showing at the arrow

ed with iron oxide.

Figure 5-“hotomic‘ogr
orthoclase (”
with a patci f
and fractures fi
In the lower alteration zone, feldspars are highly
altered to sericite, clay minerals, calcite and chlorite
(Figure 5) and dense, red, hematitic pigment is present
throughout. Biotite and hornblende are altered to
chlorite. Fractures within feldspars are often sealed
with chlorite, iron oxide, and calcite. In the upper

zone, feldspars were altered to sericite and clay min-

erals; but chlorite was present only as pseudomorphs of

34

biotite and hornblende. The alteration in this zone may
be due to weathering.
Table 1 gives the mineral frequencies found in

both alteration zones.

Table 1. - Modal analyses of alteration zones.

 

 

 

Upper Zone Lower Zone

Quartz 22.7% 27.3%
Orthoclase 46.7% 28.3%
MicrOperthite 3.0% 2.3%
iicrocline 1.0% 8.0%
Biotite - 1.0%
Chlorite 17.7% 11.7%
Sericite 7.7% 15.3%
Oligoclase 1.0% 2.3%
Magnetite .7% 1.0%
Hematite tr. tr.

Zircon tr. tr.

Leucoxene - .3%
Calcite tr. 2.0%
Pyrite - .3%

 

The center of the Precambrian interval is composed
of 455 feet of unaltered to slightly altered granitic
rock. The range of composition within this interval is

on the following page, Table 2.

U)
U1

Table 2. - Modal analyses of the unaltered zone.

 

Quartz 30.0 — 50.3%
Orthoclase 21.0 — 23.0%
Microperthite 2.3 - 7.7%
Microcline 2.7 - 10.0%
Sericite tr. — 5.0%
Biotite 13.0 - 6.3%
Hornblende 2.3 - 5.0%
Chlorite 1.0 - 3.0%
Plagioclase .3 - 1.7%
Calcite .3 - 4.0%
Magnetite .3 - 1.0%
Sphene 00.0 - .3%
Zircon 00.0 - 2.00

\

 

Magnetite and pyrite composed over 40 percent of
the heavy minerals in the gneiss. Magnetite occurs as
irregular grains, sometimes rimmed by a light brown iron
oxide (limonite?). Pyrite was found as irregular grains
usually with a reddish-yellow metallic luster. The red
tint is probably due to a hematitic coating. Zircon
and sphene were the most abundant non—opaque minerals.
They occurred as subhedral and euhedral mineral fragments,
probably crushed in drilling. Some hematite, tourmaline,
and apatite were also found.

The exact genesis of the granitic gneiss could not
be determined from the small fragment of gneiss available.
The gneiss could possibly be a metamorphosed granitic
rock, a granitic rock with primary flow structure, a
granitized sediment, or a metamorphosed sediment. It is

apparent, however, that in the later stages of its

L0
0\

formation the rock was badly fractured. Late hydro-
thermal solutions probably used these fractures as
channels and altered, wherever fractures permitted,
feldspars to chlorite and calcite, biotite and horn-
blende to chlorite, and filled the fractures with
chlorite and calcite.

A complete list of modal analyses may be found in

Appendix A.

Mt. Simon Sandstone

 

In the Security-Thalmann No. 1, 1,040 feet of Mt.
Simon sandstone unconformably overlies Precambrian
granitic gneiss. This member is a sandstone consisting
of clear and frosted, round to angular, quartz grains
and some partings of gray, brown and red shale.

The Mt. Simon varies in color from white to light
red with an increase in hematitic grain coating. In the
lower half, sharp and frequent changes of color are
common. The upper half of the Mt. Simon consists of
190 feet of white sandstone at the tOp, quickly grading
to a hematitic pink sandstone, which is continuous for
260 feet.

The basal 5 feet of Mt. Simon is moderately—sorted,
coarse-grained and has a median grain size of 0.5 milli—
meters and a maximum grain size of 0.8 millimeters. With

this exception, the Mt. Simon is moderately—sorted and

medium-grained with the median and maximum grain size
varying from .3 to .4 millimeters and from 1.4 to .4
millimeters respectively from top to bottom.

The major heavy minerals of the Mt. Simon are
ilmenite and leucoxene. Leucoxene occurs as rounded,
dull, brownish—white grains. Ilmenite is present in
subround to irregular grains, with a purple gray metallic
luster. Zircon is the next most abundant mineral. At
the tOp of the sandstone, it comprised 19 percent of the
heavy mineral suite and increased to 50 percent in the
basal 1/3 of the member. Colorless zircon is the most
common variety, but many grains had a light purplish
hue. Most of the zircon grains are subround with
crystal faces still visible. Tourmaline occurs in
minor amounts as rounded elongate grains. Both the
brown and the indigo varieties are found. Sphene is
present only in the basal 1/3 of the sandstone and

occurs as subround light brown pleochroic grains.

Eau Claire Sandstone

 

The Eau Claire sandstone of the Security-Thalmann
No. l conformably overlies the Mt. Simon sandstone and
is 430 feet thick. The basal portion of the Eau Claire
consists of a light gray, medium-grained, well—sorted,
glauconitic, slightly dolomitic sandstone. Four

characteristics of this basal unit made it easily dis-

medium-grained with the median and maximum grain size
varying from .3 to .4 millimeters and from 1.4 to .4
millimeters respectively from top to bottom.

The major heavy minerals of the Mt. Simon are
ilmenite and leucoxene. Leucoxene occurs as rounded,
dull, brownish—white grains. Ilmenite is present in
subround to irregular grains, with a purple gray metallic
luster. Zircon is the next most abundant mineral. At
the tOp of the sandstone, it comprised 19 percent of the
heavy mineral suite and increased to 50 percent in the
basal 1/3 of the member. Colorless zircon is the most
common variety, but many grains had a light purplish
hue. Most of the zircon grains are subround with
crystal faces still visible. Tourmaline occurs in
minor amounts as rounded elongate grains. Both the
brown and the indigo varieties are found. Sphene is
present only in the basal 1/3 of the sandstone and

occurs as subround light brown pleochroic grains.

Eau Claire Sandstone

 

The Eau Claire sandstone of the Security-Thalmann
No. 1 conformably overlies the Mt. Simon sandstone and
is 430 feet thick. The basal portion of the Eau Claire
consists of a light gray, medium—grained, well—sorted,
glauconitic, slightly dolomitic sandstone. Four

characteristics of this basal unit made it easily dis-

tinguishable from the underlying Mt. Simon: (1) the

Eau Claire is characteristicly glauconitic; (2) secondary
crystallization of quartz makes the grains of the Eau
Claire predominantly angular; (3) the Eau Claire con—
tains a moderate amount of light tan dolo mitic cement;
the Mt. Simon, on the other hand, contains only a small
amount of quartz cement; (4) the Eau Claire, although it
has the same median grain size, (0.3 llimeters ) as the
Mt. Simon, is well-sorted while the Mt. Simon is
moderately sorted.

The amount of dolomite and glauconite within the
basal sand increases upward and the Eau Claire pa s es
to a pinkish tan, hematitic, very finely—crystalline,
glauconitic, sandy dolomite containing some brown, soft,
micaceous shale. The dolomite persists throughout the
remainder of the Eau Claire with the upper 50 feet of
this member being less hematitic.

Irregular to subround grains of ilmenite, colorless
subround zircon, and rounded and etched garnet con~
stituted most of the heavy minerals of the Eau Claire.

A moderate amount of authigenic leucoxene and a few

grains of indigo rounded tourmaline were also found.

Dresbach Sandstone

 

:D

change in lithology from the glauconitic dolomite
of the Eau Claire, to a non—glauconitic, medium—grained

sandstone marks the base of the Dresbach member in the

39

Security-Thalmann No. 1. This member is 131 feet thick.
The lower portion of the sandstone is composed of clear
and frosted, well-sorted, angular to round, quartz

rains showing much secondary crystallization of quartz,
some light tan dolomite, and minor amounts of green-
gray shale. The upper port ion consists of a very dolo-
mitic sar dstclne with a 20 feet thick zone containing

about 30 percent reddish-brown, micaceous shale, occurring

near the top of the member. The median and maximum

q

,rain sizes remain fairly constant throughout the member

'1

l

and range from .2 to .3 millimeters and from .6 to .7
millimeter s respectively from bottom to top.

Colo; less gal net comprised over 40 perc cent of the
heavy m nerals; almost all the grains were etched.
Rounded grains of ilm enite contributed 34 percent.
Green, yellow an d indigo tourmaline were present in
minor amounts, and occurred as well-rounded oval
pleochroic g1 ains. Some zircon and leucoxene were also

found.

Franconia Sandstone

 

The Franconia sandstone overlies the Dresbach and
is 141 feet thick. This member consists of very glau-
conitic, very finely- ~crystalline, sandy dolomite. The
basal portion f this member is light tan; above this,

and extending upwards for 25 feet, the Franconia 1s

42‘:
O

composed of light gray dolomite and gray, very silty
dolomite. The upper portion of the Franconia is a light
gray, very sandy dolomite, becoming brownish red and

less sandy near the tOp.

Trempealeau Formation

 

The tan pink, sandy dolomite lithology of the top
of the Franconia is transitional into the Trempealeau
formation. Because of this transition, the base of the
Trempealeau was estimated by lithologic variation, but
picked specifically on the basis of a decrease in gamma
ray radiation from the Schlumberger gamma ray-neutron
log (Figure 8).

The Trempealeau in the Security—Thalmann No. 1 is
223 feet thick. The lower part of the formation con-
sists of a light tan, slightly hematitic, sandy,
finely-crystalline dolomite, becoming slightly cherty
upward and containing some green-gray and dark gray
shale. The upper portion of the formation is light tan,
slightly hematitic, medium— to coarsely-crystalline,
cherty, dolomite containing some dark gray shale. This
lithology is continuous throughout the Cambrian-
Ordovician contact, making it necessary to pick the tOp
of the rempealeau on the basis of a gamma ray radiation
increase (Figure 8).

The writer found no lithologic units within the

Trempealeau that Justified using member nomenclature.

STRATIGRAPHIC IMPLICATIONS OF THE HEAVY MINERALS

The similarity between the heavy minerals of the
gneiss and those found at the base of the Mt. Simon
(Figure 6) suggest that the gneiss may have acted as a
local source for the basal portion of the Mt. Simon
sandstone. Pennington (1967), Asseez (1967) suggest
that the Berrien anticline was present during Cambrian
time. It is possible that this high furnished a
sediment source for a short period during early upper
Cambrian time. Tyler (1936) reported the heavy minerals
of the Mt. Simon in Wisconsin as being dominantly
ilmenite and leucoxene with zircon and tourmaline
being common. The apparent deficiency of leucoxene in
the Mt. Simon of this study may be explained by con-
sidering leucoxene as an alteration product of ilmenite.

Tyler also studied the heavy minerals of the Eau
Claire. He found zircon, garnet, ilmenite, and leucoxene
to be common to abundant and tourmaline rare. Heavy
mineral frequencies comparable to this were found in
the Eau Claire of the Security—Thalmann No. l.

The Dresbach of this study was found to contain a
simple, well-rounded, heavy mineral assemblage (Figure
6). Such an assemblage indicates multiple cycle
sedimentation. Emrich (1966) noted that the Ironton and

Galesville sandstones in Illinois and Wisconsin, have

41

 

O 10 2O 3O 4O 5O 6O 7O 80 90 100
L L l 1 l 1 1 #4

Dresbach

 

Eau Claire

 

 

Mt. Simon

 

Granitic Gneiss

 

 

 

 

 

 

 

 

I‘ PIC]

Garnet Zircon Leucoxene Tourmaline Sphene

& Ilmenite
'/
%

Hematite Magnetite Pyrite Others

     

Figure 6 — Heavy minerals

2e

well-rounded, simple heavy mineral assemblages. He also
states that the heavy mineral suite of these sandstones
is composed chiefly of tourmaline, zircon, ilmenite,
leucoxene and varying amounts of etched garnet. Only a
small amount of zircon was found in the Dresbach

(Figure 6). However, Emrich found the zircon content

of the heavy minerals within the Galesville and Ironton
may vary from 63 to 2 percent and the garnet content may
vary from zero to 61 percent. The assemblage found in
the Dresbach is within this variability, but is not a
good heavy mineral correlation. It is suggested that
further study be done on the heavy minerals of the
Dresbach in southern Michigan to find out how much the

heavy mineral suite of this member varies.

ENVIROMENT OF DEPOSITION

Assuming that the granitic gneiss of the Security-
Thalmann No. l is the same age as the Precambrian rocks
of southeastern Michigan, it was probably metamorphosed
about 1.2 — 1.5 billion years ago during the Elsonian
Orogeny. It is not known if Precambrian sediments were
later deposited on the gneiss. Occurrences of Pre-
cambrian sediments have been reported in areas adjacent
to the Security—Thalmann No. 1. However, if they were
present, they have been completely removed by pre-
Paleozic erosion.

During early upper Cambrian time, a sea slowly
transgressed into southwestern Michigan. The sea
deposited the Mt. Simon sandstone. During this time, a
part of the granitic body of this study, had topographic
relief and was furnishing clastic material to the Berrien
County area. This high continued to supply sediment

until it was leveled by erosion or buried by the

accumulation of sediment. Concurrent with the granitic

source and throughout the Cambrian, a variety of rock
types, centered around the Canadian shield, were supplying
clastic material (Potter and Pryor, 1961). The sea
transgressed throughout Mt. Simon time, and by Eau

Claire time, waters were slightly deeper and conditions

were suitable for the deposition of carbonates as well

an

as sand. Prior to Dresbach time, the sea regressed
somewhat and the waters became shallow enough for sand
deposition to dolomite. Sand deposition prevailed
throughout Dresbach time. During this time, the with-
drawal of the sea left some areas in northern Michigan

conformity between

U)

exposed. This is recorded by a di
the Chapel Rock and Miner's Castle member (Driscoll,
1959).

By the end of Dresbach time, the sea had begun to
transgress and carbonate deposition was under way. The
sea continued to transgress through Franconia time and
carbonates continued to accumulate forming the Trempealeau.

Gypsum and anhydrite occur in minor amounts in the
Eau Claire, Franconia and Trempealeau of the Perry-
Hooden No. l and the State-Foster No. 1 wells. No
evaporites were found in the Security-Thalmann No. 1.
Both the wells containing gypsum and anhydrite ar
located in structural lows. The Perry-Wooden No. l is
located in the Pattie Creek trough and the State-Foster
No. 1 well occurs low structurally (Pennington, 1967).
Pennington, on the basis of a thicker Trempealeau section
in the Perry-Wooden No. 1, concluded that the Security-
Thalmann No. l was located on a structural high, the
Berrien anticline, and suggested this structural
relationship may have controlled evaporite deposition
by allowing brines, concentrated by evaporation in the

shallower structurally higher area, to flow down slope

46

into the structurally low area. The writer has studied
sample descriptions of all Precambrian deep tests in
southern Michigan. No Cambrian evaporites were reported
in these wells. This indicates that Cambrian evaporite
deposition is of a local nature. It is the writer's
opinion that restriction by Precambr'an highs, sand bars
or other structural features supplied the necessary
enviroments for evaporite deposition during Cambrian
time. This would explain the local nature of these

deposits.

CORRELATIONS AND STRATIGRAPHIC IMPLICATIONS

Gamma ray correlations of sub-Trenton rocks from
Beaver Island, Charlevoix County, Michigan, to south-
eastern Michigan are as shown in Figure 7. Because few
wells that penetrate the Cambrian in this area are
logged, the correlations into Wisconsin and t e Northern
Peninsula of Michigan were made on the basis of well
descriptions by Cohee (19MB) and Dixon (1961).

In the Northern Peninsula of Michigan and in
Wisconsin the Trempealeau formation may be subdivided
on the basis of lithology, into the Jordan, Lodi, and
St. Lawrence members (wells 2 and 3). In the Southern
Peninsula these units are usually part of a dolomite
sequence and the Trempealeau may not be subdivided. In
Indiana (well 5) the Trempealeau is part of the Cambrian-
Ordovician Knox Dolomite and the boundary between the
two systems can not be picked on the basis of lithology
(Gutstadt, 1958) or gamma ray curve characteristics
(well 5). Gamma ray curve characteristics have been used
by Pennington (1967) to correlate sub—Trenton rocks from
southwestern Michigan to northwestern Ohio, but he by-
passed Indiana.

The Franconia, Dresbach, and Eau Claire may be
correlated into the Northern Peninsula of Michigan,
western Wisconsin and northern Indiana by gamma ray-

neutron logs and sample descriptions. But the actual

47

contacts between these members can not always be
defined.

The Mt. Simon is the most consistantly correlatable
unit of the Cambrian system. This member has been
traced throughout southern Michigan, Wisconsin, Illinois,
Indiana, and Ohio by various workers.

A slightly arkosic sandstone older than the Mt.
Simon was found in the State-Beaver Island No. 2 well
(well 5, Figure 7). Over 800 feet of this unit were
penetrated in the State-Beaver No. 1 well drilled three
miles north of well 5. It is suggested that further
work be done on this unit to determine its age and

relationship to the Cambrian section.

SUMMARY

The Security-Thalmann No. l penetrated 1,0AO feet
of Precambrian moderately granulated, granitic gneiss.
The lowermost Cambrian rocks in the well are
members of the Munising formation. The basal member is
the Mt. Simon sandstone. It is composed of 1,0AO feet

of white and hematitic, moderately-sorted sandstone.

The Eau Claire member is #30 feet thick. It consists

of pinkish-tan, glauconitic, sandy dolomite and a basal
well-sorted, glauconitic, dolomitic sandstone. The
Dresbach member is composed of 131 feet of non-glauconitic,
well-sorted, dolomitic sandstone. The Franconia member

is 141 feet thick and consists of very glauconitic,

sandy and silty dolomite.

The Trempealeau formation is composed of 223 feet
of light tan to slightly hematitic, slightly cherty
dolomite. No justification for using Trempealeau member
nomenclature was found.

The wide-spread Post-Canadian unconformity is not
evidenced in this well, but is present in southeastern
Michigan, along the Findlay arch.

The upper Cambrian sandstones of the Security-
Thalmann No. 1 may be correlated with upper Cambrian
sandstones of Wisconsin on the basis of heavy minerals.

However, further study of the heavy minerals of the

119

50

Dresbach is needed to make a definite heavy mineral
correlation between the Dresbach and its proposed
Illinois and Wisconsin equivalents, the Galesville and
Ironton sandstones.

Correlations of the upper Cambrian rocks of
southern Michigan, with those of northern Michigan,
Wisconsin and Indiana, were made through use of well
descriptions and gamma ray-neutron logs. A slightly
arkosic sandstone, penetrated below the Mt. Simon in
the State-Beaver Island No. 2 well, was tentatively put
in the Cambrian System. Further study of this unit is

recommended.

BIBLIOGRAPHY

Adams, J. and Rhodes, M. (1960) Do i t .
Seepa,g e Refluxion, Bull. of A. A. P. G., Vol. Ah,
pp. 1912-1920.

Asseez, Y. (1967) Stratigraphy and Paleogeography of
the Lower Mississippian Sediments of the Michigan
Basin, Ph.D. thesis, Michigan State University.

Atwater, G. I. and Clement, G. M. (1935) Pre-Cambrian
and Cambrian Relations in the Upper Mississippi
Valley, Pull. of G. s. A., Vol. pp. 1659—1686.

Berg, R. R. (195M) Franconia Formation of Minnesota
and Wisconsin, Bull. of G. S. A., Vol. 65, pp.
857-882.

Bieberman, D. F. (19U9) Stratigraphy of Three Wells
r Sullivan and Vigo Counties, Indiana, Rpt. of
g. No. 2, Ind. State Geol. Surv.

Bradbury, J. C. and Atherton, E. (1965) The Precambrian
Basement of Illinois, Ill. Stat e Geol. Surv.,

Pusc h.bach, T. C. (196%) Cambrian and Ordovician S rata
of Northeastern Illinois, Rpt. of Inv. No. 219,
111. State Geol. Surv.

. (1965) Deep Stratigraphic Test Well Near
Rock Island, Illinois, 111. State Geol. Surv.,

och
JIM

 

Ciro. .

Calvert, W. L. (1962) Sub—Trenton noc fits from Lee
County, Virginia to Fayette County, Ohio, Rpt. of
Inv. No. A5 Ohio Geol. Surv.

 

t Virginia and Pennsylvania to

(1363) Sub- Trenton Rocks of Ohio in Cross-
o Inv. No. U9, Ohio Geol. Surv.

’64) (n

. (196Aa) Pre—Trenton Sedi mentaticn and Dolo-
mitization, Cincinrati frch Pro n.ce: Theoretical
Considerations, Bull. of A. A. F. G., Vol. #8,
pp). 166- 1.90.

 

52

(196Mb) Sub-Trenton Books from Fayette
ounty, Ohio to Brant County, Ontario, Rpt. of
nv. No. 52, Ohio Geol. Surv.

 

C
I

.Cohee, G. V. (1955) Lower Ordovician and Cambrian

Rocks in the Michigan Basin, Michigan and Adjoining
Areas, U. S. Geol. Surv. Oil and Gas Inv.

(Prelim.) Chart No. 9.

. (19M?) Cambrian and Ordovician Rocks in
Recent Wells in Southeastern Michigan, Bull. of
A5. A. P. Go, V01. 31, pp. 293-3070

 

. (l9u8) Cambrian and Ordovician Rocks in
Michigan Basin and Adjoining Areas, Bull.
A

 

'.

. P. G., Vo1. 32, pp. 1u17-1uu8.

. (1965) Geologic History of the Michigan
Basin, J. of Wash. Acd. of Sci.

 

Cunningham, R. A. 1967) ersonal correspondence.

Dapples, E. C. (19MB) Tectonic Control of Lithologic
Associations, Bull. of A. A. P. G., Vol. 32, pp.

Dawson, T. A. (1960) Deep Test Well in.Lawrence County,
Indiana: Drilling Techniques and Stratigraphic

Interpretations, Ppt. of Prog. No. 22, Ind. State
Geol. Surv.

, et a1. (1960) Catalogue of Well Samples of
the Indiana Geological Survey, Geol. Surv. ir.
No. 8, Ind. Dept. of Cons.

 

Dixon, R. A. (1961) Lithologic Study of a Cambro—
Ordovician Core Delta County, Michigan, M. S.
thesis, Michigan State University.

Dobrin, M. B. (1963) Introduction to Geophysical
PrCSpecting, AcGraw Hill Book Co., Inc., New York

Driscoll, E. G. (1959) Evidence of Transgressive-
Regressive Cambrian Sandstone Bordering Lake
Superior, J. of God. Pet., Vol. 29, pp. 5—15.

Ekblaw, G. E. (1938) Kankakee Arch in Illinois, Bull.
of G. S. A., Vol. 49, pp. 1428.

Emrich, G. H. (1966) Ironton and Galesville (Cambrian)
Sandstones in Illinois and Adjacent Areas, Ill.
State Geol. Surv., Circ. M03.

Farkas, S. E. (1960) Cross-Lamination Analysis in the
Upper Franconia Formation of Wisconsin, J. of Sed.
Pet., Vol. 30, pp. HU7-u58.

Fettke, C. R. (19MB) Subsurface Trenton and Sub-
Trenton Rocks in Ohio, New York, Pennsylvania
and W st Virginia, Bull. of A. A. P. G., Vol. 32,
pp. 1u57-1492.

. (1961) Well-Sample Descriptions in North-
western Pennsylvania and Adjacent States,
Pennsylvania Geol. Surv., Bull. No. MAO.

 

GeOphysical Specialties Company (1963‘ Magnetic
Susceptibility Bridge, Model MS-3 Inst. Man.

Graham, w. A. P. (1933) Petrology of the Cambrian-

Ordovician Contact in Minnesota, J. of Geol., Vol.
Ml, pp. h68-M86.

Grogan, R. M. (19M-) Present State of Knowledge
Regarding the PreCambrian Crystallines of Illinois,
111. Acad. of Sci. Trans., Vol. “2, pp. 97-102.

Gutstadt, A. M. (1958) Cambrian and Ordovician Stra-
tigraphy and Oil and Gas Possibilities in Indiana,
Geol. Surv. Bull. No. 1&.

Hamblin, w. K. (1958) Cambrian Sandstones of Northern
Michigan, Mich. State Geol. Surv. Publication 51.

Howell, B. F., et a1. (19uh) Correlation of the
Cambrian Formations of North America, Bull. of
G. S. A., Vol. 55, Pp. 993-1003.

Ives, R. E. (1967) personal communication.

Johannsen, A. (1932) Descriptive Petrography of the
Igneous Rocks, Univ. of Chicago Press, 111.

Kashfi, M. (1967) The Upper Cambrian Section of the
State Foster No. 1 Well, Ogeman County, Michigan,
M. S. thesis (in preparation), Michigan State
University.

5M

Kottlowski, F. E. and Patton, J. B. (1953) Pre-Cambrian
Rocks Encountered in Test Holes in Indiana,
Proceedings of the Indiana Acad. of Sci. for 1952,
Vol. 62, pp. 23u—Ofl3.

Krumbein, W. C. and Pettijohn F. J. (1938) Manual of
Sedimentary Petrography, Appleton-Century—Crofts,
Inc., New York.

. and Sloss, L. L. (1956) Stratigraphy and
Sedimentation, W. H. Freeman & Company, California.

 

Lockett, J. R. (19u7) Development of Structures in
Basin Areas of Northeastern United States, Bull.
of A. A. P. G., Vol. 31, pp. Meg-uu6.

Lovering, T. S. (1949) Rock Alteration as a Guide to
Ore-East Tintic District, Utah, Economic Geology,
Monograph l.

McCormick, G. R. (1961) Petrology of Precambrian Rocks
of Ohio, Rpt. of Inv. No. 41, Ohio State Geol.
Surv.

McGinnis, L. D. (1966) Crustal Tectonics and Precambrian
Basement in Northeastern Illinois, Rpt. of Inv.
No. 219, Ill. State Geol. Surv.

Michigan State Geological Survey, 196M, Stratigraphic
Succession in Michigan, Mich. Geol. Surv. Chart
No. 1.

(1965) Tests Reported to have Penetrated
Basement Rocks in the Southern Peninsula of
Michigan.

 

Milner, H. B. (1940) Sedimentary Petrography,
Nordeman Publishing Company, Inc., New York.

Torlan, E. A. Designing Large Diameter Hole Drilling
Programs, World Oil (April 1962).

Nelson, C. A. (1956) Upper Croixan Stratigraphy, Upper
Mississippi Valley, Bull. of G. S. A., Vol. 67,
p’po 165-1él".

Ockerman, J. W. (1930) A petrographic Study of the
Madison and Jordan Sandstones of Southern Wisconsin,
J. of Geol., Vol. 38, pp. 3H6-353.

55

Ostrom, Me. E. (1966) Cambrian Stratigraphy of
Western Wisconsin, Michigan Basin Geol. Soc.
Annual Field Conf., Inf. Circ. No. 7.

Pennington, E. K. (1967) A Stratigraphic Study of the
Upper Cambrian of the Perry-Wooden No. 1 Deep
Test Well, Cass County, Michigan, M. S. thesis,
Michigan State University.

Pettijohn, F. J. (l9u9) Sedimentary Rocks, Harper and
Bros., New York.

Pirtle, c. w. (1932) Michigan Structural Basin and its
Relationship to Surrounding Areas, Bull. of
A. A. P. G., Vol. 16, pp. 1A5-152.

Potter, P. E. and Pryor, w. A. (1961) Dispersal
Centers of Paleozoic and Later Clastics of the
Upper Mississippi Valley and Adjacent Areas,
Bull. of G. S. A., Vol. 72, pp. 1195-1250.

Rudman, A. J., et a1. (1965) Geology of Basement in
Midwestern United States, Bull. of A. A. P. G.,
‘7010 “'9’ pp. 89u-9040

Schwartz, G. M. (1952) Chlorite-Calcite, Pseudomorphs
fter Orthoclase Phenocrysts, Ray, Arizona,
Econ. Geol., Vol. 47, pp. 655-674.

Stauffer, C. R. (1925) The Jordan Sandstone, J. of
G601.) V01. 33’ ppo 699-7130

Summerson, C. H. (1962) Precambrian in Ohio and
Adjoining Areas, Rpt. of Inv. No. AH, Ohio Geol.
Surv.

Taylor, G. L. and Reno, D. H. (1948) Magnetic Properties
of "Granite" Wash and Unweathered "Granite",
Geophysics, Vol. 13, pp. 163-181.

Templeton, J. S. (1950) The Mt. S mon Sandstone in
Northern Illinois, I11. Acad. of Sci. Trans.,
v01. 143, pp. 151-1590

Thwaites, F. T. (1923) The Paleozoic Rocks Found in
Deep Wells in Wisconsin and Northern Illinois,
Jo Uf G801o, V01. 31’ pp. 529-5550

. (1931) Buried Pre-Cambrian of Wisconsin,
Bull. of c. S. A., Vol. 42, pp. 719—750.

 

56

Trowbridge, A. C. and Atwater, G. I. (193 A)
Stratigraphic Problems in the Upper Mississippi
Valley, Bull. of G. S. A., fol. MS, pp. 21-80.

Twenhofel, W. H., et al. (19 35) Cambrian Strata of
Wisconsin, Bull. of G. S. A., Vol. #6, pp. 1687—
17AM.

Tyler, S. A. (1936) Heavy Minerals of the St. Peter
Sandstone in Wisconsin, J. of Geol., Vol. 6,
Pp. 55—84.

Walcott, C. D. (191H) Cambrian Geology and Paleontology,
Smithsonian Misc. Coll., Vol. 57. pp. 3A5-412.

v

Wasson, I. B. (1932) Sub—Trenton Formations in Ohio,
u. of

Ge 01., V01. HO, pp. 673- 687.

Whiting, W. M. (1965) A Subsurface Study of the Post-
Knox Unconformity and Related Rock Units in
Morrow County, Ohio, M. S. thesis, Michigan State
University.

Wilgus, W. L. (1933) Heavy Minerals of Dresbach
Sandstone of Western Wisconsin, J. of Sed.
Pet., Vol. 3, pp. 83-91.

Willman, H. B. and Payne, J. N. (1912) Geology and
Mineral Resources of the Marseilles, Ottawa and
Streator Quadrangles, 111. State Geol. Surv.
Bull. No. 66.

Wilmarth, M. G. (1938) Lexicon of Geologic Names
(including Alaska), . S. Geol. Surv. Bull.
No. 896.

Workman, L. E. and Bell, A. H. (19GB) Deep Drilling
and Deeper Oil Possibilities in Illinois, Bull. of
A. A. P. G., Vol. 32, pp. 2041—2062

 

APPENDIX

Detailed descriptive log of the Cambrian system of the
Security-Thalmann No. 1 well.

Cambrian System
St. Croixan Series
Lake Superior Group

Trempealeau Formation (223')

Thickness Depth to
top
(Feet) (Feet)

Dolomite, tan, medium- to coarsely- 40 2635
crystalline, very cherty (oolitic),

slightly hematitic, trace of drusy

quartz and drusy calcite; some shale,

dark gray, dolomitic.

Dolomite, tan, medium- to coarsely- 5 2675
crystalline, cherty, slightly hema-

titic, trace of drusy quartz and

drusy calcite; some shale, dark

gray, dolomitic.

Dolomite, tan, medium- to coarsely- 10 2680
crystalline, slightly cherty,

slightly hematitic, trace of drusy

quartz and drusy calcite; some shale,

dark gray, dolomitic.

Dolomite, tan, medium- to finely- 25 2690
crystalline, slightly cherty, and

hematitic; shale (lo-20%), dark gray

to green gray; trace of pyrite.

Dolomite, tan, finely-crystalline, 30 2715
trace of pyrite; shale (5-10%),

green gray, dolomitic and reddish

brown, soft.

57

58

Dolomite, tan and hematitic pink,
finely-crystalline, trace of drusy
quartz; a few quartz grains round to
subround, pink, frosted; shale (5-
20%), green—gray and dark gray,
dolomitic.

Munising Formation
Franconia Sandstone Member (lhl')

Dolomite, brownish red (hematitic),
very fine to finely-crystalline,
glauconite inclusions; some grains
frosted; few pieces of pyrite.

Dolomite, light gray, very finely-
crystalline, much included glauco-
nite; sand grains (20-M0%), angular
to subround, median grain .3mm, max-
imum grain .5mm, moderately-sorted;
trace of pyrite.

Dolomite, dark gray, silty, very
finely-crystalline, much included
glauconite; sand grains (30%), angu-
lar to subround, median grain .3mm,
maximum grain .5mm, moderately-
sorted; trace of pyrite.

Dolomite, light tan to tan, very
finely-crystalline, glauconitic;
trace of pyrite; some sand grains,
angular to round, frosted.

Dresbach Sandstone Member (131')

Sand, white, angular to round,
medium—grained, well-sorted, clear
and frosted, very dolomitic; some
secondary crystallization of quartz,
median grain .Hmm, maximum grain
.7mm.

Sand, as above, but 30% shale, reddish

brown, micaceous.

Thickness
(Feet)

12

53

A0

25

15

no

Depth to
top
(Feet)

2845

2960

2985

3000

3040

59

Thickness Depth to
top
(Feet) (Feet)

Sand, white, medium-grained, clear 76 3060
and frosted, well-sorted, angular to

round, slightly dolomitic, much

secondary crystallization of quartz,

median grain .3mm, maximum grain .6mm.

Eau Claire Sandstone Member (A30')

Dolomite, dirty brown to gray, very 59 3136
finely-crystalline, much glauconite,

sandy; shale, dark brown, slightly

micaceous; trace of pyrite.

Dolomite, pinkish tan, hematitic, 225 3195
very finely-crystalline, glauconitic,

sandy; shale, green—gray, dolomitic;

shale, brownish-red, micaceous, soft,

dolomitic.

Sand, gray-white, some frosted, 1H7 3M20
medium-grained, angular to subround,

well-sorted, dolomitic (light tan),

slightly glauconitic; trace of py-

rite, much secondary crystallization

of quartz, median grain .3mm, maximum

grain .6mm.

Mt. Simon Sandstone Member (1,0M0')

Sand, white, frosted and clear, medium- AB 3567
grained, moderately-sorted, round to

angular, very little secondary crys-

tallization of quartz, median grain

.3mm, maximum grain .GOmm; shale

(20%), brown-black, soft, Shiny,

dolomitic.

Sand, as above, but shale (15%). 100 3615

Sand, as above, but pure and white, 30 3715
subangular to round.

Sand, as above, but hematitic pink; 260 37n5
shale (10%), green—gray, soft,
dolomitic.

Sand, as above, but white. U5 M005

60

Thickness Depth to

top

(Feet) (Feet)
Sand, as above, but hematitic. 10 A050
Sand, as above, but white. 60 A060
Sand, white, frosted and clear, 5 A120
medium-grained, moderately-sorted,
round to angular, very little sec-
ondary crystallization of quartz,
median grain .AOmm, maximum grain
1.A0mm; shale (10%), green-gray,
soft, dolomitic.
Sand, as above, but hematitic. 35 A125
Sand, white, frosted and clear, A0 A160
medium-grained, subround to angular,
moderately-sorted, median grain .AOmm,
maximum grain .85 mm; shale (30%),
red, soft, micaceous.
Sand, as above, but no shale. 35 A200
Sand, as above, but slightly hema- A0 A235
titic; some shale, red as above; and
shale green, dolomitic.
Sand, as above, but white. 50 A275
Sand, as above, but hematitic. 5 A325
Sand, as above, but white. 10 A330
Sand, as above, but hematitic. 6O A3A0
Sand, as above, white, and no shale. 10 AAOO
Sand, as above, but hematitic. 25 AAlO
Sand, as above, but slightly hema- 10 AA35
titic; some Shale, green gray.
Sand, as above, but no shale. 30 AAA5
Sand, as above, but some shale, 5 AA75

green-gray.

61

Thickness Depth to
top
(Feet) (Feet)

Sand, as above, but white, and no 20 A580
shale.

Sand, slightly-hematitic, coarse— 6 A600
grained, moderately-sorted, frosted

and clear, median grain .50mm, maxi-

mum grain .80mm; trace of shale,

green and brown; trace of feldspar.

Precambrian System
Granitic Gneiss (1,0A0'

V

J-
0\
C.)
O\

Granitic gneiss; orthoclase and 60 A
microcline, orange and white, fresh
to dense white with pink mottling;
quartz fragmental, clear, some yellow,
when associated Mibh biotite and/or
feldspar is in an interlocking
crystal arrangement; books of bio-
tite, green-black, fresh, shiny

black.

Granitic gneiss; microcline and 35 A660
orthoclase, primarily dense reddish-

brown to light orange; a few feld-

spar fragments highly altered to

dense white with pink mottling; some

books of green-black biotite; quartz,

clear, fragmental splinters; some

chlorite.

Granitic gneiss; orthoclase and 216 A695
microcline, mostly white, some light

orange, some dense white feldspar;

books of greenish-black biotite;

(A 00 to £710 highly contaminated

wi h Ellswort Shale and Trenton

Limestone.

Calculated drilling rate from A703 to A736, 7.3 feet per hour.

0\
P0

Granitic gneiss, feldspar, primarily
white, ome fragments of orar .ge feld-
spar; some dense white, altered;
books of black, shiny biotite;
quartz, clear fragmental, (5100 to
5135, 52A0 to 5260 and 53A5 to 375)
highly contaminated with EllSVVUPth
Shale and Trenton Limestone; (5260 to
320) contains a few water polished
s-and grains (P1 eis ocene?).

y

from A976 to
from 5202 to

Calculated drilling rate

Granitic gneiss; feldspar, 70% white

and 30% pink; black, pearly books of
biotite, some ferruginous; quartz,
clear, fragmental.
Calculated drilling rate from 5266 to
Granitic gneiss; feldspar, reddish-
oran e; quartz, clear, ye low and

ed, fragmental; biotite, green-

black to green; some chlorite.
alculate d drilling rate frcm 5A37 to

Granitic gneiss; feldspar, 70% white
and 30% pink; pearly black and
greenish books of biotite; quartz,
clear to yellow, fragmental.

Calculated drilling rate from 5567 to

Total Depth

Thickness

(Feet)
360

1A.0

70

5550, 15.A

Depth to

top

(Feet)

A915

hour.
hour.

hour.

hour.

feet per
feet per
5375
feet per
5A60
feet per
5530
feet per
56A7i

3
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