Geology and mineralization associated with the early proterozoic alder group, the Sunflower Mining District, Maricopa and Gila Counties, Arizona Item Type text; Thesis-Reproduction (electronic); maps Authors Orr, Richard Leigh, 1959- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 03/10/2021 23:13:42 Link to Item http://hdl.handle.net/10150/558128 > GEOLOGY AND MINERALIZATION ASSOCIATED WITH THE EARLY PROTEROZOIC ALDER GROUP, THE SUNFLOWER MINING DISTRICT, MARICOPA AND GILA COUNTIES, ARIZONA. by Richard Leigh Orr A Thesis Submitted to the Faculty of the DEPARTMENT OF GEOSCIENCES in Partial Fulfillment of the Requirements for the Degree of MASTERS OF SCIENCE In the Graduate College THE UNIVERSITY OF ARIZONA 1 9 9 0 3 UJ CL U 2 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under the rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgement of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgement the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: APPROVAL BY THESIS DIRECTORS This thesis has been approved on the date shown below: ACKNOWLEDGEMENTS I wish to express my deep appreciation to Dr. Clay Conway of the U.S. Geological Survey who brought the study area and some of the poignant problems I have addressed to my attention. Dr. Conway's direction of Survey support of base maps, areal photos, and logistics have been invaluable in the field. Dr. Chris Eastoe, as my thesis director, has provided continuous guidance, encouragement and moral support. I am indebted to Dr. Eastoe for his assistance in obtaining financial support, direction in collecting my stable isotope data, and innumerable other aspects of this study. Dr. Eastoe has been the principal directing influence on the out come of this research, for this I am deeply grateful. I thank Dr. Ed Bloomstein of Santa Fe Pacific Mining, Inc. for his direction of financial support of whole rock analyses and thin sections, without which this study could not have been possible. James Duncan and American International Mining and Milling Corp. have been most gracious in allowing me the use of a trailer at their millsite which made the weeks in the field more tolerable and productive. Mundo Mesa and his family made camp life most enjoyable. David Melander of Chevron Minerals Research provided reduced carbon analyses and additional carbon isotope data of black shales for which I express my gratitude. I extend special thanks to Wes Bilodeau, Tom Teska, Lisa Warneke, Adonna Flemming, and Mae Gustin for their generous assistance in laboratory aspects of this project. Other colleagues and friends have contributed in discussions, field excursions, and debate to the shaping and outcome of this research. Thanks to all. I express my gratitude to all members of my thesis committee, Drs. Chris Eastoe, Paul Damon and Joaquin Ruiz, for all their confidence and patience in this pursuit. Finally, I send my love to my parents, Kenneth and Hildur Orr, for it is from them that I have learned to pursue my goals and aspirations through hard work, ethics, and perseverance. 4 TABLE OF CONTENTS LIST OF ILLUSTRATIONS . ................................ 7 LIST OF T A B L E S ....................................... 10 ABSTRACT ............................................. 11 INTRODUCTION ......................................... 12 Location, Physiography, Climate, and Culture . 12 Purpose and Methods of S t u d y ..................... 16 PREVIOUS W O R K ......................................... 18 Regional Geology .............. 18 Precambrian Geology ................ 18 Stratigraphy ................................... 24 Intrusive Rocks ............................... 26 S t r u c t u r e ..................................... 29 Economic Geology and Mineralization ............ 32 Deposit Types and District Distribution .... 32 Metallogenic Settings ......................... 32 Mineral Production ............................. 33 LITHOLOGIC UNITS ..................................... 35 Introduction ..................................... 35 Alder G r o u p ..................................... 35 Squaw Flat Formation........................... 38 West Fork Formation .................. 39 Horse Camp Formation........................... 39 Cornucopia Formation ..................... 41 East Fork Formation ........................... 44 Oneida Formation ............................... 45 Telephone Canyon Formation ..................... 46 The Alder Depositional Basin ..................... 49 Haigler Group ................................... 50 Red Rock Rhyolite ............ 50 Mount Peeley Ignimbrites..................... 51 Intrusive Lithologies ........................... 51 Pine Mountain Porphyry ......................... 51 Rhyolite Dikes ................................. 52 Diorite Dikes ..................... ...... 53 Gabbroic Intrusion ............................. 53 Andesite Dikes ................................. 54 Cenozoic Cover ................................... 54 Tertiary Volcanic Rocks . ............ .... 54 G r a v e l s ............ 54 5 STRUCTURE............................................... 55 District Scale Structures ................. 55 The Red Rock Syncline ...................... 55 Structures of the Jasper-Dolomite Exhalite .... 59 Olistostromes, Tectonic Breccias and Shear Zones . 62 HYDROTHERMAL DEPOSITS.............................. 64 The Cornucopia Volcano-Exhalative System .......... 64 Character and Distribution ...................... 64 Petrology and Mineralogy ......................... 67 Polymetallic Deposits . ......................... 70 Distribution, Mode and Occurrence .............. 70 Ore Petrology, Mineralogy and Paragenesis . 72 Ore Controls..................................... 77 Geochemistry and Metal Ratios .......... 79 Ore G e n e s i s ..................................... 83 Mercury Deposits ................................... 85 Distribution and Mode of Occurrence ............ 85 Ore Petrology and Mineralogy.................... 86 Paragenesis ..................................... 88 Alteration....................................... 91 Ore Controls..................................... 91 Ore G e n e s i s ..................................... 93 Quartz-Tourmaline Veins ........................... 96 WHOLE ROCK GEOCHEMISTRY................................. 98 Purpose and M e t h o d s ............................... 98 Major Element Chemistry ......................... 100 Mass B a l ance........................................ 105 Trace Elements and Tectonic Setting ............ 107 GEOCHEMISTRY OF VEIN AND ALTERATION M I N E R A L S ........... Ill Purpose and M e t h o d s ............................... Ill Carbonate Chemistry ............................. Ill Sulfide and Sulfosalt Chemistries ................ 114 Tourmaline Chemistry ............................. 119 STABLE ISOTOPE GEOCHEMISTRY ............................ 123 Carbon and Oxygen Isotopes ........................ 123 Purpose and M e t h o d s ............................. 123 R e s u l t s .......................................... 124 Sedimentary Limestones ......................... 127 Altered Volcanics and Exhalative Dolomite . 128 Temperature Constraints ........................ 131 Isotopic Composition of Proterozoic Oceans . 133 Light Carbon and Oxygen Reservoirs .............. 133 Vein Carbonate....................................134 Reduced Carbon in Black Shales .................. 134 6 Sulfur Isotopes ................................. 135 Purpose and M e t h o d s ............................. 135 Polymetallic Deposits ......................... 139 Mercury Deposits ............................... 139 D I S C U S S I O N .............................................. 140 APPENDIX A: SAMPLE DESCRIPTIONS ....................... 142 REFERENCES CITED ..................................... 147 7 LIST OF ILLUSTRATIONS Figure Page 1. Location and geographic setting of the Sunflower mining district ........... 13 2. Study area reference map with key locations ... 14 3. Regional Precambrian geology and location map of previous studies ......................... 20 4. Distribution of Precambrian exposures,physio­ graphic provinces, and the two province boundary of the Older Precambrian .......... 22 5. Regional structure of the Mazatzal Mountains .. 26 6. Stratigraphic column of the Early Proterozoic Alder and Haigler groups in the central Mazatzal Mountains .......................... 37 7. Photograph of pillow basalts of the middle member of the Cornucopia Formation in McFarland canyon ............................ 43 8. Photograph of the Zebra shale bed of the Cornucopia Formation ........................ 43 9. Photograph of the basal conglomerate of the Oneida