.4- viz. 1. 599s n A. *w. w é .1 \4: ‘~ I u cm a\» :. ' ..~. m. tffié'x‘ 1. .. w,” - J... ..,. (1 l:' —v‘ {V a v. “$.73” >35." 6.. ‘3. ‘fi... 6%"..1. .M‘J; " ~ “ . “‘3 57. v": ~ w-fi .Q'I “.._ z“ . é ‘ ‘ v‘.‘ m :. 4“}. w‘ ‘ .r ‘ '3‘. c i, a. .363 Sgt...“ 41:1:1 ‘D:>v-I0‘ {I Wfi‘i‘v.‘ 4&3}. ~‘ ' z ..., ~..__.‘ “ ":1 a ' J; ‘9'" ‘7‘. a ‘ 4 mi‘ I u , go .’:..“"‘-.<’xt: ’03?! I ‘3 .5? 1%: \ l a; Mo. A». .u.. i. fir? 3 ‘9..- ‘“ y... -W -. a§4w 4‘57..v »~.- "' .W‘-.. "‘. ...~.- . .»a. .u .1. ~.-,..- A sm/ LI IBRARIES WWWWWWWWWWWWWWWWWWWWWWWWWWWWWW WWWWWWW WWWWW WWW 30’ LIBRARY Michigan State Unlverslty | This is to certify that the thesis entitled CRYSTAL SIZE DISTRIBUTION COMPARISON IN ORDOVICIAN DOLOMITES presented by ROBERT CRAIG BROWN has been accepted towards fulfillment of the requirements for MASTER degreein SCIENCE Major professor 0-7639 MS U is an Affirmative Action/Equal Opportunity Institution W ”GENREWRNBOXtor-MMMMMMWM W To AVOID FINES Mum on or bdon mm. W DATE DUE DATE DUE DATE DUE W MSU I. An mm Action/Equal OW lm WM‘ CRYSTAL SIZE DISTRIBUTION COMPARISON IN ORDOVICIAN DOLOMITES by Robert Craig Brown A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Geological Sciences 1994 ABSTRACT CRYSTAL SIZE DISTRIBUTION COMPARISON IN ORDOVICIAN DOLOMITES By Robert Craig Brown Crystal size distributions (CSDs) vary according to nucleation and growth. CSDs are compared within and between the Trenton Formation (Middle Ordovician) and the Saluda Formation (Upper Ordovician) dolomites, and to theoretical models (site-satura- tion, Johnson-Mehl). Comparisons are made by 1) t-test of standard deviations of nor- malized CSDs, 2) Kolmogorov-Smimov goodness-of-fit (K-S) test between CSDs, 3) K-S test of CSDs to normal, lognormal, and gamma distributions, and 4) t-test of the gamma distribution shape factor, alpha. Dolomite CSDs are more closely represented by the gamma distribution than the normal or lognormal distributions. Trenton CSDs are not significantly different from each other despite significant differences in mean grain size. The pattern of CSD shape does not change relative to mean grain size. Saluda CSDs are not different from each other, but are different from Trenton CSDs. Theoretical models do not resemble the dolomite CSDs. Acknowledgements Many thanks go the the MSU Geology Department Faculty and Staff, for their assistance, encouragement, and financial support. I appreciate the opportunity to study under the guidance of Duncan F. Sibley, Michael A. Velbel, and David T. Long. I appreciate being able to meet and talk with Aureal T. Cross, John T. Wilband, Thomas A. Vogel, Grahm Larson, F.W. Cambray, Hugh Bennett, and Bob Anstey. My thanks goes to Jill and Tom Stebbins for welcoming me into their busy and wonder- ful household in Okemos. I would like to acknowledge my friends (whose advice to fin- ish as soon as possible was promptly ignored, yet they remain good friends) Myung Yi, Abdule Muhanna, Mohammad Ghavidal-Syooki, Mounir Saad, and 800 Meen Wee. Acknowledgement should also go to Sgt. McCloud (Dave Cook) and his sidekick crony in crime, Chester (Erin Lynch) for welcoming me to MSU. I want to thank my family for their humor throughout this ordeal. iii TABLE OF CONTENTS LIST OF TABLES ................................................................................................... vi LIST OF FIGURES ................................................................................................. viii INTRODUCTION .................................................................................................. 1 GENERAL GEOLOGIC SETTINGS OF SAMPLE DOLOMITES ..................... 3 Trenton Formation Dolomite ............................................................................. 3 Saluda Formation Dolomite ............................................................................... 7 COMPUTER - GENERATED MICROSTRUCTU RES AND ANALYSES ........ 12 METHODS ........................................ . ..................................................................... 18 Method of Crystal Size Distribution Measurement ............................................ 18 Stereology of CSD Determination ...................................................................... 18 Statistical Analyses ............................................................................................. 24 Method Reproducibility ...................................................................................... 32 CSD DATA ............................................................................................................. 43 Trenton Formation ............................................................................................... 43 Saluda Formation ................................................................................................ 50 Theoretical Computer - Generated Microstructures ........................................... 5 3 Analysis and Comparison Between Formation and Theoretical CSDs .............. 55 DISCUSSION ......................................................................................................... 58 CONCLUSIONS ..................................................................................................... 63 APPENDD( A Thin-Section Description, Photographs And Drawing ........................................ 65 APPENDD( B Two-Sample Kolmogorov—Smimov Goodness-Of-Fit Tests ............................... 82 iv TABLE OF CONTENTS (cont’d) APPENDIX C Normalized Crystal Size Distribution Frequency Histograms And Crystal Size Distribution To Thin-Section Sample Key ...................................... 88 BIBLIOGRAPHY ................................................................................................... 127 10 ll 12 l3 14 LIST OF TABLES EAQE Two-Sample Kolmogorov-Smirnov Test Evidence of Reproducibility On Measured Crystal Size Distribution Data ................ 41 Comparison of Statistical Values of Duplicate CSD Counts and Thin-Section Samples ....................................................................... 42 Trenton Formation CSD Statistical Values ....................................... 44-45 Two Sample K-S Tests Between Thin-Section TLl Clasts .................... 47 Two Sample K-S Tests Between Thin-Section TL2 Clasts .................... 47 Two Sample K-S Tests Between Thin-Section TL3 Clasts .................... 48 Two Sample K-S Tests Between Thin-Section TL7 Clasts .................... 48 Two Sample K—S Tests Between Thin-Section TL8 Clasts .................... 49 Two Sample K-S Tests Between Thin-Section TL9 Clasts .................... 49 Two Sample K-S Tests Between Thin-Section TLll Clasts ................... 49 Saluda Formation CSD Statistical Values ............................................... 52 Two-Sample Kolmogorov-Smimov Goodness-Of-Fit Tests Between Saluda Formation Samples ..................................................................... 53 Theoretical Computer-Generated Microstmcture CSD Statistical Values .......... 54 Two-Sample Kolmogorov-Smirnov Goodness-Of-Fit Tests Between Normalized Theoretical Computer-Generated Microstructure CSDs ..... 55 vi 15 LIST OF TABLES (cont’d) Comparison of Mean and Standard Deviations of the Means and Standard Deviations of the Alpha, Normalized StandardDeviation, Skewness, and Inclusive Graphic Skewness Values for the Saluda and Trenton Formations .......................................................................... 56 vii FIGURE LIST OF FIGURES Regional sample location map of theTrenton Formation (middle Ordovician) core samples within the Michigan Basin and the Saluda Formation (upper Ordovician) outcrop samples on the western flank of the Cincinnati Arch. .................................................. Detail map of the Trenton Formation core sample location with the well lease names listed. The wells from which core samples were investigated in this study are circled (after Miller, 1988). ................... Photomicrograph of Trenton Formation limestone conglomerate showing rounded quartz grain matrix .................................................. Detail map of the Saluda Formation (upper Ordovician) outcrop sample location (after Walters, 1988). ................................................. General stratigraphy of the Cincinnatian Series as determined by various authors (from Davis, 1986). .................................................... Computer generated microstructures (from Fridy et al. 1992) with corresponding CSD frequency histograms. Nucleation and growth models are a) Johnson-Mehl, b) Site-Saturation (cellular), and c) Site- Saturation with weakly clustered nuclei. ................................ Size histogram of circles measured from intersections on several sphere sizes is the sum of the individual disu'ibutions shown by the differently shaded bars (after Russ, 1986). ......................................... CSD frequency histograms of Boi Doi dolomite from Aruba, Netherlands Antilles. Histograms are from a) thin-section, and b) disaggregated grain-mount. ............................................................. viii ..... 4 ..... 6 ..... 7 ..... 8 ..... 9 ..... l3 ..... 20 ..... 21 FIGURE 10 11 12 13 14 15 16 LIST OF FIGURES (cont’d) a) Shaded grains show those measured in a line point count, and b) the corresponding CSD frequency histogram. ............................ Densities of the gamma and lognormal distributions with parameters selected to give the maximum value .54 at x=1 (after Breiman, 1973). .................................................................... a) frequency histograms, and b) cumulative relative frequency distributions of Gamma distributions using a constant [3 (scale) value and different or (shape) values. ............................................. a) frequency histograms, and b) cumulative relative frequency distributions of Gamma distributions using a constant or (shape) value and different B (scale) values. ............................................... a) frequency histograms, and b) cumulative relative frequency distributions of Gamma distributions using equal or (shape) and B (scale) values. ................................................................................. Two of the three frequency histograms of line point counts of Trenton clast TLlA. (Note: size data is measured data and not normalized.) .................................................................................... Respective cumulative relative frequency distributions of the frequency histograms of Trenton clast TLlA shown in Figure 14. Two of the three frequency histograms of line point counts of Trenton clast TLlB. The solid line is a fitted gamma distribution. (Note: size data is measured data and not normalized.) ................. ......... 23 .......... 28 .......... 29 .......... 30 .......... 31 .......... 33 ......... 34 .......... 35 FIGURE 17 18 19 20 21 22 23 LIST OF FIGURES (cont’d) Respective cumulative relative frequency distributions of frequency histograms of Trenton clast TLlB shown in Figure 16. .................... Frequency histograms of duplicate line point counts of Boi Doi dolomite from Aruba, Netherlands Antilles. The solid line is a fitted gamma distribution. (Note: size data is measured data and not normalized.) ................................................................................ Respective cumulative relative frequency distributions of the frequency histograms of the Boi Doi dolomite shown in Figure 18. Frequency histograms of line point counts of duplicate thin-section samples of the same clast from the Trenton Formation. (Note: size data is measured data and not normalized.) ...................................... Respective cumulative relative frequency distributions of the frequency histograms shown in Figure 20. ....................................... Two of the eight frequency histograms of the Saluda dolomite samples. ............................................................................................. Kolmogorov-Smirnov goodness-of-fit test cumulative relative frequency distribution showing the consistent differences between the Saluda and Trenton Formation CSDs. .......................... EAGE ....... 36 ....... 37 ....... 38 ....... 39 ....... 4O ....... 51 ....... 58 INTRODUCTION The crystal size distribution (CSD) of a single phase, polycrystalline solid will vary according to the nucleation and crystal growth behavior during the transformation, or recrystallization, of that solid. Friedman (1965) recognized the importance of CSDs in describing the character of carbonate rocks such as dolomite, by classifying those with a relatively uniform CSD as equigranular and those with a polymodal CSD as inequigranular. Sibley and Gregg (1987) suggested that unimodal (equigranular) dis- tributions result from a single nucleation event in a homogeneous substrate, and that polymodal (inequigranular) distributions result from nucleation in an inhomogeneous substrate, or multiple nucleation events. Marsh (1988) used CSDs to study the kinet- ics of crystallization in metamorphic and plutonic rocks. Marsh’s basis for using CSD data was that it yields quantitative kinetic data that can be applied to understanding geochemical systems independent of the development of exact kinetic theory for the system under consideration (Marsh, 1988, p.278). Many experimental CSDs have been observed, particularly in the material science field, often showing coarsely skewed, lognormal shapes to the distributions. This fact, and the effect of nucleation and crystal growth behavior on the crystal size dis- tribution, has been investigated using a number of computer models in which vary- ing nucleation and crystal growth processes can be chosen to generate a polycrystalline solid (Mahin, Hanson, and Morris, 1976, 1980; Saetre, Hunderi, and Nes, 1986; Marthinsen et al., 1989). A range of computer generated CSDs with specific crystal ' 2 nucleation and growth processes can be compared to experimentally derived CSDs to assess the nucleation and growth characteristics of these systems. In this study, three computer-generated CSDs are used to evaluate experimental size distributions measured in dolomites. Dolomite from the Trenton Formation, Middle Ordovician, of Michigan, and the Saluda Formation, Cincinnatian Series, Upper Ordovician, of Indiana were inves- tigated in this study. Rocks from these formations were chosen because of the different mean grain sizes within the formations and different temperatures of dolomitization between the formations. The major limit of CSD data is that there is more than one way (nucleation and growth kinetics) of generating a given size distribution. For example, a transformation with an increasing nucleation rate and a constant growth rate may have a similar CSD to one with a constant nucleation rate and decreasing growth rate. Alternatively, differing CSD characteristics will result if a constant growth rate is maintained and the nucleation rate is varied. This is illustrated by several computer generated CSDs (Saetre et al., 1986; Marthinsen et al., 1989; Frost & Thompson, 1987). Similarly, Larikov (1986) generated nearly identical percent transformation sigmoidal graphs using a constant growth rate, but using different nucleation frequencies. The purpose of this study is to compare the shape of CSDs from within a given popula- tion (formation), between populations (formations), and to theoretical CSDs, to place constraints on the interpretation of CSDs, thereby illuminating the influences of the dif- fering conditions under which dolomites form. GENERAL GEOLOGIC SETTINGS OF SAMPLE DOLOMITES Samples from two locations were investigated for this study. The first sample location is the epigenetic, fracture-related dolomite from the Trenton Formation, Middle Ordovician, within the Michigan Basin. The Trenton Formation samples are cored inter- vals from wells located in Jackson County, Michigan. Figure 1 shows the sample loca- tion in reference to the Michigan Basin. The second sample location is the Saluda Formation, Upper Ordovician, located in Jefferson County of southeastern Indiana. Figure 1 shows the Saluda Formation sample location in reference to the Cincinnati Arch and Illinois Basin. Trenton Formation Dolomite The Trenton Formation overlies the St. Peter Sandstone (Lower Ordovician) and generally grades into the overlying Utica Shale (Upper Ordovician). The thickness of the Trenton Formation ranges from about 50 meters in the northeast to about 150 meters in the southeast of Michigan. The southeastward thickening of the formation probably rep- resents carbonate platform development in that area. The top of the Trenton appears to be a regionally extensive hardground (Keith, 1985). The Trenton Formation is approxi- mately 110 meters thick in the study sample location of Jackson County, Michigan. The Trenton Formation in this location is probably deposited in a deep subtidal environment (Wilson and Sungepta, 1985). Three types of dolomites have been recognized in the Trenton Formation of the Michigan THENTON FORMATION CORE SAMPLE LOCATION Permian lllllll L'" "Min. IIII Pennsylvanian Devonian Ordovician mi W SALUDA FORMATION OUTCROP SAMPLE LOCATION figure I Regional sample location map of the Trenton Formation (middle Ordovician) core samples within the Michigan Basin and the Saluda Formation (upper Ordovician) outcrop samples on the western flank of the Cincinnati Arch. 5 Basin (Taylor and Sibley, 1986). A ‘cap’ dolomite exists at the upper few meters of the Trenton that is in contact with the Utica Shale and is distinctly ferroan (approximately 7 mole % FeCO3). A ‘fracture-related’ dolomite exists which is related to subsurface fractures, and structures of the basin. It is characterized by linear trends of epigenetic dolomites such as that found along the northwest-trending Albion-Scipio Trend which transects southeastern Jackson County, Michigan. A ‘regional’ dolomite is confined to the southwestern and western edges of the basin and does not extend into the study area. The Trenton core samples used in this study are considered to be part of the fracture- related dolomites taken from Jackson County, Michigan (depths of approximately 4850 to 4930 feet below sea level). Most of the formation in the study area is limestone, but the cored intervals for this study contain partially and completely dolomitized strata. Figure 2 is a local area map showing the well locations (from Miller, 1988). Much of the Trenton Formation in the study area consists of a mudstone or wackestone clast limestone. The dolomite is slightly calcium rich having a mean of 51 mole % Ca [based on position of d(104)], (Miller, 1988). Taylor and Sibley (1986) calculated a temperature of precipitation of approximately 80°C by using oxygen isotope data. The samples from these locations and depths were chosen for study because they are dolomitized intraclastic limestones which show significant textural variations between the clasts of the conglomerate. The textural variations of clasts in close proximity elimi- nates differences in overall solution chemistry or temperature as a control on the result- ing dolomite textures. The clasts range in size from a few millimeters to several centimeters in diameter. The clasts are generally surrounded by a matrix of carbonate mud and quartz silt. The silt is not found within the clasts, or within cemented fractures of some clasts, which shows the rocks to be true conglomerates, not collapse breccias. Dolomitization followed the lithifr- cation and subsequent deposition of the conglomerate as evidenced by the fact that the A32 .552 .33 0288 v.8 beam £5 E 839395 203 BEES 28 523 Sec «:03 2F .33.: 3.5: 9.8. :03 05 .23 5:82 0389. 28 392.com :95; 05 .8 9:: =83 N 8:9...— hT- ocmxz<: A a a e 2 V O- 32.52: mmmoo zepzmmh o a... N— 593.... _ a... Tu . . A.“ V63 5:: p 2... . 3 z W— ._. 5.3:. 5:: \ .92.. .0258 5.3.: . m h .0 2. 03 2 p a . 2.22... 36.: E :03 \ a?“ .83 o. 5.3:. 52“. W 19. 9: x03 .. z 2 <1 7363 o : ZOSZ<2 P N m m w . . .ll.. . . w . 2 ME >> Figure 3 Photomicrograph of Trenton Formation limestone conglomerate showing rounded quartz grain matrix. Photographs of the thin-section, and drawings outlining and labeling the clasts are shown in Appendix A. A brief description of each clast studied in this investigation is also given in Appendix A. Saluda Formation Dolomite The Saluda Formation samples analyzed in this study were obtained from a road cut along Highway 421, in Jefferson County of southeastern Indiana, approximately 3 miles north of Madison, Indiana, near the Kentucky-Indiana border. Figure 4 is a detail sample location map showing the location of the road cut. This site is located on the western flank of the Cincinnati dome/arch, toward the Illinois basin. The Saluda Formation is Upper Ordovician and part of the Richmond Group of the Cincinnatian Series. _._.._. _.RIOHMONOa] IT I : WAYNE ' ' l.._..1 “““ 'I I I nusu | : . PREBLE : i I UNON I INDIANA I I FAYETTE : .._.. ...._-_.. —-i i i__..—---—.-.—| OHIO l- "—' I FRANKLIN I BUTLER I ' HAMBURG l = ¢' In = ° . I I DECATUR ) H: U Q” . H i ' I ' /--I/ may : cmcmmn —‘ IDEARBORN = VERSAWLLES ' \-"’ . l . , \ , \.‘\@ \ . i JENNINGS-1.. .._I!” ~ —1"_1.l.._.,_ ._.r‘ ! '4’ErFFERSON .. I !SWITZERLANQ <\ ‘ . I" ' 'uverrson .._. I ,1 @5/ i SCOTT ' \. \./ CARR/OLL w . I TRIMBLE ' ./ """""-'-\ agorono’ iIn--=i ' “m /,5.é/ " ‘ KENTUCKY I I-“@ {SKY IGHT I I N VEDW‘” ' 20 munfl I)‘ LOUISVILLE JEFFERSON fir SAMPLE OUTCROP LOCATION Figure 4 Detail map of the Saluda Formation (upper Ordovician) outcrop sample location (after Walters, 1988). 9 dolomite in the partially dolomitized samples tends to form around the edges of the clasts. Figure 3 is a photomicrograph showing the edge of a clast and the rounded quartz in the matrix. Figure 5 shows the general stratigraphy of the Cincinnatian Series as determined by vari- ous authors (from Davis, 1986). Following the work of Walters (1988), the Saluda lies above the Liberty Formation and generally lies below, but interfingers with the Whitewater Formation above it. The Saluda thickens to the south and the Whitewater thickens to the north. The thickness of the Saluda is approximately 60 feet in the study area (Brown & Lineback, 1966). us us Mum SI 0000.“ '40.. cor-011.500 sumo: swowo untrue-Iv 3.1m It“ cc»:- on... a in uremic" «ma. III. 3 l nun-m in... u .4. ma. then. tout tam. mt a ea a hoe. ma non mm mm a 5-0.. mm an. and. run but It". vim tau (um mates . Wltfl'“ mi mu minute- a 3"!“ a, ‘ Wit-LL: ... . ‘ WH'EMTgl ,I Hull 0' 2'! '- mum I mum man In. ....... ‘ - p \ 5 H 253‘ “W” uwoa mum \\ 5 mount I m. \ 'i 2 . Luann wit 5 g ’3‘; um“ <"‘" '0" ‘ 'U 2 5 ,3. “M"“u' mu noun MI E E -‘ cLAmvut ”I. - '0" i K i “nature“ m H mm 3 c U ————I a 3 3 cum 1 ___r m i . awn annual " I I - ml. 2 .1. “W I 3' L8 W ”W g I: am! i g 3; comm“: ma. cm'WI-u o 3 wt: ‘2’ 5' “new! W ““‘W‘ ““‘w‘ u 0 g ammo”; mum M m. . g It you L/ "awn! 2 :1: mu m * M sour—care “’9‘ u 3 2 ‘0" ,u on KO“ m In I! -' (comm W FIGURE 5 General stratigraphy of the Cincinnatian Series as determined by various authors .(from Davis, 1986). The Saluda is predominantly dolomite. Brown and Lineback (1966) indiCate a distinc- tive contact at the base of the Saluda with the underlying strata. However, other authors describe the base of the Saluda to be gradational with the underlying strata, which is the 10 case at the sample location for this work. A distinctive zone of colonial corals exists near the base of the Saluda. The Saluda is predominantly overlain by, and grades into, the Whitewater Formation, which also contains a variety of limestone types interbedded with calcareous shales. In much of Jefferson County and Clark County to the south, the Saluda is disconforrnably overlain by the Silurian Brassfield Limestone (Brown & Lineback, 1966). Post-Ordovician erosion removed the uppermost Ordovician and low- ermost Silurian strata, and in places the Saluda and Whitewater formations are overlain by upper lower Silurian strata (Walters, 1988 ref. of Hattin, 1961) . At Madison, Indiana the Saluda consists of a section of thinly to thickly-bedded, biotur- bated, dolomitized mudstones and wackestones, that is interbedded with lime grainstone lenses and overlain by approximately 15 meters of laminated, dolomitized mudstone. All the samples obtained for this study are mudstones from interbedded grainstones and mudstones. Overlying the interbedded grainstones and mudstones are laminated, dolomitized mud- stones which contain occasional mudcracks and rip-up clasts, but show no evidence of evaporite deposition. The laminated, mudstone section is completely dolomitized, as is the upper bioturbated mudstone portion of the mudstone-grainstone facies. The dolomite contains 44-48 mole % Mg [based on position of d(104)]. The amount of dolomite in the mudstone decreases down section, however, and partially dolomitized bioturbated mud- stones are found approximately 10 meters below the base of the laminated mudstone facies. Mudstones with 50% dolomite occur as much as 20 meters below the base of the laminated mudstone facies. The grainstone lenses contain fragments of brachiopods, bryozoans, trilobites, and crinoids. The wackestones contain fragments of bryozoans and brachiopods. The ll grainstone lenses are also limestones or partially dolomitized, and the dolomite is gener- ally confined to the mud found within the sheltered pores of the grainstone. The grain- stone lenses are approximately 5 to 30 cm thick. They appear to be storm-washed deposits, as indicated by typically undulating bases with stacked and concave down bra- chiopods, overlain by crinoidal and bryozoan fragments, and terminate with relatively flat tops. The grainstones often pinch out laterally within a few meters. Deeper in the section, the grainstones are thinner and laterally more continuous. The dolomite is unimodal planar and either does not replace allochems, or replaces them non-mimetically. Dolomite cement partially fills fossil molds (formerly aragonite), the remainder of which is filled with coarse, equant, orange cathodoluminescent (CL) calcite spar. The dolomite crystals have thin CL zones, and often have corroded interiors. The CL zones can be correlated through the upper 20 meters of the section, including the grainstone-mudstone facies. The zones in the dolomite deeper in the section are too faint to correlate, but those in the upper section indicate that the dolomitizing solutions were the same for the grainstones as for the mudstones. The facies control on dolomite distribution in the Saluda is consistent with early diage- netic dolomitization. Hatfield (1965) suggested brines. Regardless of the water chem- istry, the lack of deep burial in the area (Beaumont et al., 1988) is consistent with dolomitization at low temperatures. COMPUTER - GENERATED MICROSTRUCTURES AND ANALYSES Mahin, Hanson and Morris (1976), developed a computer model to construct single- phase, polycrystalline microstructures for the purpose of characterizing the generation of grain shape. The model is sufficiently general to treat any nucleation and growth process in a one-phase solid. Because most crystal size distribution analyses are conducted in two dimensions, a planar section from the computer-generated microstructure unit cube was also generated. Two nucleation and growth models were used to illustrate the technique (Figure 6). The site saturation model, also referred to as the cellular model, begins with randomly-distributed nucleation sites in an isotropic, one-phase solid, which all nucleate simultaneously and grow uniformly as equi-sized spheres until impingement. Following impingement, the grains have planar boundaries to each other and grow according to the free space available. In the Johnson-Mehl model, nuclei are randomly distributed, form at a constant rate within the unit cube, and grow uniformly until impingement. The nucleation sites and times are random. This results in the unit cube being filled with grains of varying sizes and ages throughout the transformation, and in grain boundaries which are hyperboloids of revolution. In both models the growth rate is constant. A third microstructure, included in Figure 6, is a site saturation model with the nucleation sites being weakly clustered. The corresponding CSD frequency histograms are also presented with each microstructure in Figure 6. These microstructure prints are provided by Dr. Knut Marthinsen, Department of Physics and Mathematics, Norwegian Institute of Technology, Trondheim, Norway, (Fridy, Marthinsen, Rouns, Lippert, Nes, and Richmond, 1992). 12 ‘ In «a s- ' t 4 I. ‘*" ‘.hv‘b f r mama ’ I 393%“ L ‘C $1 I D 3% (0 '34"! b i v! 5.. 9:: {9? is; Q" é‘ 0: B:- 13: O .5 5 'Iiméfizgflfi €‘ .wflhw 'v“ . 5 ‘A .521.» ~ g" I'm ”Autogr- — I l u . fifi—r v I e- .. F 1 4 uv- _ a u- _ ’ . r . I‘ .4 l‘ . . ... _ 1 4 ., n . l . A .u h. n. . n J frcquuncg KHJNSMEL.NormSiZI e '>— 7 0' l 75 a I J “9 I i I ..- i l .2 xc : l i l . l—I—‘frh I [—1 I: 3. Ob \ E a, .0. n‘ 1 a frcquuncu Q h 3 9 s3 v ,5. It .‘ 61%. at .'""hn a ‘ia: A EV. '5 .1" . : ’V I ..l l-' I-l l «:- u w w ... w KHSITSAT.Nor-m$izc 1.7 v ‘Ofl‘t'li‘ mgaJtém ' fruquuncu -e.n m 0.0 ... e.- KHSSUKCLoNormSiZI C) Computer generated microstructures (from Fridy et al. 1992) with corresponding CSD frequency histograms. Nucleation and growth models are a) lohnson-Mehl, b) Site-Saturation (cellular), and c) Site- Saturation with weakly clustered nuclei. 14 The goal of Mahin, Hanson and Morris (1976) was to relate the topological features of well-defined microstructures to the nucleation and growth laws which generated them. “Physical experiments are limited by reproducibility, and the lack of total environmental control. The theoretical analysis, based on known statistical theorems, provides the abili- ty to reproduce the sections and transformation control, but is limited by the scarcity of well defined models and theorems. Valid computer simulation, on the other hand, is able to extend the attributes of the theoretical work to include highly detailed two-dimension- al representations of the progression of a transformation in time and space, as well as detailed three-dimensional information for any time or space.” (Mahin, Hanson and Morris, 1976, page 39-40). For example, serial sections through microstructures of theo- retical nucleation and growth models are useful aspects of computer-generated microstructures for crystal size and shape analyses. Mahin, Hansen and Morris (1976) concluded that it is possible to demonstrate theoretically that microstructures of a given model type (site saturation, Johnson-Mehl, etc.) will be geometrically equivalent, regard- less of the nucleation/growth ratio (Nv/G). They generated nearly identical, logarithmic-like, CSD frequency histograms for two Johnson-Mehl model microstructures. One of the Johnson-Mehl microstructures had a nucleation-to-growth ratio of 40 grains per unit volume, and the other had 244 grains per unit volume. Although the mean grain size changed, the shape of the CSDs remained the same. They concluded that the results followed the theoretical predictions in all cases, indicating that the simulation is valid at least for simple processes. Mahin, Hanson and Morris (1980) investigated the nature of the distributions of quanti- ties such as the number of sides, grain areas, and intercept lengths of a line transecting the grains on a planar section of site saturation, and Johnson-Mehl model microstructures. The frequency distributions of normalized grain areas and grain diame- ters did reveal qualitative differences between the site saturation and Johnson-Mehl 15 microstructures. The distribution of intercept lengths did not show as distinct a difference in the frequency histograms of the CSDs of the two microstructures. Saetre, Hunderi and Nes (1986), constructed microstructures from the site saturation and Johnson-Mehl nucleation and growth models as well, and studied three additional mod- els. A third model consisted of a decreasing nucleation rate accompanied by a constant growth rate. A fourth model incorporated an increasing nucleation rate with a constant growth rate, and a fifth model was composed of a constant nucleation rate and a decreas- ing growth rate. By holding the growth rate the same in the first four models, the effect of nucleation frequency on crystal size distribution can be seen. The models with an increasing nucleation rate or a decreasing growth rate were quite similar, and were the ones resulting in the most lognormal-like distributions. An increasing nucleation frequency, and consequently the relative nucleation rate, results in a more coarsely skewed CSD than the site saturation model because younger, smaller grains will develop before all available space is consumed by the growth of the older grains. Generally, as the nucleation frequency increases, the nucleation density increas- es, and greater number of younger, smaller grains will be allowed to form in the uncon- sumed space of the unit cube. The resulting grain size distribution will contain a smaller mean grain size, a smaller mode, and a more coarsely-skewed distribution than a Johnson-Mehl model with the same growth rate. By holding nucleation frequency con- stant, the effect of varying growth rates may be viewed. An increasing growth rate, rela- tive to a constant growth rate, would shorten the completion time of the transformation, and decrease the time and space available for new nucleation sites to form throughout the transformation. The space will be consumed at a relatively faster pace by. the growing grains, thereby decreasing the number of subsequent nucleation events which can take place during the transformation. The resulting CSD would show a slightly less 16 coarsely-skewed distribution than a transformation with the same nucleation frequency and a constant growth rate. The opposite would be true for a corresponding decreasing growth rate. It would seem unlikely that nucleation would continue at a constant rate/fre- quency if the growth of existing grains is decreasing, unless the growth rates were some— how a surface-reaction-controlled process. Saetre, Hunderi & Nes (1986) produce several CSD histograms from the models described above which show that an increase in the nucleation rate serves to increase the number and peak frequency of small grains. This will lower the mean crystal size, and, generally, increase the size to mean-size ratio. This subsequently spreads out the distribution of the interrnediately-sized grains, and produces a more lognormal-like normalized CSD. Marthinsen, Lohne and Nes (1989) produced similar frequency histograms for both par- tially- and fully-recrystallized microstructures in both the site saturation and Johnson- Mehl models. The partially-recrystallized structures were investigated because the other simulated microstructures did not allow for any grain competition or grain growth after impingement, which would happen in real structures. The comparison of partially- and fully-recrystallized microstructures shows that the shape of the distribution remains essentially the same, and that the effect of impingement serves only to lower the peak frequency and consequently broaden the distribution. However, the effect of impingement appeared to show a greater influence on the site-saturation model CSD than on the Johnson-Mehl model CSD. Marthinsen, Lohne and Nes (1989) also introduced non-uniformity with respect to the distribution of recrystallization nuclei and to the growth of new grains. This was done because experiments have shown that the recrystallization process is exceedingly inho- mogeneous. Two methods of introducing non-uniformity were used in their study. The first method introduced non-uniformity by dividing a lohnson-Mehl model unit cube into 17 two areas, with one area having a much higher nucleation density than the other. The other method divided the recrystallized nuclei into classes, each of which was associated with a different decreasing growth rate. This second method was simulated using site saturation (instantaneous nucleation), Johnson-Mehl (constant nucleation), and increas- ing nucleation rates. The nuclei were distributed among the classes lognormally, in that the highest growth rate was assigned to the class with the fewest nuclei. The model of classes with different decreasing growth rates is based on a model for particle-stimulated nucleation of recrystallization in which it is assumed that the nucleation of recrystalliza- tion is restricted to the deformation zones surrounding large particles. The deformation zones and the amount of stored deformational energy is proportional to the particle size. The stored def ormational energy is the driving force for the growth of the recrystallized grain. It is largest at the particle, and decreases throughout the deformation zone. Thus, the initial growth rate is largest at the largest particles. The modeling of lognormally dis- tributed nuclei growth rates is based on the lognormal grain size distribution often observed in commercial alloys. The relevant aspect of the simulations to this study is the modeling of many different growth rates for many grains within the same microstructure, such as in flux-limited growth. The effect of altering the nucleation rates by creating the two zones with different nucleation densities did not significantly change the resulting CSD from that of a straight Johnson-Mehl nucleation and growth model. For the models with the introduction of classes of grains with different decreasing growth rates, none of the CSDs closely simulated the lognormal CSD. The CSDs with site saturation and Johnson-Mehl nucleation kinetics were broader, and subsequently had slightly lower peak frequencies, than their counterparts with isotropic, constant growth rates. The model with increasing nucleation rate was most similar to the lognormal distribution, and compared favorably to the increasing nucleation rate and decreasing growth rate models developed by Saetre, Hunderi & Nes. Again, it seems unlikely that an increasing nucle- ation rate would occur with a constant growth rate, or in this case classes with different decreasing growth rates, without a surface-reaction-controlling factor. METHODS Method of Crystal Size Distribution Measurement In this study the CSDs of the thin-sections from the Trenton and Saluda were determined by taking line point count measurements. The line point counting method is conducted by traversing across a thin-section (or dolomite clast in the case of the Trenton) in which all of the crystals which touch the cross-hairs of the ocular along that traverse are includ- ed in the count. The longest diameter of each crystal encountered during the traverse of the thin section is measured and recorded. The grains on the edges of the clast or thin section were not measured to eliminate boundary effects. At the end of the traverse, the thin-section or clast is off-set approximately 1.5 to 2 times the size of the larger-sized grains measured in the first traverse, and a second traverse is begun. Those grains large enough to cross two traverses were counted only once. The number of grains measured per sample ranged from 199 to 300. The purpose of the line point counting method of CSD measurement described above is to minimize the bias toward the larger grains, in comparison to the normal point counting method. The method does not completely elim- inate the large grain bias. Stereology of CSD Determination The two-dimensional view of a microstructure obtained by slicing a planar section through the unit cube will show a different size distribution than would be observed for the true grain diameters viewed in 3-dimension. The resulting distribution is generally 18 l9 coarsely-skewed; that is, fewer large grains are observed. This occurs because the proba- bility of obtaining a longest-axis cross section of all crystals encountered by a planar cut through the polycrystalline unit cube is low compared to obtaining some smallerportion of the crystals within the planar section, or thin section (Lorenz, 1989; Russ, 1986). This fact was illustrated by Krumbein (1935) in his size distribution comparison between a thin section and disaggregated grains of the St. Peter sandstone. There is, however, no accurate way to theoretically determine the relationship between true and apparent sizes for irregular objects of unknown size distribution. The probability of obtaining a particular circle diameter is related to the vertical thickness of a slice of the sphere with that size (Russ, 1986). Cashman and Marsh (1988) showed that the CSD, or density distribution curve for the apparent size of uniformly- sized spheres in thin section, could be calculated. The attempt to determine or calculate the true sizes and distributions becomes problematic when dealing with spheres of differ- ent sizes. The apparent size distribution is affected not only by the probability that the apparent diameter of any one sphere will be smaller than its true diameter due to the effect of sectioning, but also because there exists a greater chance of intersecting a large sphere than a small one (Cashman and Marsh, 1988). Russ (1986) gave an example where the smaller grain sizes observed in thin section may be contributed to from the smaller portions of larger grains as well as grains with that true diameter. The frequency distribution of each size will add, giving rise to a complex histogram such as that shown in Figure 7. 20 Frequency 40 Section Diameter (urn) FIGURE 7 Size histogram of circles measured from intersections on several sphere sizes is the sum of the individual distributions shown by the differently shaded bars (after Russ, 1986). The problem of true and apparent grain sizes was investigated in this study by conduct- ing an empirical check of size distributions of dolomite in both two and three dimensions. A CSD was determined on a friable dolomite sample from Aruba, Netherlands Antilles (BD6TS). A second CSD was determined from a grain mount of disaggregated grains from the same sample (BD6GM). The diameters measured in the grain mounts are true diameters. Figure 8 shows the frequency histograms and cumula- tive frequency distribution curves of the CSD’s resulting from the grain mount and thin section line point counts. As in the St. Peter sandstone example conducted by Krumbein, the histograms and cumulative frequency distribution curves show that the CSDs between the two and three dimension have changed, and not merely shifted. However, these graphs indicate that the bias due to thin sectioning of dolomites is generally minor because the dolomite crystals tend to maintain an equant form. In the line point count, it is apparent that a line placed randomly across a polycrystalline microstructure may intersect more of the larger grains than the smaller ones, resulting in 21 Frcqucncg Histogram 1 .1 4 fl 4 :4 d J .1 .4 UNITS I 1 x 10' um frequencg 8 I I I I I I I 7 I I I I I I T l T I I I ' A l .. . #J h Irrrrlrrrrlaarrlrrrr '1 ’_J UNITS - 1 x 10' um 3. .... I l l A A A I .l A A A l j J I A l A L I A fr-quancg I I I I I l I 'I I I I I I I I I I I I I I l l J l J I l l l l I l l l l l l l I I l l A l l i r- )- i P BD$GM.sizc figure 8 CSD frequency histograms of Boi Doi dolomite from Aruba, Netherlands Antilles. Histograms are from a) thin-section, and b) disaggregated grain- tmmm. 22 the distribution being slightly more finely skewed than a CSD including all grains. Figure 9 shows the microstructure of a site saturation model on which the grains measured in the line point count have been shaded. It is apparent that more of the small- er-grained areas are excluded from the line point count than if all of the grains were mea- sured. However, it is also apparent that more of the smaller grains are included than if a grid-based point count were completed. For the purposes of this study it is assumed that if the same method of measuring grain sizes and determining CSDs is applied to all experimental samples and computer-generated models, the resulting CSDs will represent the nucleation and growth processes of the sample. The problem of the difference in the true and apparent CSDs is diminished in this study because both the experimental and theoretical CSDs are determined using the same method of measurement from a two- dimensional view of the microstructures. Saetre, Hunderi and Nes (1986) point out the problem of the smaller grains being lost in experimental CSD analyses because of either the sample preparation procedures, or the limiting resolving power of the technique used to image, identify, and measure the grains. They propose using a cut-off effect in the computer-generated microstructures, to eliminate small grains in order to simulate the experimental effect in the computer mod- els. They removed all grains smaller than 0.153 of the mean grain area. The cut-off effect is not very noticeable on the linear or logarithmic scale frequency histograms. It is quite noticeable, however, when it is plotted as a cumulative frequency distribution. This cut-off gives the tendency towards a more lognormal distribution for the Johnson-Mehl model. They note that when comparing experimental distributions to theoretical ones, the cut-off effect is relatively unimportant when comparing probability densities, but is substantial when comparing cumulative distributions, noting that cumulative distributions are more sensitive to variations at the small areas. It might be noted that the line point count method for the experimental CSDs may slightly exaggerate this cut-off frequency Figure9 y~ 1 «'11:, lglfigéNg gall: s' . to .3/9‘gQ‘é‘fi’g’iv'fi‘i-‘Wc‘; , , l. a) ’73.). , , \I'L‘Zh “‘3?" ‘1': il|nf§ _-"®a£\mpb’s~>3-Y:O;‘i IVA“ |—' fr fi r I ' ' a. _ F— i. [—1 KMSITSQT.sizc a) Shaded grains show those measured in a line point count, and b) the corresponding CSD frequency histogram. 24 effect by eliminating a greater number of the small grains from the count and tending to produce a more normal-like distribution. However, the line point count would most like- ly simulate this cut-off effect in the computer-generated models. The cut-off effect was applied to the experimental CSDs as well as to the computer-generated microstructure CSDs, and it was found that it made very little difference in the resulting cumulative fre- quency distribution curves. For this reason a cut-off effect was not applied to the com- puter-generated model CSDs when comparing them to the empirical CSDs. Statistical Analyses Five statistical methods of comparing the CSDs were applied to this study, to character- ize the differences in shape of the CSDs. Two of the statistical methods rely on the Kolmogorov-Smirnov goodness-of-fit test As indicated above, comparing the cumula— tive distributions is a more sensitive measurement of the variations in small areas than that of the frequency histograms. The Kolmogorov-Smimov test is a nonparametric sta- tistical procedure which measures the difference between two cumulative distribution functions. The test was originally developed for continuous distributions. However, it can be applied to discrete distributions as well, though the critical values tend to be over- conservative with discrete distributions [i.e. the true may be less than the nominal a (Neave and Worthington, 1988, p.90)]. The Kolmogorov-Smirnov test determines the differences between two distributions by measuring the maximum vertical distance (Maximum D) between each cumulative distribution function at any point in the two dis- tributions. Using the STATGRAPHICS Statistical Program, version 4.2, the two distrib- utions may be a theoretical distribution compared to an experimental distribution (one-sample test) or two experimental distributions (two-sample test). The number of n values do not have to be the same in each distribution to perform the test The two-tailed test is sensitive to differences in location (central tendency). in dispersion, in skewness, 25 etc. (Siegel, 1956, p.127). It is the best known of several distribution-free procedures which compare two (2) cumulative distribution functions in order to test for differences of any kind between the distributions of the populations from which the samples were obtained. The Kolmogorov-Smimov test is best used in situations where it is perhaps unclear what kind of differences to expect between populations, or where expected dif- ferences do not fit into the usual categories of location or spread (Neave and Worthington, 1988, p. 149-153). The Kolmogorov-Smimov test is probably more power- ful than the chi-square test in most situations (Conover, 1971, p 295). The most obvious advantage of the Kolmogorov-Smirnov test is that it is not necessary to group observa- tions into arbitrary categories; for this reason it is more sensitive to deviations in the tails of distributions where frequencies are low than is the chi-square test (Davis, 1986). The first method used a one-sample Kolmogorov-Smirnov test to evaluate the goodness- of-fit of each CSD to a normal (Gaussian) and lognormal distribution calculated from the mean and standard deviation of the CSD at hand. It was also used to evaluate the good- ness-of-fit of each CSD to a corresponding gamma distribution. The results of the test were evaluated by examining the significance level at which the null hypothesis (that the experimental and theoretical distributions are from the same population) could be reject- ed without a type 1 error. The null hypothesis was rejected if the significant level was less than 0.05. In the second statistical method, the CSDs for each sample were normalized by dividing each measurement by the corresponding CSD mean value. This placed each distribution at a central location equal to 1. The resulting difference in the cumulative frequency distributions of the CSDs would then only be characterized by the differences in shape or spread, and not in location. The CSDs were run through the two-sample Kolmogorov-Smimov goodness-of-fit test provided by the STATGRAPHICS statistical 26 program. Again, an arbitrary limit of 0.05 significance value has been selected, and the test data yield a general relationship of the CSDs. The third, fourth and fifth statistical methods yield numerical values which characterize the CSD shape. T-tests were conducted with these values to establish their similarity or difference as CSD shape characterizing values. The third statistical method calculated the normalized standard deviation (NSD) follow- ing work of Tweed, Hansen, and Ralph (1983). Tweed, Hansen and Ralph (1983) com- pared grain size distributions before and after recrystallization grain growth and noted that variances of distributions can be directly compared only if the distributions have the same mean. Since the data in their study approximated a lognormal distribution, the dis- tributions were normalized after scaling geometrically (Tweed, Hansen and Ralph, 1983, p.2237). The change in the normalized geometric standard deviation before and after grain growth could then be compared quantitatively. They followed the method described by Moore (1969). The CSDs in this study were not all close to lognormal and, thus, scaling them geometrically would not be appropriate. Therefore, the standard devi- ations of the normalized CSDs were compared in this study, and are termed the normal- ized standard deviations. The fourth statistical method used to characterize the CSD shape was skewness. Both the inclusive graphic skewness, as described by Folk (1980), and skewness calculated by the STATGRAPHICS statistical program are included in this study. The fifth statistical value characterizing the CSD shape is the gamma distribution shape factor alpha ((1) derived from each CSD using the STATGRAPHICS program. The general shape of the dolomite CSDs shows relatively low probabilities for intervals 27 close to zero, with the probability increasing for a period as the interval moves to the right (positive direction) and then decreasing at a more gradual rate as the interval moves further to the extreme positive region of the distribution. A class of functions that serve as good models for this type of distribution behavior is the gamma class. The gamma probability density function used in the STATGRAPHICS program is given by the equa- tion: f(x) = [3a xa-le-flx Na) where 0t is termed the gamma distribution “shape parameter” and [3 is termed the gamma distribution “scale parameter”, (Bury, 1975, p.299). The gamma F(a) function is defined by: I“ = Ixa"le”dx 0 The tails of the exponential, gamma, and lognormal distributions all decrease rapidly. For x large, the tail of the gamma distribution is dominated by the term e'X/B. Figure 10 (after Breiman, 1973) demonstrated the differences between the lognormal and gamma distributions where in each distribution the maximum of each occurs at x = l. 28 .f (X) //_\\ .5 _ / \ / \ / \ / \ .4 H ’ \ 2 —- I \ I I ' _ ’/’/ \QOGNORMAL / \\\‘ r’ 1 I 1 1 x o r 2 3 4 FIGURE 10 Densities of the gamma and lognormal distribution with parameters selected to give maximum value .54 at x=l (after Breiman, 1973). A series of gamma distributions is shown in Figures 11, 12, and 13, to illustrate the char- acteristics of gamma distributions with different alpha and beta values. Figure 11a illustrates the shape of several gamma distributions which have varying alpha values and a beta value of l, and 11b shows the corresponding cumulative frequency distributions of 11a. Figure 12a shows the shape of several gamma distributions which have a constant alpha and varying beta values, and 12b shows the corresponding cumulative frequency distributions from the gamma distributions in 12a. Figures 13a and 13b show the shape of the density distribution and the corresponding cumulative frequency distribution for several gamma distributions which have equal alpha and beta values. When CSD data is normalized, the value of the gamma distribution scale factor, beta, will become equal to the value of the gamma distribution shape factor, alpha.. The alpha value does not change between the normalized (NormSize) and directly measured (Size) CSD data. The alpha value defines the shape of the CSD in terms of the gamma distribution that best represents the CSD data, either as the directly measured data or the normalized data. 29 a Prob. Don-itu Fen. __ 2 1 Guam. -- 2.61 n". '- _‘-.. T-'_ '.-'--.' 3-71... ' u 3.51” . , 4 1' 1 a) .. I. X Cum. Dist. Fan. __ Gamma l buflyflfi O i‘ F ww- _ r '0‘--:7—;'.:.:7.3 oooo b ---- ' '. .3 1- b ... 1fi h 4 ... _—- ...—.._- .._... -' -—.—-' “_.— — —— —— — —— r- 1 b . p. d 0.. i- )- ’ 4 l r . d b 1 .0. ’— L . l 1 .- ‘. . q p q ... r— - .__ -- .._.-.1 p d 1- q p . 1 1 b l . I J x . A .L O I O O I. I. figure 11 a) frequency histograms, and b) cumulative relative frequency distributions of Gamma distributions using a constant B (scale) value and different a (shape) values. 30 Prob. Dun-itu Fen. a a — 3 .05 Gamma .. 3 .0. E ..... a 2: q e.e—- _ :I ~ 3 JJ ’ ‘ ‘ .d 0.6— : _: e . - « F i . '0 0.3— 1‘ _: e : : .0 ~ - 0 ea— _. L i I D. : . ...— L C I .P- — a, a 1 r 1 r . J r r 1 r 1 e a e u so to an X I a ‘ Cum. D&.te Fen. _ 3 ..s Gamm- " 3 .0. Y T Y '3‘ ru ° 3 108 ..... a 21 . d n . o _. L . O. . . d E — —I 3 J u .1 d bl : 1 " . e e e a u u on figure 12 a) frequency histograms, and b) cumulative relative frequency distributions of Gamma distributions using a constant a (shape) value and different 3 (scale) values. 31 Prob. Danastu Fen. __ 2.7 2.7 Gamma I - " 3 3 . ' r ' ‘ I i f ' 3.78123 * -- 3.3 aJe . ""° ‘0‘ ‘35 3 ' H—‘ . *J 4 '4 . < c ~—-——- 9' -- I . ‘D . O . .D o a L . a. ‘ 1 l l . - 1 a) . - . . . 0 I I 8 C O X . a a Cum. Osat. Fen. __ 2.7 2.7 Gamma °- 3 3 is ' ' L: are? e '- 3.8 3.8 ‘°°" ‘05 ‘15 . II .n . O --_.m" .._--"-___-_-_.-_ L . n. J O q E - --—- ;_ :r , . U ' ’ 1 _ _ _ m_- --- 14 ’_’"I‘;1'.'“'1“' ...L.... O I I l e I X figure 13 a) frequency histograms, and b) cumulative relative frequency distributions of Gamma distributions using equal a (shape) and B (scale) values. 32 It is evident from Figures 11b, 12b, and 13b that relatively minor variation exists between the cumulative frequency distributions which have equal alpha and beta values compared to the variations observed between cumulative frequency distributions where one gamma distribution variable (alpha or beta) is held constant and the other changes. The Kolmogorov-Smimov goodness-of—fit tests were completed between normalized CSDs, each of which have a beta value equal to its corresponding alpha value. Method Reproducibility For evidence of reproducibility in the line point count method, three CSD counts on each of two clasts within the Trenton formation core were conducted. Two CSD counts were also conducted on the Netherlands Antilles sample (BD6TS). Figure 14 shows two of thethree frequency histograms, and Figure 15 shows the respective cumulative frequency curves from the TLlA clast of the Trenton Formation. Figure 16 shows two of the three frequency histograms, and Figure 17 shows the respective cumulative frequency curves from the TLlB clast of the Trenton Formation. Figure 18 shows the frequency histograms and Figure 19 shows the respective cumualtive frequency curves from the Netherlands Antillies sample. The histograms and relative cumulative frequency distribu- tions are comparing the direct measurements taken (size) and are not the normalized dis- tributions (NormSize). It is evident from all of the histograms and cumulative frequency curves that relatively good reproducibility is obtained for the method. Similarly, a dupli- cate thin section sample of the same clast was made, and the grain sizes were measured as described above (clast/count TL4B and TL13B). The resulting frequency histograms are shown on Figure 20, and the respective cumulative frequency distribution curves are shown in Figure 21. Table 1 shows the two-sample Kolmogorov-Smirnov goodness-of- fit test significance levels for the respective clasts and counts. The significance levels indicate that the distributions are not significantly different. 33 Fraquanog Histogram I V r I v r 1 I Y 1 vi T I V if T froquancu 8 .....q....... L ,//’l l L . ac — \ j u - _ e r— —f"/' i l o—- '1 A L l 4 L l a I I. .0 .0 .0 no “0 TLlA.siza I I t I f I .0 '— _- u— L 1 m “L E 3: NH 2 m C _' . a": K - U L k. )— )- )- ‘l. I. .0 .0 II. “I TL192.aiza figure 14 Two of the three frequency histograms of line point counts of Trenton clast TLlA. (Note: size data is measured data and not normalized.) 34 Cumulatiua Ralatiua Fraquanciaa I r Y I ‘ ' I ' ' I r ' I ' T I {.0 '— _- L 4 t- .. P. —I L 1 +5 .. _ _ . L . u 1- at L r- d a a. t— — r d . 1 I. '— .— r. L . I— —___—/ _- J . - ' I l L 1 1; L ‘1. I. .0 a. I“ I“ TL19.arza l T I I 'Y I r I IO. _ u- q 5 '4 .0 — — L .. . / E .. l-D / «III m v- o‘ d u - - L . m u _- _1 0- t " '1 I. '- / -I )- '1 r- 1 . _ r I . r l . . l a A I a L 1 x x .l '3. .0 .0 on It. ‘6. TLlna.aiza figure 15 Respective cumulative relative frequency distributions of the frequency histograms of Trenton clast TLlA shown in Figure 14. 35 Fraquancy Hiatogram l I I I I r ' V I I I T r 4T r I v V l T umrs - r x 10' um . I ~ ‘ .4 h . O.- a— . a " ct h /1_ frequency 8 I l /l’ u— .— L 1 e — _J l a . l . . l . L L a 1 l . . I l ’3. I. . .0 ea “0 no I" TL18.siza , . ., - ., . ., - ., . ., .0 .— UNITS 2 1 x 10‘ um ..— J g..- \_ _' m "'s' __ ‘ 3 U \ U u— ' _ a \ . k . TL182.aiza figure 16 Two of the three frequency histograms of line point counts of Trenton clast TLlB. The solid line is a fitted gamma distribution. (Note: size data is measured data and not normalized.) 36 Cumulatiu- Rolatiu. Frequoncicn I I l T I fl I fi l IO. r— —: " ”' UNITS . 1 x 10' um — 4; «'- ‘ u b I U - . L D ‘ a I. I- - I. — _ O F'- o—" ‘ A l l A l l A l A I 'l. .0 u .0 I“ no I” TL18.sizc u l I l I f O 1 v . e -— _ u _ — . UNITS - 1 x10'um . *é’ .. L _‘ U ' . u p ‘ L b 1 u O. I.- .— 0. _ ‘ I. I— q . _ l L l J l A l 4 I L “I. I. .0 .0 “C It. 8?. TL182.sizc Figure 17 Respective cumulative relative frequency distributions of frequency histograms of Trenton clast TLlB shown in Figure 16. 37 Froqu-ncu Histogram ' 1 I v v I 1 I v v ' v V T I’ T 1 v Y 1 l ‘7 v v r I 60 UNITS O‘I1O‘Ufll .... r— _ 3 § r r _ 3 n“ _ .4 a . — . u p — d L _ — ‘ " ~ FL— . .L J r—r-m _ l L l l L l. il.l . I. I. a 6. I. 806Tstsize u— r If ' I v T UNITS-IxIO'um ao- [— r j m _ . U __ . c . m _— 3 ~- [— _ U’ U _r— L @- 806T82.sizo Figure 18 Frequency histograms of duplicate line point counts of Boi Doi dolomite from Aruba, Netherlands Antilles. The solid line is a fitted gamma distribution. (Note: size data is measured data and not normalized.) 38 Cumulative Relative Frequenciee I T I 'fi r If T I T I ' f I“ _- h- d b 4 I- q ..— e- b d I ums-uro'um ‘ p- -1 g “P- —I u + « u l- . L . n ‘0— d O. , . "l— a- r 4 h- d h 1 O— —I l A A A A 1 A A A A 1 L A A A l L A A A l A A A A l . I. .0 fl 6. .0 O BDSTS.saze T I I . \ 4 . I l 1 l l I l ' T ' I V V ' l I j— ' I I V 1 l ' V I l h \ I I A A A I A A A I t g .1 I BDBTSZ . Ii 2. Figure 19 Respective cumulative relative frequency distributions of the frequency histograms of the Boi Doi dolomite shown in Figure 18. 39 Frequency Hietograe f ' r r I I ' 1 I fl I .0 _- — r- d D C D q _ '- d u - umrs . Ix IO'um - b d ? F— el 3' ’ ‘ u- at g a '— — .- U ,_ ‘ b .. 3 _ r“ . g P _r_ -— d L " f r j 5— - F" . b e — b . I. b - v- e h ‘1 ,. .4 I I l d O —4 J- L A I A 1 l A L _A. l A A. ‘— 4 l I A L A l L J_. L L 'l. O. .0 I“ I” .0. a TL4B.srze I l I " I r T I .0 '— —I P C u- q r- d " __ UNITS - I x 10' um " a. — —I i- . 1 3| L _J— . U ’ ‘ a — _ E . . 3 i —' ‘ _ . r 1 U' _ f— . m n I— _ .— L . “ . ‘ P- u r- q I" d 8. _ - y- d D Q n d . m [‘1 - O '- 7 I- l 4 A A A I A A A A l A A #A l A A A A I A A A A l .I. O. .0 I“ b" .0. TL138.aize Figure 20 Frequency histograms of line point counts of duplicate thin-section samples of the same clast from the Trenton Formation. (Note: size data isnwmmmddflaamlmnnmmmmuflo 4o Cumulative Relative Frequenciee UNITS -1x10'vm percent O. i— .- " «I . I- I. '— _ h .. . . . . I D— -— A A A i L A A A l A A A A L - A A A l A A A A l '8. u .0 lea I” .40 . TL4B.srze I r t r T I f T ' IO. P— ____ _ i . . r- d a. — — ” ums - 1x10'um ‘ . - . - 2 ~- -' u * - 0 ~ - L > - Bl .. - _ D. _ . b -I p. . u — - . r . . . . . _. j 4 L I A l 4 g I 4‘ A l A L I 30 u .0 lo. I” .00 TL138.eize Figure 21 Respective cumulative relative frequency distributions of the frequency histograms shown in Figure 20. 41 TABLE 1 Two-Sample Kolmogorov-Smimov Test Evidence of Reproducibility On Measured Crystal Size Distribution Data Clast/Count K-S Significance K-S SnifiA— of Level of CSD Data Normalized CSD Data TLIAZ TL1A3 ' TLlAZ TLIAS .7870 .2098 ; .7870 .5175 .6527 § .5842 TL13B g TL13B .0659 , .517§ Boarsz g Bosrsz . .2923 T .2923 i Table 2 shows the comparative mean, the standard deviation, the normalized standard deviation, the skewness (as calculated by STATGRAPHICS), the inclusive graphic skew- ness (Folk, 1980), the value of the gamma distribution shape factor a (alpha), and the one-sample K-S significance value to the normal, lognormal, and gamma theoretical dis- tributions. 42 TABLE 2 Comparison of Statistical Values of Duplicate CSD Counts and Thin-Section Samples TLIA— 26.—— 88 16 49 .6134 1. 537 3.265 2. 700 11.1112 I 26.32 I 15.56 I .5914 I 1.004 I .169 5'0 .0634 MI .007 I .3302 I 2.613 TLlA3 27.34 16.98 .6208 1.231 .323 .0012 .158 .5011 2.581 “1* 1—6 20.94 .5669 1.639 .065 .0300 _ .0569 _——3—.038___— 1L1132 38.43 21.82 .5678 1.627 .157 .1900 .001 .0524 2.544 11.1133 38.51 23.01 .5974 1.301 .175 .0024 .0088 .3566 2.764 BD6TS 21.46 9.31 .4341 .0050 .0262 .3921 3.55-6 .0019 3.768 BD6TSZ 21.04 8.61 .4093 -.0808 -.0340 .2934 1.95.7 .0005 4.258 TL4B _______A_ 65.21 41.91 .6427 1.199 .278 .0023 .727 _. 2.382— 1L138 69.05 40.26 .5831 I 1.056 .205 .0005 .0987 .7293 2.824 ”“T- .. . o vratron ‘——"’ —“""————“————_‘ ' ‘ alpha = Gamma Distribution Shape Factor lGSK = Inclusive Graphic Skewness N = Kolmogorov-Smirnov Test Significance Level to a Normal Distribution SK = ST ATGRAPHICS Skewness L = Kolmogorov-Smirnov Test Significance Level to a Lognormal Distribution G = Kolmogorov-Smimov Test Significance Level to a Gamma Distribution The values presented in Table 2 show that relatively good correlation exists for the STATGRAPHICS skewness, the normalized standard deviation, and the gamma distribu- tion shape factor (alpha) as CSD shape descriptors. The mean and standard deviation values also indicate relatively good reproducibility of the line point count method. The size distributions obtained for the Trenton and Saluda Dolomites were compared to each other, and to the three computer—generated models. CSD measurements on the computer-generated microstructures of the Johnson-Mehl and site saturation nucleation and growth models, obtained from Dr. Knut Marthinsen, were also conducted by the line point count method. CSD DATA Trenton Formation ' In the Trenton Formation samples, CSDs of fifty-seven clasts in twelve thin-sections of core were measured. The CSDs within the Trenton Formation contained a range of mean grain sizes from approximately 103 um (microns) to 690 um. Table 3 lists the mean, nor- malized standard deviation (NSD), STATGRAPHICS skewness (SK), inclusive graphic skewness (IGSK), and gamma distribution shape factor alpha (a) of the gamma distribu- tions fitted to the CSDs by the STATGRAPHICS program. The table also shows the sig- nificance values for the one-sample Kolmogorov-Smirnov goodness-of—fit test of the normal (N), lognormal (L), and gamma (G) distributions, fitted to the Trenton CSDs by the STATGRAPHICS program; Almost all of the CSDs are coarsely skewed, and, as can be seen by Table 3, the skewness varies considerably between clasts within the same thin-section. There is no correlation between mean grain size and skewness. X—Y plots of the skewness, normalized standard deviation, and alpha values to the mean grain size values yield shotgun patterns. The mean significance level for goodness-of-fit to a normal distribution for the Trenton sam- ples is 0.046. Nine of the fifty-seven samples (approx. 15.8%) have a significance level greater than 0.05 for the Kolmogorov-Smimov goodness-of—fit test to a normal distribu- tion. The mean significance level for the Kolmogorov-Smirnov goodness-of-fit test to a lognormal distribution is 0.080. Twenty-six of the fifty-seven samples (approx. 45.6%) have a significance level greater than 0.05 for the Kolmogorov-Smirnov goodness-of—fit 43 AL4 TABLE 3 Trenton Formation CSD Statistical Values Normal Lognormal 0.0 l Alpha .69 89 .61313 2. 81 4 3.03783 2.54382 .76443 O 8 45 TABLE 3 (cont’d) Normal Lognormal Gamma Alpha 0.088 0.6169 .88956 3-0.002§-_ 0.0839 0.8383 3.24926 20.000034: 0.5184 0.122 2.64872 ‘7‘ I I: 0.222 0.2922 .68066 .68 . LI:.0,II3 ng.1} I ' 0.1573 2.18132 9 . . . . Q i. -‘ .6349 2.517 1 .45 . . ‘ ’II' 13.3 .0733 3.87437 .11 . . . 31.‘ _‘_i“‘ .6839 2.42907 .91 . . }I. .‘- 0. 0 9 .8156 3. 8985 .64 . . . ;D.V03piii 0.19866 .5798 2.71994 .79 . . . 70.120237, 0.07603 .3081 3.63656 .6 . . . 0.0804 y . . 7- .4353 3.62261 .07 . . . f7;7'-::j 70. ['71. .1945 3.66526 .26 . . . _ip.’: >fl,1 0.32612“ .4358 3.36934 .93 . . . J .‘13U-p; 0.05073 .6351 3.1558 .91 . . . '0.006545. 0.060908 .3966 3.79039 .53 . . . 3.0.43555H..8~ ‘_ ; phé. 1 4;: 4.55155 .54 . . . g '. ...: 02.;jhu‘i ut7l39‘. 260886 .43 . . . 370.60593.‘_. ‘3 .1509 2.37001 .63 . . . . .. l . . g . 36 . 7 4 .76 . . . I 0.05275755312 ‘1‘ 2.68302 .96 . . . T 0.09693 3.13785 .4 . . . 7' ; .4 r. 18 .75 . . . 20.099663, ".V H. 5: .3406 3.0576 .78 . . . L.T _ ->; ... p 75 .3212 2.8285 33.76 . . .35, i j; 03117445 .9593 2.13452 34.51 . . . :1. h_.¥";‘ 8“ .2773 2.5821? 33.79 . . . ii.rliT»;;'l0.37035x. .3932 2.0578 33.38 . . ’2' I ‘V:_'l .7 _(.fl: .5091 2.56273 13! 69.05 . 831 . 334.3‘:_§ 70.098746. .7293 2.82419 H.512. I Normalized Standard Deviation All.“ I Gamma Distribution Shape W I Kolmogorov-Smirnov Toot Significance Level to a Normal Distribution 93‘ I Inclusive Graphic Skewness W I Kolmogorov-Smirnov Test Significance Level to a Lognormal Distribution 5‘ I STATGRAPHICS Skewness Lima I Kolmogorov-Smirnov Test Significance Level to a Gamma Distribution 46 test to a lognormal disuibution. The mean goodness-of-fit significance level to a gamma disuibution is 0.440. Fifty-four out of the fifty-seven samples (approx. 94.7%) have a significance level greater than 0.05 to a gamma distribution. Table 3 shows that the gamma distribution has very few Kolmogorov-Smirnov goodness- of-fit values less than 0.05, and can probably best describe most of the CSD shapes rela- tive to the other distribution types. It is apparent that the gamma distribution shape factor may be a good value to represent the shape of each CSD, and can be quantitatively compared to determine CSD shape variability. The Trenton core sample CSDs were divided into two groups based on mean grain size to determine if trends in the shape of the CSDs were present in the alpha, skewness, and normalized standard deviation values of the two groups. A large mean grain size group and a small mean grain size group were evaluated. The small mean group contained those CSDs with a mean grain size between 113 and 313nm. The large mean group con- tained those CSDs with a mean grain size between 315 and 652 pm. A two-sample t-test was performed between the mean, alpha, normalized standard deviation, and skewness values in each group. A significance level less than 0.05 was used to reject the null hypothesis. The two-sample t-test between the alpha values resulted in a significance value of 0.15. The two-sample t-test between the normalized standard deviation values of the two groups resulted in a significance value of 0.56. A two-sample t-test significance value of 0.096 was obtained for the inclusive graphic skewness values of the two groups. The significance value for the two-sample t-test between the STATGRAPH- ICS skewness values was 0.98. The significance value for the two-sample t=test between the mean grain sizes was 5.3 E—l3. Thus, the null hypothesis that there is a dif- ference in the shape of the Trenton CSDs based on mean grain size is rejected. 47 Tables 4 through 10 show significance level results of the normalized CSD two-sample Kolmogorov-Smimov goodness-of-fit test between clasts from the same thin-section. The significance levels less than 0.05 are shaded. TABLE 4 Two Sample K-S Tests Between Thin-Section TL1 Clasts 1A3 I l I l 0. 70 0.5175 0.5842 0 5175 0.7212 ”.. : . 0.2923 . 4 . . .4 .4 0.7870 0.6427 .14 TABLE 5 Two Sample K-S Tests Between Thin-Section TLZ Clasts TLZB I TLZC 11.21) MA am: 99956 11.213 1 ”01.84175 N 06527 I 11.2c I 0.8475 TABLE 6 48 Two Sample K-S Tests Between Thin-Section TL3 Clasts Clast 11.38 TL3C TL3F TL3G 11.311 11.31 TL3] 1L3K 11.31. TL3M TL3A 0.3953 0.5175 0.1212 “0.0096 0.4543 0.6527 0.8996 0.7870 0.2485 0.7212 11.38 0.5842 0.1465 00007 0.1759 0.5175 0.2923 0.5842 3933737. 0.1759 11.3c 0.175910..02082 0.6527 0.3412 0.5842 0.7212 0.2098 0.6527 TL3F 00001 0.2485 0.3412 0.3953 0.3953 0.1212040424.’ TL3G ‘ 0.0530 00031 _‘2 0.0056 0.0162 0.042.400.0812 run “"6154; 6.7176 6.9566 "6.2485 6.15.. 3 11.31 0.7212 0.9408 }-0.0337 0.4543 11.31 0.7870 0.12485: 0.4543 11.311 0.0530 0.5842 11.3L 0.1465 TABLE7 Two Sample K-S Tests Between Thin—Section TL7 Clasts 1L78 11.71: TL7D 11.713 TL7A 0.2485 0.1465 0.1759 50.0013; 11.78 0.0659 0.3412 00208 TL7C 0.8475 00424 TL7D 0.0659 49 TABLE 8 Two Sample K-S Tests Between Thin-Section TL8 Clasts TL8D TABLE 9 Two Sample K-S Tests Between Thin-Section TL9 Clasts TL9B TL9C 11.9.4 0.2098 511.330.0424? ma 90162 TL9C TABLE 10 Two Sample K-S Tests Between Thin—Section TLll Clasts Clast TLllC TLllD TLllE TLllF TLllA 0.5842 0.8475 0.1759 0.6527 TLllB 99974 90973 07212 0-1212 1111:: 0.7212 0.2098 0.6527 TLllD 0.0996 0.6527 TLllE 0.2098 TLllF 50 From Tables 4 through 10 it appears that about one CSD (clast) is significantly different in shape from most of the other CSDs (clasts) in the same thin-section. The normalized CSD two-sample Kolmogorov-Smimov goodness-of-fit tests between all normalized Trenton samples are presented as a table in Appendix B. All two-sample Kolmogorov-Smimov goodness-of-fit significance levels less than 0.05 are shaded in the table of Appendix B. Of the 1,596 comparisons betWeen the Trenton clast CSDs, 1,290 (81%) show goodness-of-fit values >0.05. indicating that they are from the same popula- tion. Of the 306 comparisons (19%) with goodness-of—frt values <0.05, 174 (57%) of those are from 4 of the 57 clasts. The clasts include TLlD, TL2A, TL3G, and TL9C. The majority of the Trenton CSDs are not significantly different in shape from each other, though the mean grain sizes do vary significantly. Saluda Formation Eight CSDs from seven thin-sections of hand samples from the Saluda Formation were measured by the line point count method. The mean grain size of the CSDs of the mud- stones measured decreased down section, and ranged from 310m to 69 um. Figure 22 shows two of the eight normalized CSD frequency histograms. The normalized frequen- cy histograms of the CSDs are also included in Appendix C. Table 11 lists the mean, the normalized standard deviation (NSD), the STATGRAPHICS skewness (SK), the inclu- sive graphic skewness (IGSK), and the gamma distribution shape factor alpha (a) for the Saluda sample CSDs. It also lists the significance values for the one-sample Kolmogorov-Smirnov goodness-of-fit tests of the normal, lognormal, and gamma distrib- ution fitting to the Saluda Formation CSDs. 51 Pruquoncg Histogram 7" I 1 r *rfo'fi 11* 1 1 00'- —1 D d P d I _ I .0— .- D d [ ... ..__ 3 1. F—' . 3 “f — 1 C ’ ‘ a * ‘ 3 a:- +_ ...: . 1‘1- . U' 2 fl. llllll 1'1171 p L I. 1 1 1. 1 . . T. b llllLlJl 1 . f- T 1 1 ...—. —. 1- _ 1 1. . 1. a _ .1 3... ... h _. .1 a . __ . .- . 5 . _ . 3 ..- - 0' , -— - I . _‘ __ . k . . “- . . ae— -‘ 1- .1 . .1 . . . r n . e- n -1 1.4 L1. . . .1. L 4 l . 2 14—1 , . M88914DS.NormSizc Figure 22 Two of the eight frequency histograms of the Saluda dolomite samples. 52 TABLE 11 Saluda Formation CSD Statistical Values Sample Mean NSD SK IGSK Normal Lognormal Gamma Alpha b849OIDSSZ 68.905 0.4963 0.6592 0.2679 0.00004 , 0.004}; 0.2932 3.7044 MS4901DS.SH 67.253 0.4012 0.5253 0.125 :. 0.0001: W021! 0.0501 6.1786 MS4904DS 57.512 0.4530 0.7654 0.1145, 0.0873 0026? 0.2579 4.5784 MSB903DS 55.675 0.4978 1.055 0.1472 0.1551 00576 0.2013 3.8924 MSB904DS 53.801 0.4668 1.1053 .1515 0.02946 0.4254 0.5647 4.9075 MSB907DS 37.023 0.4990 0.7085 0.319 0.0049 0.1053 0.1373 3.9175 M58912DS 49.711 0.5217 0.6341 0.2661 15.0.0279 0.122 0.5755 3.4214 MSB914DS 30.741 0.5662 1.4115 0.4500 ,’;10..0001‘ 0.1005 35.0.0243 3.5505 m - Normalized Standard Deviation m . Gamma Distribution Shape Factor m1 = Kolmogorov-Smirnov Test Significance Level to a Normal Distribution 19.55 : Inclusive Graphic Skewness m1 = Kolmogorov-Smirnov Test Significance Level to a Lognormal Distribution SK 1: STATGRAPHICS Skewness mm s Kolmogorov-Smimov Test Significance Level to a Gamma Distribution All of the Saluda Formation sample normalized CSDs are coarsely skewed. Table 11 shows that skewness also varies moderately between the Saluda Formation samples. As with the Trenton samples, there appears to be very little correlation between mean grain size and skewness in the Saluda dolomite samples. The mean significance level for goodness-of-fit to a normal distribution is 0.035. Two of the eight samples have a significance level greater than 0.05 for Kolmogorov-Smirnov goodness-of-fit test to a normal distribution. The mean significance level for goodness- of-fit to a lognormal distribution is 0.108. Five of the eight samples have a significance level greater than 0.05 for Kolmogorov-Smirnov goodness-of-fit test to a lognormal dis- tribution. The mean goodness-of—fit significance level to a gamma disuibution is 0.263, and seven out of the eight samples have a significance level greater than 0.05. 53 Tables 12 shows the results of the normalized CSD two-sample Kolmogorov-Smimov goodness-of-fit test between the Saluda Formation samples. TABLE 12 Two-Sample Kolmogorov-Smimov Goodness-Of—Fit Tests Between Saluda Formation Samples Sample MS49OIDS. 1115490405 M88912 5 115391405 M58903 5 M58904DS 1115590705 11549010552 g;.g....,.;.;,»,.03.,...; 0.2533 0.4440 0.0940 0.4145 0.3644 0.2965 145490105511 0.3231 537;; .. , :j -__g-..- 1 _g .;;_:~.,; , , _ f 0.6578 .:I._,j:,-f ._.g __ 5154904135 5,31,. .. __ _.g 0.4653 0. 63 0.1053 M5891zos 0.700 0.2497 0.6240 11151191405 0.0968 ._ _j, 0.3896 M88903DS 0.5934 0.2030 MSB904DS 0.2382 was Of the 28 Saluda CSD comparisons, 7 (25%) show goodness-of-fit values <0.05. Of those 7, 5 (71%) of them are from the sample MS4901DS.SH. However, the majority are not significantly different from each other. Theoretical Computer - Generated Microstructures It is expected that the CSDs for the computer-generated models will vary according to the differing nucleation and growth parameters used to generate them. Those differences should be reflected in the differences in the appearance of the C805, and in the statistical values characterizing the CSD shape, as well as in the normalized CSD two-sample 54 Kolmogorov-Smimov goodness-of-fit tests. The normalized frequency histograms are also shown in Appendix C. The CSD for the site saturation model is finely skewed, the Johnson-Mehl model is more normally distributed, and the site saturation model with weakly clustered nuclei is quite normally distributed. Table 13 lists the statistical values for the theoretical models, as was done for the Trenton and Saluda Formations. TABLE 13 Theoretical Computer-Generated Microstructure CSD Statistical Values _ Normal Lognormal KMJNSMEL 0.2896 3 110.000.37.in I J KMSSWKCL 0000065 T KMSITSAT = Site Saturation (Cellul) Nucleation and Growth Model KMJNSMEL = Johnson-Mehl Nucleation and Growth Model KMSSWKCL = Site Saturation Model With Weakly Clustered Nuclei E512 = Normalized Standard Deviation Alpha = Gamma Distribution Shape Factor W = Kolmogorov-Smimov Test Significance Level to a Normal Distribution m 4: Inclusive Graphic Skewness mm = Kolmogorov-Smirnov Test Significance Level to a Lognormal Distribution SE = STATGRAPHICS Skewness 9.110.101 = Kolmogorov-Smimov Test Significance Level to a Gamma Distribution The gamma distribution shape factor does not adequately describe these distributions. The weakly clustered site saturation model is quite normally distributed. The Johnson- Mehl model is somewhat normally distributed, but is slightly finely skewed, as can be seen on Figure 6. The site saturation model is quite finely skewed and does not compare to a normal, lognormal, or gamma distribution. Table 14 shows the results of the two-sample Kolmogorov-Smimov goodness-of-fit test between the normalized CSDs of the three theoretical nucleation and growth models used in this study. 55 TABLE 14 Two-Sample Kolmogorov-Smimov Goodness-Of-Fit Tests Between Normalized Theoretical Computer-Generated Microstructure CSDs Model KMJNSMEL KMSSWKCL I KMSITSAT . ' ‘ 0.04524“ " .7 ‘- : . p L 0.053175}, 3:: .7 ' KMJNSMEL A I A H A H J ' ... 0.13512) The results of the statistical analyses of the theoretical models shows that the site satura— tion and Johnson-Mehl models differ according to the nucleation and growth kinetics used to generate them. As would be expected, the J ohnson-Mehl model has an increase in the frequency of smaller grains over the site saturation model (Figure 6). The effect of weakly clustered nuclei in a site saturation model appears to broaden the distribution, and to increase the number of small grains, thereby making the CSD less finely skewed than the site saturation model with random nucleation sites. The resulting weakly clustered model CSD mimics the shape of the Johnson-Mehl model, as can be seen by the Kolmogorov-Smirnov goodness-of-fit test value in Table 14, but it still maintains a lower frequency of the smaller grains than the Johnson-Mehl model. This illustrates the effect of varying the location of nuclei on the resulting CSD. Analysis and Comparison Between Formation and Theoretical CSDs The two-sample Kolmogorov-Smirnov goodness-of-fit values of the Saluda normalized CSDs to the Trenton and computer-generated normalized CSDs are presented in the table 56 of Appendix B. The goodness-of-fit values in Appendix B show that of the 456 compar- isons between the Saluda and the Trenton samples, 243 (53.3%) have values <0.05, indi- cating that those samples are not from the same population. Five of the eight Saluda samples account for 204 (84%) of the 243 goodness-of-fit values that are <0.05. These include MS4901.SZ, MS4901.SH, M84904, M8894, and MS8914. Thus, a majority of the normalized CSDs for the Saluda Formation samples are significantly different from those of the Trenton Formation samples. The means and standard deviations of the alpha, normalized standard deviations, STAT- GRAPHICS skewness, and inclusive graphic skewness values for the Trenton and Saluda CSDs are presented in Table 15 TABLE 15 Comparison of Mean and Standard Deviations of the Means and Standard Deviations of the Alpha, Normalized Standard Deviation, Skewness, and Inclusive Graphic Skewness Values for the Saluda and Trenton Formations SALUDA FM. CSD Shape Descriptor Mean Standard Dev. ‘ 5131193! 0 Dev. Alpha 21.269 0.923 0,542 Normalized Standard Dev. 0.488 0.049 0.107 FTATGRAPHICS skewness 0-353 0302 1.089 0.222 0.087 0.1 17 This table shows significant differences between the alpha values of the two formations, and between the normalized standard deviation values of the two formations. There is moderate-to-low difference between the STATGRAPHICS skewness values between the 57 two formations, and very little difference between the inclusive graphic skewness values of each formation. Two—sample t-tests performed between the shape descriptors of the two formations resulted in similar conclusions. Significance levels less than 0.05 result in rejection of the null hypothesis. The two-sample t-tests for the alpha and normalized standard deviation values of the two formations yielded significance levels of 1.7 E9 and 0.0015 respectively. The two-sample t-test for the STATGRAPHICS skewness and inclusive graphic skewness values of the two formations yielded significance levels of 0.1853 and 0.8184 respectively. The table in Appendix B also shows that the theoretical model CSDs are significantly different from both the Saluda and Trenton Formation samples. There are no goodness- of-fit values greater than 0.05 for the site saturation model. The Kolmogorov-Smimov goodness-of-fit tests between the weakly clustered site saturation model and the Trenton Formation samples have only two significance values greater than 0.05 out of the 62 comparisons. Kolmogorov-Smirnov goodness-of—fit tests between the weakly clustered site saturation model and the eight Saluda Formation samples resulted in only one signif- icance value greater than 0.05. The J ohnson-Mehl model goodness-of-fit to the Trenton Formation samples resulted in nineteen significance values greater than 0.05 out of the 62 tests. Three of the eight goodness-of-fit tests between the Johnson-Mehl and Saluda Formation samples resulted in values greater than 0.05. This indicates that the J ohnson- Mehl model is the closest of the three theoretical models to the dolomite CSDs, but all theoretical models have relatively poor representation of the experimental data. DISCUSSION CSD shape comparison between the Saluda and the Trenton samples appear to show the Saluda Formation sample CSDs have slightly lower frequencies of very small grains. Figure 23 is a cumulative frequency graph of Saluda and Trenton Formation samples which illustrates the CSD behavior observed between the two formations. c.o.1=.'a -—- TL11£.NortaSiz¢ .4 H3091408.Nom3 ' W V 1 1—7 r 1 v T Y —r 1* r V mr Y t 8 ... A c.d.f‘. A; L A. 1 A] A 4 1 # A L A 1 g; 4 J L I 8 I 3 ubscruatian FIGURE 23 Kolmogorov-Smirnov goodness-of-fit test cumulative relative frequency distribution showing the consistent differences between the Saluda and Trenton Formation CSDs. The lower number of small grains in the normalized Saluda sample CSDs, relative to the 58 59 number observed in the Trenton, implies a lower nucleation to growth ratio in the Saluda Formation than that of the higher temperature Trenton Formation samples. It cannot be determined if the lower ratio in the Saluda is due to a decreasing nucleation rate, an increasing growth rate, or both, relative to those of the Trenton samples. Occasionally, much larger grain growth, also termed “run-away growth”, is also evident in the higher temperature Trenton samples, and can be associated with elevated temperatures. Run- away growth was not observed in the Saluda Formation samples. The values of skewness did not show significant differences between the Trenton and Saluda samples, as is evident by the two-sample t-test results shown previously, as opposed to the gamma distribution shape factor alpha. It may be that the skewness fac- tors do not detect significant differences between the CSDs due to the nature of the skew- ness statistic. Groeneveld (1991) compared several measures of skewness of univariate distributions, and used Hampel’s influence function to clarify the similarities and differ- ences among the measures of skewness. “Skewness, like kurtosis, is a qualitative proper- ty of a distribution... A general concept of skewness as a location- scale-free deformation of the probability mass of a symmetric distribution emerges. Positive skew— ness can be thought of as resulting from movement of mass at the right of the median from the center to the right tail of the distribution together with movement of mass at the left of the median from the left tail to the center of the distribution,” (Groeneveld, 1991, p.97). The steps outlined by Hartmann (1988) indicate that the gamma distribution shape factor (alpha) and the normalized standard deviation values may be better descriptors of the CSDs than skewness values. “Instead of using a goodness-of—fit parameter to some- thing which is only assumed, I propose the following procedure: 1) Make a decision about the statistical system, thus, the right descrip- tive statistics to be used. 2) Estimate the parameters of the experimental data. 60 3) Check the goodness-of-fit to the theoretical distributions for the pur- poses of quality control,” (Hartrnann, 1988, p.915). Use of the gamma disuibution in describing CSDs is also supported in work by Vaz and Fortes (1988) in which they show the gamma distribution to have the type of asymmetry observed in actual grain size distributions. The majority of CSDs in this study do not resemble lognormal distributions. It is com- mon to find lognormally shaped CSDs in materials believed to have undergone aggrad- ing neomorphism by Ostwald ripening (recrystallization due to surface free energy differences whereby large crystals grow at the expense of smaller crystals). An aggregate of grains can reduce its total interfacial free energy by forming grains as large as possi- ble, thereby reducing the total interface area (Vernon, 1975). The Trenton and Saluda Formations do not have lognormally shaped CSDs and do not show petrographic evidence of neomorphism. Recent dolomite crystal size distribution studies (Gregg and Howard, 1990; Gregg and Shelton, 1990) have found lognormally shaped distributions in dolomites. Using the line point count method with scanning electron microscopy, Gregg and Howard (1990) determined CSDs on Recent dolomites forming in peritidal savannahs on the Caribbean island of Ambergris Cay, Belize. The Belize samples had an average Kolmogorov-Smimov goodness-of-fit test significance level of 0.17 to a normal distribution, and 0.58 to a gamma distribution, whereas the average for a lognormal dis- tribution was 0.69. Only two of the normal disuibution tests had significance levels less than 0.05, and none of the lognormal or gamma distribution tests had significance levels less than 0.05. The submicron to micron sizes of the Belize dolomites are within the range in which surface free energies can contribute to the stability of a crystal. The log- normal distributions are therefore consistent with the hypothesized Ostwald ripening process. Gregg and Shelton (1990) also determined the CSDs of the back reef facies 61 dolomite of the Bonneterre Dolomite in southeastern Missouri. The Bonneterre Dolomite forms the lower part of an upper Cambrian platform carbonate sequence which is a pri- mary host to the Mississippi Valley-type sulfide ore deposits of that region. The resulting CSDs were all coarsely skewed and typically lognormally distributed. The Bonneterre samples had a mean Kolmogorov-Smimov goodness-of-fit test significance level of approximately 0.14 to the normal distribution, and 0.25 to the lognormal distribution. The lognormal distributions observed in the Bonneterre dolomite could be attributed to further dolomitization and neomorphism during the sulfide mineralization. It is assumed, for lack of other evidence, that the neomorphism was driven by surface energy (e. g. Ostwald ripening) during the regional mineralization. The lack of neomorphism in the Saluda dolomite is suggested by the presence of well preserved CL zoning. The dolomite probably did undergo partial re-equilibration of unstable cores. However, that would be a compositionally driven process and not a surface energy driven one. The thickness of contemporary CL zones can be used to distinguish flux-limited crystal growth from surface-reaction-limited crystal growth (Kretz, 1974; Carlson, 1989). Heterogeneity in the flux of dolomitizing solution is based on Pingitore’s (1982) concept of macropore and micropore solute transport. In macropores the solute may be transport- ed under hydraulic gradient whereas in micropores, or in isolated intragranular pores which form culs-de—sac off the flow path, the solute is subject to transported by diffusion. The chemical isolation, and the ability to exchange ions between these two water/solute regimes, determines the openness of the system to dolomitization, the degree of textural preservation, and the resulting trace-element chemistry of the dolomite. Assumptions made for this model are that for most of a given volume of rock solute transport is by dif- fusion, that a much smaller volume receives solute by advective flux, and that there is a continuum between advective flux and diffusion flux. In flux-limited crystal growth, contemporaneous CL zones in crystals of different sizes will vary with the radius of the 62 crystal. The larger grains presumably receive a greater flux of solute from which growth occurs, and will grow at a quicker rate than smaller grains, which receive a smaller flux of solute. The larger grains will subsequently grow thicker CL zones than those of the contemporaneous smaller grain CL zones. In surface-reaction-limited crystal growth, the contemporaneous CL zones will have a constant thickness regardless of the crystal diam- eter. The variation in crystal size results only from the age of the crystal. Nordeng and Sibley (1990) conducted such a study on the Saluda Formation dolomite and found that the contemporaneous CL zone thicknesses were a function of the crystal diameter, and therefore fit a flux-limited model. The theoretical models indicate that the CSD skewness could be augmented if the preferred nucleation sites were slightly clustered, and not homogeneously or randomly distributed. Qualitatively, only clast TLlD, and possibly TL3G, of the Trenton dolomite clasts had noticeably ‘clustered’ sizes. Petrographic inspection suggests that these clasts may have initially incorporated two textural sizes within them, because groups of small dolomite crystals were distinct and did not necessarily grade into the surrounding larger crystals, as seen in the theoretical model. The CSDs for these clasts were among those most different from the other Trenton CSDs. Clustering in the Saluda was not apparent. CONCLUSIONS Several characteristics of the CSDs observed in this study can be noted. 1) 2) 3) 4) The CSDs for almost all samples are coarsely skewed with the exception of the computer- generated microstructures. The shape of the majority of CSDs for the Trenton and Saluda Formations are represented more closely by the gamma-type distributions than they are by the lognormal or normal distributions. This is evident by the greater percent of Kolmogorov-Smimov goodness-of-fit values >005 for the gamma distributions than the lognormal or normal distributions. The majority of the Trenton CSDs have a similar shape regardless of their mean grain size. This is evident by the 81% of the goodness-of-fit values >0.05 between Trenton samples, and the two-sample t-tests of the mean grain sizes, and the alpha values between the large mean grain size Trenton clasts and those of the small mean grain size Trenton clasts. In addition, the X - Y plots of the alpha and NSD values of all Trenton samples against the corresponding sample mean grain size values showed no linear trends. The shapes of the majority of the Trenton CSDs show significantly different dis- tributions than those of the Saluda Formation. This is evident by the mean and standard deviation values of the respective alpha and normalized standard devia- tion CSD shape descriptors, and a two-sample t-test conducted on those values. It is also evident by the 53.3 % of the goodness-of-fit values <0.05 between the Trenton and Saluda samples 63 64 5) The mean dolomite crystal size decreases down section in the Saluda Formation. This down section decrease in mean grain size is consistent with the flux-limited growth identified by the Nordeng and Sibley (1990) CL zone thickness study. 6) Lognorrnally shaped CSDs may be supplemental evidence of neomorphism of dolomite. This is evident by the lognormal distributions of the Belize modern dolomite and the Upper Cambrian, Bonneterre dolomite CSD studies by Gregg et al., and by the lack of evidence of neomorphism in the Saluda samples. 7) CSDs of the computer-generated microstructures do not resemble those of the Trenton or Saluda Formations. Further study of the limestone Trenton clast CSDs would be required to compare the dif- ference between the dolomite and precursor limestone CSDs. A similar relationship between the mean grain size and CSD in the limestone clasts as observed in the dolomite would indicate that the precurson limestone texture exerts significant control of the nucleation and growth of the dolomite. In addition, further studies in similar geologic settings are needed to determine if the differences between the Saluda and Trenton sam- ples are a consistent characteristic of CSD shape between the different settings. APPENDICIES APPENDIX A Thin-Section Descriptions, Photographs, and Drawings APPENDIX A Thin-Section Description, Photographs, and Drawings We: L1- 12 C3 1321 4931: (TLl) Elm 129591100921 ; one pop> Fine to medium grained, planar dolomite. Fine to medium grained, planar dolomite. Very-fine to fine grained, planar dolomite. Very-fine to fine grained, planar dolomite with a few large echinoid replaced grains. some clays and minor porosity. Medium to coarse grained, planar dolomite. Fine to medium grained, planar dolomite. Fine to medium grained, planar dolomite with a silica replaced brachiopod. small amount of anhydrite and some clays which allowed more plucking from minor porosity. TL 1- 12 C3 855 4891: (TL2) Ll- it I' r; or m pow >_pow ? Coarse grained planar dolomite with some plucking during sample preparation. Medium to coarse grained, planar dolomite. Fine to medium grained, planar dolomite with some plucking. Medium to coarse grained, planar dolomite with some plucking. 2 C1 Bl: (TL3) Medium to coarse grained, porous, non-planar, with significant clays between crystals. Vug? Fine to medium grained, planar dolomite. Fine to medium grained, planar dolomite. Fine to coarse grained, porous, non-planar dolomite, with some anhydrite and significant clays between crystals. Vug? Fine to coarse grained, porous, non-planar dolomite, with some anhydrite and significant clays between crystals. Vug? Very-fine to fine grained, planar dolomite. Dirty, with pyrite. Fine to medium grained, planar dolomite. ° Medium to coarse grained, planar dolomite with minor porosity. Fine to medium grained, planar dolomite with some porosity between clasts; 65 66 f-a Medium to coarse grained, planar dolomite with some porosity between clasts. Medium to coarse grained, planar dolomite. Fine to medium grained, planar dolomite with some clays between crystals and minor porosity. . Medium to coarse grained, planar dolomite with an area (vug?) of fine to medium grained, porous dolomite which has more clays. N. Medium to coarse grained, planar dolomite. L1-12 C3 B2. (T134) A. Coarse grained, porous, planar dolomite with a few anhydrite grains and some plucked grains. B. Coarse grained, porous, planar dolomite with some plucked grains. No anhydrite grains. Ll-12 Cl BS: (TLS) I(. Coarse grained, porous, planar dolomite with some pore filling clays, much anhydrite and plucking. L. Medium to very-coarse grained, porous, planar dolomite with some anhydrite, pore filling clays and plucking. "' W. Fine to medium grained, dirty, planar dolomite(?), with minor porosity (in one area), some plucking and a stylolitic boundary. Luck 1-12 C1 BS 485?: (TL6) * 11. Medium grained, porous, planar dolomite with some plucked grains. (Same as TL7E) Partial? L1-12 C1 BS: (TL7) A. Fine to medium grained, porous, planar dolomite with a moderate amount of clays and silt size quartz grains in the pore spaces and between crystal grams. Medium to coarse grained, porous, planar dolomite with a few large, run-away growth dolomite rhombs, and minor amount of clays in the pore spaces. Medium to coarse grained, very porous, planar dolomite with an appreciable amount of anhydrite and pore filling clays. Medium to coarse grained, very porous, planar dolomite with some anhydrite and pore filling clays. Fine to medium grained, porous, planar dolomite with a minor amount of pore filling clays. Luck 486495 (C 1 B8?): (TL8) A. Fine to medium grained, moderately porous, planar dolomite filling a fossil mold and non-mimetically replacing it. A moderate amount of pore filling clay and a small amount of anhydrite. B. Fine to medium grained, slightly porous, planar dolomite with a minor amount of pyrite. C. Fine to medium grained, porous, planar dolomite with a minor amount of pyrite. D. Medium to coarse grained, very porous, non-planar dolomite with a moderate amount of anhydrite. 3!"?5 1719.0!” 67 E. Fine to medium grained, slightly porous, planar dolomite with a moderate ' amount of clays in the pore spaces, a minor amount of pyrite, and a dingy appearance. F. Fine to medium grained, slightly porous, planar dolomite with a minor amount of pyrite and a dingy appearance. G. Fine to medium grained, planar dolomite with minor porosity,, a minor amount of pyrite, and a dingy appearance. Luck 1-12 C1 B5 4852172: (TL9) (same as 6, 7, and S?) A. Fine to medium grained, porous, planar dolomite with a minor amount of pore filling clays. B. Very-fine to fine grained, moderately porous, planar dolomite with a significant amount of clays in the pore spaces and between grains. Some anhydrite and a large, replaced echinoid grain. C. Medium to coarse grained, porous, planar dolomite with a minor amount of pore filling clays. D. Medium to coarse grained, porous, planar dolomite. Luck 1- 12 C3 BS 4891: (TLlO) (same as TL2?) A. Coarse grained, porous, planar dolomite. B. Medium to coarse grained, porous, planar dolomite. C. Coarse grained, very porous, planar dolomite with a minor amount of pore filling clays. Luck 1-12 C2 B1 4867: (TLll) A. Medium to coarse grained, very porous, planar dolomite, with a minor amount of pore filling clays. B. Fine to coarse grained, very porous, planar dolomite, with an appreciable amount of pore filling clays. C. Medium grained, porous, planar dolomite with a minor amount of pore filling clays. D. Medium to coarse grained, very porous, planar dolomite with one large calcite crystal, and a minor amount of pore filling clays. E. Medium to coarse grained, porous, planar dolomite with a minor amount of pore filling clays. F. Medium to coarse grained, moderately porous, planar dolomite. G. Medium to coarse grained, porous, planar dolomite with a minor amount of pore filling clays. Luck 1-12 C3 B21: ('1‘L12) A. Fine to coarse grained, very porous, planar dolomite with an appreciable amount of pore filling clays and a few, very large, replaced, echinoid grains. Ll-12 C3 B2 4882: (TLl3) (mirror of TL4B) A. Same as TIAB, but with an anhydrite grain present and also a heavier amount of pore filling clays. 68 SALUDA Formation Samples 3-28-89 #4 #7d #7 #15 #20 #22 #23 Very fine to fine grained, non-planar dolomite with minimal porosity. Fine grained, non-planar dolomite with minimal porosity. Partially dolomitized section of thinsection. Very fine grained, mudstoned. Grainstone with partially dolomitized matrix between, or within some allochems/grains. Non-planar dolomite with some echinoid grains replaced. Partially dolomitized area, euhedral dolomite, some of which outline former grainstone particles/allochems. Rhombs are cemented within, or growing within, large calcite crystals. Some pyrite and si, especially near contact with the completely dolomitized area. Completely dolomitized area, non-planar, very fine grained with occ. glaucanite grain, and laminations. Nearly completely dolomitized. In areas where there is some calcite cement, the grains that are completely dolomitized appear to be non- planar. There are a few fossil molds replaced with calcite cement and are partially dolomitized. Grain Mount Method #22 One large piece of partial dolomite was soaked in a 1% solution of HCl for 4 days. The solution was changed approximately every 12 hours by decanting the old solution without disturbing the sediment. The large sample was removed and the sediment was removed with an eye dropper, placed on a slide and allowed to air dry. This residue was then brushed onto a slide coated with Canada balsam for measurement. TL - 1 (TL 1 - 12 C3 B21 4931) TL - l CLAST DRAWING 70 TL-2 (TL1-12C33554891) TL - 2 CLAST DRAWING AST DRAWING 72 TL-4 (Ll-12C3324882) “’1 TL - 4 CLAS'I' DRAWING 73 TL~5 (LI-IZCIBS) TL - 5 CLASI‘ DRAWING 74 TL-6 (LUCKl-12C135485?) TL - 6 CLASP DRAWING 75 TL-7 (Ll-IZCIBS) TL - ‘7 CLAST DRAWING 76 TL - 8 (LUCK 4864175 C1 B8?) TL-8 CLASTDRAWING 77 - 12 C1 BS 4852%) TL - 9 CLASI' DRAWING 78 TL - 10 (LUCK 1 - 12 C3 BS 4891) TL - IO CLAST DRAWING 79 TL - ll (LUCK I - 12 C2 31 4867) TL - 11 CLAST DRAWING 80 TL-IZ (LUCKl-12C3821) TL - 12 CLAST DRAWING 81 TL-l3 (Ll-12C3324882Hmln’orofTL-4) TL - 13 CLAST DRAWING APPENDIX B Two-Sample Kolmogorov-Smirnov Goodness-Of-Fit Tests LPPENDIX B “ov-Smirnov Goodness-Of-Fit Tests .. 300. . _ 09.0.0 L 005.0 80nd 05nd N 3.5.0 800.0 500.0 88.0 300.0 000 «.0 053.0 «13.0 .5... IS... 05... 0:20. wSF a 5k v _.vmd «09.0 180.0 _. $0.0 «a x . 580.0 mevod . m 0% 09.3030. 0.20226. 53:020. 903 50 500.0 400 8:0 80 a. 1% 1 11““4H «30.0 800.0 «30.0 wt: y... ...»... .. . . . H .... 05... «:40 008.0 030.0 05.0 22.0 09 800.0 99.0 9.90 92.0 a1. l.1|1 88.0 800.0 508.0 250 «05» 033 05.0 81.0 800.0 900.0 02 99.0 800.0 83.0 9.80 0:00 9:0. 990 000.0 88.0 9.8.0 002.0 92.... «5.0 020.0 «30.0 020.0 2.05.0 <5... 05» 8:» SS» 9.: 05.: «<50. 5: 280030 82 TWO SAMPLE KOLMOGOROV - SMIRNOV TEST FOR NORMALIZED CSD'S (size lave. size) 5150 .L 113-50-ssaup005) AOUleS—A0.10301u[0)l aldums-oml fl XIGNEIddV TWO SAMPLE KOLMOGOROV - SMIRNOV TEST FOR NORMALIZED CSD‘s (size / ave. size) TWO SAMPLE KOLMOGOROV - SMIRNOV TEST FOR NORMALIZED CSD's (size / ave. size) 178 TWO SAMPLE KOLMOGOROV - SMIRNOV TEST FOR NORMALIZED CSD's (size / ave. size) <0.0S 98 TWO SAMPLE KOLMOGOROV - SMIRNOV TEST FOR NORMALIZED CSD's (size / ave. size) 0.1212 0.6527 TWO SAMPLE KOLMOGOROV - SMIRNOV TEST FOR NORMALIZED CSD'S (size / ave. size) [.8 APPENDIX C Normalized Crystal Size Distribution Frequency Histograms and Crystal Size Distribuiton to Thin-section/Sample Key APPENDIX C Normalized Crystal Size Distribution Frequency Histograms And Crystal Size Distribution To Thin-Section Sample Key THIN SECTION NAMES FOR CSD GRAPH NAMES Gilliam: W Slims Trenton Formation, Jackson Co., Michigan TL-l TL 1 - 12 C3 B21 A-I 9 TL-2 TL 1 - 12 C3 855 4891 A-D 4 TL-3 L l - 12 C1 Bl A-C.F-M 11 TL-4 L l - 12 C3 B2 AB 2 TL-S L 1 - 12 C1 BS K,L,W 3 TL-6 Luck 1 - 12 C1 BS 485? H l TL-7 Total Luck 1 - 12 C1 BS 485? A-E S TL-8 Total Luck (C1 B8 ?) 4864 1/2 A-G 7 TL-9 Total Luck 1 - 12 C1 BS 4852 “2 AD 4 TL-lO Total Luck 1 - 12 C3 B5 4891 A-C 3 TL-ll Total Luck 1 - 12 C2 B1 4867 A-G 7 TL-12 Total Luck 1 - 12 C3 321 A 1 TL-13 Total Luck 1 - 12 C3 BZ 4882 B 1 (Mirror of TL4B) Netherland Antilles, Aruba Dolomite BD6TS BD6 (Boi Doi Thin Section, two CSD counts) BD6GM BD6 (Boi Doi Grain Mount, one CSD count) Saluda Formation, Jefferson Co., Indiana 4901.82 MS4901DS (500 grain CSD count) 4901.811 MS4901DS (445 grain CSD count) 4904 MS4904D8 893 MS893DS 894 M8894DS 897 M8897DS 8912 M88912DS 8914 M88912DS Computer Generated Microstructures KMSITSAT Site Saturation (Cellular) Nucleation and Growth KMJNSMEL Johmon-Mehl Nucleation and Growth KMSSWKCL Site Saturation Nucleation and Growth With Weakly Clustered Nuclei 88 frequency frequency 89 L "ii i).— . I '1L—i—q‘l—i {—7 TLlA.N0rmSize l '1 l 1 1 l r 1 . 1 l 3 l -I.l 0.. LI ... TL192.N0rmSize 90 J1141|4|14IJJ|4|1— . «J 4 _ .1.JJ _ a q a 4 A O _ . q a _ . a a d 4 q 0‘— l L 6. ft 1 . . e . L e . . L .. L. . . m e i L . . . m U .. h L e Z - 1 . em 1 .2 T - 1 .1 a. I m 1 L E r i 1 .. . a . - _. N - II L . L . 1 .. m . . _ W1 . 1 i T . L 1 1 L r _ . T . . e . F T _ 1 .. _ . . w . . .7 H r. v r — 1 V W i 0. I 1 # L . FIE: . L . - .2 r . T—lLLiLlLiL- rrr r.._LLlel_! . - [thlLiPLiPLIL [1-1. - L .. ...- _lir _ . _ . F L b u u u ... ... . u u « ... JUCIJUILt Janina-LL 8.. TL18.N0rmSizc 91 11. - .I‘ -1.—|4ldJIaidiflli_ ._lJIdI .1—1111Jl—I-J13# TL182.N0rmSize mucmjfiuah — 1.11_._ _ _1— 7—44..qu .... ‘I_|‘wlal—1-i—.1<. _t— -1_.i# _ e —\ _ - _ _ . .LLILIPLlrLlrhiEiEi—LLIPLIEEFM _ n u u a n u 6 JUCUJUULL TL183.N0rmSize 92 JOCIJUILk 1110114114191—1.‘ 14411—141414: ._..—11141 .4141._ 1.1111 jj T 1 I I L _ _ _ . e - T - 1 _ e L e j . rt — b|b r r b p b p r — p b h u — p p p p F b n n n h u u a u .6. 6 8.. TL1C.N0rmSize 8.. r— JDCIJUILh A. 88 ‘8 TLlD.N0rmSizo 93 i—‘ldlll~)i -|_‘ 111 rfiJl—ll1 11— I 1—[411141'4'11—11 mucujwflak TLlE.N0rmSize e TL1F.N0rmSiz- i—IJIJZ - |_ .q ...I-Ilel-HI1'1I-llflvu—J’wtldllfl .11.. . 111-.1—1 L 3 h . 4 L W. 4 fl _ _ .. _ F1|I| . . H - _ r . _ _ . _ . . . . 0 u a .6. u a JUCIJUILh 94 IAIJI— . .1— _ giniJi—JIIAI- _.—1Il_ J...‘ ._l_|_.l _l‘ I I.__L.L-LA|,.I L..J 4-1 A I I l l JA_l -.l ——L——l—u 101 .II. I ‘ I . .' ; I'D ll. 1! II V ‘IV .I‘ II. n j I .l ‘v . . I ‘l ‘1' .JJI ' J] a. _ - _ d Jluld‘ll— _ a la Jl— «I'd J q IH II— fill- . . - Inn .Jllldl— n nlfll‘ild a 4'1 [—l—ll—l TL3K.NormSizc _r7 [I LL TL3J.NormSLz¢ V A A . I l I I I1 I # T A . rl- 4HI. 4 v rill it}! . I'L .rl—llrrlbo.—PL»k—.>»p—-»F.FLI —».,.._P.»»_.-..—F».» . u a u .o. u u n u o JUCIJUILh JOCOJUILh 1' IL V. I u 102 j r r fill LLLIPL u u _l JUCUJUULh JJIdJIIfiI—l11nlfildl1djll—1— .14'JJ1_ 11.!- 1‘. 3411—1 .b. EtLtLl—ILI - .rr~ 1% - TL3L.NormSizc fil—l. I4 _ _y‘111141-1.llq11-,‘.l~. 4.1—.14....‘14;1_l.—1 . TL3M.NormSizo JUCIJUILh KB JijldJI— «J . .1 — q q 4 41—--. 1111—.111-14. 4.1—-.4 . .. _lnllll‘ob :1 .le . ,- . . -. 1 _ . . . . _ . _ - . d - - 410.4 _ a J . . d# TI r 1 A , I A A . A H 1 fl A r TL4A.NormSizc TL4B.NormSizo . T l h . hrLLf—pp.»—»|PP~__».V—*lplphr —. p p P— p . b p — . . u p — . p p . u a u a H O O O N O O O 3 I JUCUJUILL JDCIJUILL TLSK.NormSizc JJIqu. . . . _ a _ 4 q firwJJJJ; f _L r i t We A ._ T _ _ 1’. _ . — . _ . _ —l u n u a n n o JUEmJUULL . “_‘l‘fit _‘14 |..1,.11_1J1\_ 1 — h p b — p n p JUCIJUILh 1.. TLSL.NormSizc frcquoncg froqucncg O. 8. MB I Y Y Y I * T I * l ' ' ' I I _ _ L F“ J _ 4 1 b- —I ‘- l — .- 1 " ‘1 ~ J 1 P G r—— —— J b _ . P—-‘ i _ I L. .. . 4 . 1— _ -; F 7 ’ '1 p- -‘ _ 1—, _1 - . 1 1 1 - _ 1 1 l I 1 r1 _' 1 A 1 A A J 1 L A . 1 L A L ' ..0‘ .0. ‘0. .0. 3.. O TLSU.NarmS;zI 1 T I Y V f f T j ? —— .3 1 ... ‘IY1U'T'Y'r7TI‘IIYrIII'rYfiT _1 J r- 1. 1 1 1 r TLBH.NormSizc _.l._n -u _AL..I...' 4.1.1 .I .1-|-4_.1...I..1._|--a. s u 1 106 J11-.I~ _ _ ...l--.x _.1‘.J..-qII—I.— ... .. 191— ,_1‘- ‘1.1-.... .14. v—# 1 Y L r F 1 A F L l 1. 1 bP-bb—pbh»—bpbPPb-P-—-PPP—rPF-r “ . . a n . . . t I JUCIJUILL 8n. TL7A.NormSiz¢ 141111.411 . .._ -. q. u — d W q _ 4 q — J11! 411-111 # I .0 F— 80 r— O JUCIJUILh It TL7B.NormSizo 107 4141-1d141.— u . . «141. q 41‘ Tq11q _.IJL..|41.IJ O 11114-- 41 q . «1— q 4 a . —1- q 1.14 d 1.141411 r. . I J v I _1_ Hm TL7C.NormSiz¢ TL7D.NormSizo f v r Flllllll'u'l A _1 .. I IA .- T i o F p h h b h P P rh — P b b h — h h h P h p p h b L — — — .1 .11bl » PL b — b h h h — b h b P b h F P P u u a u .0. o u u a u .0. o JUCIJUILh JOCIJUILb 108 fl v 1 — L ”fl . F Y _11, L v 1.11.; |_ A . a . . u I u no JUCIJUOLt d d u d . _ 1 «11.41314144111114141—1111411:91—11 A 4 L .1 F1— ...up pl. plLrL b b L h h b r p b rrh - h1—1. ..o ‘ TL7E.NormSizc 1.17.1. . . . 7.-JI.1]|41~JJ1311414J1_1.11.«J-J j m L _H L v L f T 1 I _.11 1 _ _ _ T _ _ 1 Y _ # _.i! 4 - 1 71—1Pu1—1r——b 51- h — h P b h — b P h b — b b P P1P F. p h blr « u a a u u o JUCIDUILh lo. TLBA.NormSizc ND 1-1]1.. . .dn..-.-11-.1._- .JI.1..--_11I.1.1.-.._ ..-. -. _1 1._- .1. . . _.-. . 1111—11.. ..1 4.14141 . . ... .. ...; T 1 . 1 . r V Y A . . FA _- .----- . 1........w......11.w. . TLBB.NormSiz¢ TL8C.NormSizc W1— 1 1 . r 111--. . . 1 . _ .1111 U , .11. T L I r 1 —» ..p-rL1r1.—I1FIF1_1IPIL1»1P1_.__-pnn—zbluerhlr L p r»: P —L p h p — p p b p — PL » p p 0 o o O O u u a u ..o. o u a ‘ JUCIJUIL$ JUCIJUILk froqucncg frcqucncg H0 1 1 fl 1 T a: 1 1 1 _. g 1 * a | . L I 1 1 1‘11 .—. ‘1 1g 1 1 A 1 1 -l.1 0.. L. l.. 3.. TLBD.NormSizn I 14—1—1 . i _ ,._ I l 4_l_l #Jg _l__l--l.l_ TL8E.NormSizc I.'— 4 ; , 1 r 1 _ . 1 111 r1 7] - 1H . q d q q d d 1 d d — q d 1 4 — 1 d 4 d — ll.1llll ‘lll, _ JOCIJUIL‘ . I p P b b b1b b.11—1LI—rl r. ; L A A 1.. TL8F.NarmSizn T 71—14114 4.. -.- —...- a ..< .- 1—141J14141dulq141J1411dJ11c1diJ 1—1 r17 .11—1rtblLI W F--- ..--.L I 4 . r |L1~11—1—L1.>1Ir11—1 —1h1h1PL1—LL- .F1—..—.- . a u .o. JUCIJUOLt L k A TL80.NormSizc H2 .._.—[411% TLSA.NormSiza JDCUJUULh |y_yl11. _ ‘1 _‘. 1‘1“41_J>J|11‘_ ~1AI:.1_;< w—l 4|.l. J A141 [—1 EEK—...P—b» a u.—.F»._..-.h JUCUJUIL; i TLSB.NormSizc H3 JUCIJUIgh 1—---...... _J.~...l.1_ .....-Ju. .fl...q!...1Jl_€1-4 . _._ A... . .-_l 1 L T LA 1 _-L ‘ .l llvlll 1 :!LL T — L _ l A .11 A il — I. r A V 4 .1. j I _ P , fl A F A I _ 1 r _ 4 L r r1 4 f 1 — — D h b h b Lr h b!_ b h b P — h P b h F b r h b — b b h F— a a u u ... .. . ..O TLSC.NormSizc 1'_ Jlfll n: ¢ - —.- - 'acl—l ..I—u- dildl «IIAIJ ln'qlldlad'qlq-.4" .. -, —|u g rLLL — h p p p — h b no» — bk b - JUCIJUILb C a. TL90.NormSizo frequencu fr-qu-ncy H4 u ' _W '_ T r T‘ — ' t _ [1W ‘ IIi —. .m‘9 ah -‘ - TL10A.HarmSi¥e . ' r 3 i E i -_ i ; 3 E h 3 il l ,g “ TL103.NormSizc H5 ll11].JIJJIJI .nIJJJIJlqul 1114i nl—ldIl-II-Iy-VI—ol 1 . TL10C.NormSiza _ _ _ ._ ..F_Lh._ prL u u n u n u - JOCOJUULh r I!—,l+p._>...—-...—..-.—.P>F— u u a u u a JUCIJUUL; I—lul<.1‘4l—. ‘L_!~'—A.— 1 . - . — < _ . d d u u - _ _ _foL>—»FLp—-.p._-p.—....— TL11E.NarmSizc u u a u u o JUCIJUILL 118 I JlldJlldl Jt-—l.nld...ldllq|-—|4Jcldl_—l _.l.‘ . .lA-lql—lnj.-sq.l--'—IJ i L 'A — h b p b — P h h L — P p n h P b P h p — b b 5|..th JUCIJUIgh 4.. 8.. TL11F.NormSizc Jollil , _ . I _ _ _ q ._9 q 14‘ - .-..‘uflA r A f A _ A f _ A _ F . _ . . _ L _ p . L m m u u a . JUCUJUILL 3‘ u '1 TL118.NarmSizn H9 T_ JUCflJUflLh TL129.NormSizl v i Id}... _ . _ ... _ _I—‘fi1.-|-5- — . - d.4| d J - _r_ — TL138.NarmSizo JUCIJUILh no r. 41JJ4_ _1_ — _ —!_|-|4—JI—‘-!_I._ - _ —J‘1_Jl_.-..¢ _._} LII JUCIDUOLh MS490108.N0rmSizn I_‘-:‘_lq _ —‘ .-.I—v<.‘_-..._ JUEIJUIL; MS4901DS.NormShort frnquoncg frcquoncu O. I. II I. 121 h_I I i I T l I I ' I I 1.] P r I I . _1 ... b _I " I . I— .1 _ 7 I- _ [—1 CI. » -i _ ._.. _1' - r—d I d: ’ I——: I 7 _ I I I I—I_ : . I I I 1 . a I": Fla. 5 I— . _t A _- I ' . . A 1 L4 . 4 .¥ I 1 A1 . 4 . . LA I. 1 I o 0.0 3 LI a_ 3.0 a MS4904DS.NormSizc T I T L _._ l: - 1 i- r— J I' ‘. L _. — C 4. i- —I I—1 3 I LII— * L 1 7 I I I :——I _ 1 l A - . 4 l , . A A l 1 . '0. 0.. I-. Co. 3.. "$89303.Norm3i2l n2 Y. v If‘rv f1 Y #7 Y ' Y Y Y jfifi Y Y —h b PI» — FLIP rh h p p P — hi-ILILII— tItvlh-IrrbthI—I filI—o¢..-.__.-——_,.‘.—-_._._._l.—a-__..._ u a u JUCIJUILL L l A L A A 4' I1 M8894DS.NormSizc I ' V T T V 1 V I Y— T 'Y' T I 7 v T J.:d..—.JI .,— u q a .._ -oqI-I..l— I‘ll-.-.L.I_l—JJI¢.I— _ -,_ . _ m H _l . F47? LuthL'th.IEL—pbbhbthP—bbbb—hbPb? A L44 ‘ . L JUCIJUULh ... M3897DS.NormSizc fraquencg fraquancu n3 1 M3891203.NormSizc IILI Us l M88914D$.Norm812l U4 jInIJ‘JII-II— I14lJI_ I-—IJI— -.fi .1. IquITflI-Id JII—I _I.—II—IJ T u u a u mucuawflLm . I. rIpIPI_ . —I_ ILILI P - —LIL.|PI—I —I,._L.Ir|FIIhvo1—I._ILIILIII—II I; ‘O. KHSITSAT.NormSize T 7 T ffi—j‘ v Ifllq...l-n “4-1—3: _IJII- —Iq« d J- _..-- I. q — q ~II4II—J II. 1 F. - . g fl r _ H mm 4 r L, A , I LIL, IhIh IA—III—f..- I!—II—.LLI- ~I..— IrLILouIPI LIIrLIIIC u u u . . . EUCUDUILh 0.? KMJNSMELoNDrmSiZI U5 T .II—JI‘._ _I—I—II-I-I-. _. WIJI- _ — _..I1I-I< I—I—u- V_ — _ LA+A' KMSSUKCL.NormSize FLILI» I _.lrIrIpIpLIrlle Lirg u u u o JUCUJUNLt JUCUJUOLh BDSGM.NormSiz¢ n6 BDBTS.NarmSiz¢ JUCOJUmLL —| -I. — I4 : —I..II—IVJIAII—I-I—IIJII—IIJII-I,_ .fig _w 41 A I 1 I I I . I t I I I I ‘_ L BDST32.NormSizn DUEmJUULk BIBLIOGRAPHY Beaumont, C., Quinlan, G., and Hamilton, 1., 1988 Orogeny and Stratigraphy: Numerical models of the Paleozoic in the eastern interior of North America. Tectonics, 7 (3), 389-416. Breiman, Leo Statistigg: With a Viaw Toward Applications. Houghton Mifflin Co., Boston, MA, 1973. Brown, George D. Jr., and Lineback, Jerry A., 1966 Lithostratigraphy of Cincinnatian Series (upper Ordovician) in southeastern Indiana. American Association of Petroleum Geologists Bulletin, 50(5) 1018-1032. Bury, Karl V. ' ' M 1 in A 1i i . John Wiley & Sons, New York, 1975. Carlson, W.D., 1989 The significance of intergranular diffusion to the mechanisms and kinetics of porphy- roblast crystallization. Contributions to Mineralogy and Petrology, 103 (1) pp. 1-24. Cashman, K.V., and Marsh, B.D., 1988 Crystal Size Distribution (CSD) in Rocks and the Kinetics and Dynamics of Crystallization II: Makaopuhi lava lake. Contributions to Mineralogy and Petrology, 99, 292-305. Conover, W.J. Wm. John H. Wiley & Sons, Inc., New York, 1971. Cumings, ER, 1908 The stratigraphy and paleontology of the Cincinnati Series of Indiana. Indiana Department of Geology and Natural Resources Annual Report, 32, 607-1188. Davis, John C. W. 2nd edition, John Wiley & Sons, Inc., New York, 1986. 127 128 Davis, R.A., 1986 Cincinnati Region: Ordovician stratigraphy near the southwest comer of Ohio. In '01» 1 a1 0 i fAmri . n nn' F1] -10: - o rn ‘ tin. Geological Society of America, 1986. Folk, Robert L. 1 f im R k . Hemphil Publishing Co., Austin, Texas, 1980. Friedman, G.M., 1965 Terminology of crystallization textures and fabrics in sedimentary rocks. Journal of Sedimentary Petrology, 35, 643-655. Fridy, J .M., Marthinsen, K., Rouns, T.N., Lippert, K.B., Nes, 13., and Richmond, 0., Characterization of 3-D particle distributions and effects on recrystallization studied by computer simulation. in Proc. of ICAA3, Tronheim, Norway, June 22-26, 1992. Frost, H.J., and Thompson, C.V., 1987 The effect of nucleation conditions on the topology and geometry of two-dimensional grain structures. Acta Metallurgica, 35 (2), pp. 529-540 Gregg, J .M., and Gerdemann, P.E. Sedimentary facies, diagenesis, and ore distribution in the Bonneterre Formation (Cambrian), southeast Missouri. In: Fi 1d i r ri f 0. ‘fith' 0-" .fi‘rau ‘Aln!’ 010' 14040 |Jl‘010' Eds. Gregg, J .M., Palmer, J.M. and Kurtz, V.E., 1989, 43-55. Gregg, J .M., and Howard, S., 1990 Crystallographic and mineralogic studies of Recent, peritidal dolomites, Ambergris Cay, Belize. (Abstract). Geological Society of America Annual Meetings, 22, 179. Gregg, J .M., and Shelton, KL, 1990 Dolomitization and dolomite neomorphism in the back reef facies of the Bonneterre and Davis Formations (Cambrian), southeastern Missouri. Journal of Sedimentary Petrology, 60, 539-562. Gregg, J.M., and Sibley, DE, 1984 Epigenetic dolomitization and the origin of xenotopic dolomite texture. Journal of Sedimentary Petrology, 54, 908-934. Groeneveld, Richard A., 1991 An influence function approach to describing the skewness of a distribution. The American Statistician, 45 (2), 97-102. Hartmann, Daniel, 1988 The Goodness-of-fit to Ideal Gauss and Rosin Distributions: A new grain-size para- meter. Discussion. Journal of Sedimentary Petrology, 58, 5, 913-917. 129 Hatfield, Craig Bond, 1968 Stratigraphy and paleoecology of the Saluda Formation (Cincinnatian) in Indiana, Ohio, and Kentucky. Geological Society of America, Special Paper Number 95. Holland, SM, 1993 Sequence Stratigraphy of a Carbonate-Clastic Ramp: The Cincinnatian Series (Upper Ordovician) in its type area. Geological Society of America Bulletin, 105, 306-322. Keith, B., 1985 Facies diagenesis and the upper contact of the Trenton Limestone of northern Indiana. In: wovician and Silurian Rogkg 9f me Mighigan Baain. Cercone, K.R. and Judai, J .M. (Eds), Michigan Basin Geological Society Special Publication No. 4, pp. 15-32. Kretz, R., 1974 Some models for the rate of crystallization of garnet in metamorphic rocks. Lithos, 7, pp. 123-131. Krumbein, W.C., 1935 Thin-section mechanical analysis of indurated sediments. Journal of Geology, 43, 482-496. Lorenz, B., 1989 Simulation of grain-size distrubutions in nucleation and growth processes. Acta Metalurgica, 37 (10), pp. 2689-2692. Larikov, L.N., Karpovich, V.V., and Dneprenko, V.N., 1989 Computer analysis of regularities of nucleation and crystal growth in a solid. Cryst. Res. Technol., 24(6), 579-583. Mahin, K.W., Hanson, K., and Morris, J .W., Jr. The computer simulation of homogeneous nucleation and growth processes. In Cgmputar Simglatign far Matgrials Applicatigna, 1976, (ed., Arsenault, R., Simmons, J., and Beeler, J .), National Bureau of Standards, Gaithersburg. Mahin, K.W., Hanson, K., and Morris, J .W., Jr., 1980 Comparative analysis of the cellular and J ohnson-Mehl microstructures through com- puter simulation. Acta Metallurgica, 28, 443-453. Marsh, B.D., 1988 Crystal Size Distribution (CSD) in Rocks and the Kinetics and Dynamics of Crystallization 1: Theory. Contributions to Mineralogy and Petrology, 99, 277-291. Marthinsen, K., Lohne, 0., and Nes, E., 1989 The development of recrystallization microstructures studied experimentally and by computer simulation. Acta Metalurgica, 37 (1), 135-145. 130 Miller, Michael, 1988 Dolomitization and Porosity Evolotion. PhD. Disertation, Michigan State University, East Lansing, Michigan. Moore, P.G. Prinoiolos of Sgtiatical Tochniguea, Second Edition, pp. 164-199. Cambridge University Press, 1969. Neave, HR, and Worthington, P.L. Distg'ootion-Froo Toots. Unwin Hyman, London, 1988. Nordeng, S. and Sibley, DE, 1990 Diffusion Limited Growth of Dolomite, Saluda Formation, (Ordovician, Indiana). (Abstract). Geological Society of America Annual Meeting, 22, A178. Pingitore, N.E., Jr., 1982 The Role of Diffusion During Carbonate Diagenesis. Journal of Sedimentary Petrology, 52, 27-40. Russ, J .C. Size distributions. In W, Chapter 4, pp. 53-72, Plenum Press, 1986. Saetre, T.O., Hunderi, 0., and Nes, E., 1985 Computer Simulation of Primary Recrystallization Microstructures: The effects of nucleation and growth kinetics. Acta Metallurgica, 34(6), 981-987. Sibley, DR, 1990 Unstable to stable transformations during dolomitization. Journal of Geology, 98, 739-748. Sibley, DE, and Gregg, J .M., 1987 Classification of dolomite rock textures. Journal of Sedimentary Petrology, 57, 967- 975. Siegel, Sydney WW McGraw Hill. 1956. Taylor, T.R., and Sibley, DE, 1986 Petrographic and geochemical characteristics of dolomite types and the origin of fer- roan dolomite in the Trenton Formation, Ordovician, Michigan Basin, USA. Sedimentology, 33, 61-66. 131 Tweed, Cherry J., Hanson, Niels, and Ralph, Brian, 1983 Grain growth in samples of aluminum containing alumina particles. Metallugical Transactions A, 14A, 2235-2243. Vaz, M.Fatima, and Fortes, M.A., 1988 Grain Size Distribution: The Lognorrnal and Gamma Distribution Functions. Scripta METALLURGICA, 22, 35-40. Vernon, R., Reactions in microstructure development. In Metamorphic Processes, Halstead Press, John Wiley & Sons, N.Y., 1975 Walters, Sylvia J., 1988 Th w-imn 010? .no_ ....lm: Ev°t n ofa‘ ...10 F011.on n‘l‘ rdovi ian 0 Hi hwa 421 eff r onC nt Indiana. unpublished Masters thesis, University of Cincinnati, Cincinnati, Ohio. Wilson, J .L., and Sengupta, A., 1985 The Trenton Formation in the Michigan Basin and environs: Pertinent questions about its stratigraphy and diagenesis. In Cercone, K. R. and Budai, J. M. (Eds. ), Ordovician and Silurian rocks of the Michigan Basin. MiohigaoB gin leoo ogic cg Sooi roty Specr cial Pluoi roation No.4 ,.pp 1- l3.