Lehigh Preserve Institutional Repository The Petrological Evolution of Garnet-Rich Meta- Igneous Bodies in the Southeastern Adirondack Mountains, New York. Weakliem, John Herbert 1984 Find more at https://preserve.lib.lehigh.edu/ This document is brought to you for free and open access by Lehigh Preserve. It has been accepted for inclusion by an authorized administrator of Lehigh Preserve. For more information, please contact [email protected]. - The Petrological Evolution of Garnet-Rich Meta-Igneous Bodies in the Southeastern Adirondack Mountains, New York by John Herbert Weakliem A Thesis Presented to the Graduate Committee of Lehigh University in Candidacy for the Degree of Master of Science in Geology Lehigh University 198M ProQuest Number: EP76481 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest EP76481 Published by ProQuest LLC (2015). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 This thesis is accepted and approved in partial fulfillment of the requirements for the degree of Master of Science. date; Professor in Charge Chairman of Department ii Acknowledgements The writer would like to thank his committee chairman, Dr. Charles B. Solar, for introducing the writer to the.problem, and for his lengthly review and comments Upon the manuscript. The other members of the committee, Dr. Paul B_ Myers of Lehlgh University and Dr^ Philip R. Whitney of the New York State Geological Survey, reviewed and commented upon it. Dr. Terry L. Pavlis of Lehigh University offered advice and suggestions. The Barton Mines Corporation granted permission to carry out the studies upon their property, and assisted in logistics. Mr. Gordon Hersey, and indeed, all of the employees of the Barton Mines Corporation were of grea't assistance to the writer. Dr. F. Bentel and Mr. F. Gramlich both permitted the writer to study outcrops upon their property. Dr. Roger H. Hewins of Rutgers University instructed the writer on data acquisition on the electron microprobe. Finally, Mr. James Kerner of the Department of Metallurgy and Materials Science, Lehigh University taught the writer the intricacies of operating, the microprobe. I would also like to thank my parents, Mr. and Mrs. Herbert Weakliem, who made this possible. Financial aid in support of this project was provided by grants frdm the Barton Mines Corporation, the Sun Oil Corporation, the Department of Geological Sciences, Lehigh University, and a grant- in-aid of research by Sigma Xi, the Scientific Research Society. iii TABLE OF CONTENTS ABSTRACT , . 1 INTRODUCTION , ; .. 5 FIELD AND ANALYTICAL METHODS 6 REGIONAL GEOLOGY 11 PREVIOUS WORK 16 General Garnet-forming Reaction 16 Garnet-Forming Reactions, Gore Mountain metagabbro 20 Garnet-Forming Reactions, Ruby Mountain Anorthosite 22 RUBY MOUNTAIN METAGABBRO 24 a Introduction... 24 Field Relationships 24 Bulk Chemistry . 29 Mineralogy, Petrography, and Mineral Chemistry 34 General Statement 34 Plagioclase .' .. 34 Composition 40 Pyroxene 44 Clinopyroxene 44 composition . 46 Orthopyroxene 55 i composition 57 Hornblende 57 iv Table of Contents (continued) 0 Composition i% , 59 Garnet 63 Composition 65 Biotite ... .... 70 Met am orphic Reactions 71 Origin of the Ruby Mountain Metagabbro 74 Protollth '. 74 Metamorphic History 74 THE SPECULATOR METAGABBRO * 77 Introduction 77 Field Relations 77 Bulk Chemistry 82 Mineralogy, Petrography, and Mineral Chemistry..... 83 General Statement. 83 Plagioclase 83 Composition 89 Pyroxene 89 Clinopyroxene 92 composition '. 96 Orthopyroxene 96 composition • • • • 102 Hornblende ,, 104 Table of Contents (Continued) , Composition 107 Garnet . 109 Composition 112 Biotite 112 The Large-Garnet Zone ., 118 Metamorphic Reactions 120 Origin of the Speculator Metagabbro 123 Protolith 123 Metamorphic History 123 Origin of the Large-Garnet Zone 125 OLD HOOPER MINE 127 Field Relations 127 Mineralogy and Petrography.. •• 127 Garnet Chemistry 128 Type of Deposit 129 NORTH RIVER GARNET COMPANY MINE 133 Field Relationships 133 Mineralogy and Petrography 133 Garnet Chemistry... 137 Type of Deposit 1 37 COMPARISON OF GARNET CHEMISTRY FROM VARIOUS BODIES.. 140 General Statement 140 vi Table of Contents (Continued) Garnet-Forming Reactions... 140 Compositions of Garnets 141 CONDITIONS OF METAMORPHISM. ' 145 SUMMARY AND CONCLUSIONS 147 BIBLIOGRAPHY 150 APPENDICES 155 VITA 172 vii List of Tables 1 Microprobe Standards Used ' • - 9 2 Bulk Chemical Data, Ruby Mountain and Speculator - 30 Metagabbros 3 Modal Mineralogies, Ruby Mountain - 35 4 Microprobe Data for Ruby Mountain Plagioclase - 42 5 Microprobe Data for Ruby Mountain Pyroxene - 51 6 Microprobe Data for Ruby Mountain Hornblende - 60 7 Microprobe Data for Ruby Mountain Garnet - 68 8 Modal Mineralogies, Speculator - 84 9 Microprobe Data fdr Speculator Plagioclase - 90 10 Microprobe Data for Speculator Pyroxene and - 98 Hornblende 11 Microprobe Data for Speculator Garfiet -113 12 Microprobe Data for Garnet from Old Hooper Mine -131 and North River Mine 13 Compilation of Garnet Compositions From Meta-Igneous -143 Rocks in the Region viii List of Figures 1 Location map of the Thirteenth Lake and Indian Lake - 7 Quadrangles, New York 2 Index map showing location of bodies which were - 8 examined in this study 3 Geological map and cross section of Ruby Mountain -25, 26 4 Sample locations, Ruby Mountain metagabbro - 27 5 Photomicrograph of a biotite -inclusion within an - 37 antiperthitic plagioclase, Ruby Mountain metagabbro 6 Photomicrograph of matrix plagioclase, Ruby - 38 Mountain metagabbro 7 Photomicrograph of thin plagioclase rim between - 39 large garnet porphyroblasts and hornblende, Ruby Mountain metagabbro 8 Photomicrograph of potassium feldspar surrounded - 41 by vermicular clinopyroxene and plagioclase, Ruby Mountain metagabbro 9 Photomicrograph of twinned inequant diopsidic - 45 augite, Ruby Mountain metagabbro 10 Photomicrograph of a clinopyroxene containing - 47-_ hornblende lamellae and minute opaque inclusions, Ruby Mountain metagabbro 11 Photomicrograph of inequant clinopyroxene - 48 surrounded Dy smaller, more equant clino-and orthopyroxenes, Ruby Mountain metagabbro 12 Photomicrograph of a mafic foliation band from the - 49 reservoir mouth, Ruby Mountain metagabbro 13 Ternary plot of microprobe analyses of pyroxenes, - 50 Ruby Mountain metagabbro ■—-■* 14 Microcrystalline vein and spinel inclusions within - 56 an orthopyroxene, Ruby Mountain metagabbro ix List of Figures (Continued) « 15 Photomicrograph of xenoblastic garnet from mafic - 58 foliation band, Ruby Mountain metagabbro 16 Photomicrograph of xenoblastic garnet and biotite - 64 within plagioclase matrix, Ruby Mountain metagabbro 17 Representative zoning trends in garnet - 67 porphyroblasts, Ruby Mountain metagabbro 18 Schematic diagram of possible relationship of Ruby - 75 Mountain anorthosite and metagabbro to Thirteenth Lake dome 19 Geological map of the Speculator metagabbro - 78 20 Sample locations, Speculator metagabbro - 79 21 Photomicrograph of equant, granoblastic plagioclase - 86 matrix, Speculator metagabbro 22 Photomicrograph of embayed contacts between - 87 plagioclase and clinopyroxene, Speculator metagabbro 23 Photomicrograph of a highly embayed plagioclase - 88 grain from large-garnet zone near garnet porphyroblast, Speculator metagabbro 24 Photomicrograph of clinopyroxene from large-garnet - 93 zone near garnet porphyroblast, Speculator metagabbro 25 Photomicrograph of xenoblastic garnet associated - 94 with clinopyroxene, Speculator metagabbro 26 Photomicrograph of granoblastic aggregates of - 95 clinopyroxene defining the metamorphic foliation, Speculator metagabbro 27 Ternary plot of microprobe analyses of pyroxenes, - 97 Speculator metagabbro 28 Photomicrograph of hornblende and clinopyroxene - 103 defining the metamorphic foliation, Speculator metagabbro 29 Plot of Fe2+/(Fe2++ Mg) vs. 100Ca/(Fe2++ Mg + Ca) - 105 for orthopyroxenes, Speculator metagabbro x List of Figures (Continued) 30 Photomicrograph of hornblende grains partially - 106 rimming magnetite, Speculator metagabbro 31 Photomicrograph of potassium feldspar-hornblende - 108 symplectite surrounding garnet porphyroblast, large-garnet zone, Speculator metagabbro 32 Photomicrograph of xenoblastic garnet, Speculator - 111 metagabbro 33 Zoning trends in garnet porphyroblasts, Speculator - 116, 117 metagabbro 3^ Zoning trend in garnet porphyroblast, Old Hooper - 130 mine i 35 Photomicrograph of coronas of vermicular - 135 clinopyroxene+orthopyroxene+plagioclase+spiriel and garnet around hornblende, North River Garnet Company mine 36 Photomicrograph showing vermicular clinopyroxene - 136 +orthopyroxene+plagioclase+spinel symplectite around hornblende in more detail 37 Zoning trend in garnet porphyroblast from North - 138 River Garnet Company mine 38 Ternary plot of microprobe analyses of garnet in - 142 terms of Gr, Py, Al from bodies examined in this study, as well as the Ruby Mountain anorthosite and Gore Mountain metagabbro XI ABSTRACT This study was undertaken in order to compare and contrast some of the smaller