Economic geology of the Alamos Mining District, Sonora, Mexico Item Type text; Thesis-Reproduction (electronic); maps Authors Vazquez Perez, Adalberto, 1944- 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 05/10/2021 10:06:43 Link to Item http://hdl.handle.net/10150/566636 ECONOMIC GEOLOGY OF THE ALAMOS MINING DISTRICT, SONORA, MEXICO by Adalberto Vazquez Perez A Thesis Submitted to the Faculty of the DEPARTMENT OF MINING AND GEOLOGICAL ENGINEERING In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE WITH A MAJOR IN GEOLOGICAL ENGINEERING In the Graduate College THE UNIVERSITY OF ARIZONA 19 7 5 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of require­ ments for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment 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 judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the a u th o r. SIGNED: APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: / 77r WILLIAM C. PETERS Date Professor of Mining and Geological Engineering Con todo carino a Pupis B e tito O sca rito por sus sacrificios ACKNOWLEDGMENTS I am deeply indebted to individuals both on and off the campus of The University of Arizona for their support. On campus, I wish to express my deep appreciation to Dr. William C. Peters, my major professor and advisor, to Dr. De Verle P. Harris and to Mr. Edward Jucevic for their guidance and encouragement. Off campus, special gratitude is due to Ing. Guillermo P. Salas, General Director, and to Ing. Ruben Pesquera, Exploration Manager, of the Nonrenewable Natural Resources Council, as well as the National Council of Science and Technology, of Mexico for their financial support during my stay in Tucson. i v TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS......................................................................................................v i i LIST OF TABLES........................................... % ABSTRACT . ..................................................... .... ...................................... x i 1. INTRODUCTION .............................................................................................................. 1 rH <NJ <M (N bO K) VO Purpose and Scope of Study Methods of Study .... Preliminary Reconnaissance of Prospects ............................. Photogeologic Interpretation and Field Check of Geologic Units and Structures ................................. Underground Mapping and Sampling of Prospects . L ocation and A ccess ........................................................................................... H isto r y and P ast P roduction ........................................................................ 2. REGIONAL GEOLOGY............................ 9 Geomorphology . ..................................................................................................... 9 S ie r r a Madre O ccid en ta l P rovince ............................................... 9 Sonoran D esert P rovin ce .......................................................... 13 C o a sta l P la in o f S in a lo a P rovince ............................................ 13 S t r a t i g r a p h y ...................................... ................................................ 14 P r e c a m b r ia n ................................................................................................ 15 P a l e o z o i c ............................................................................ 17 M e s o z o ic .............................................................. 20 C e n o z o ic .......................................................................................................... 24 S tru ctu re and S tru ctu ra l H i s t o r y ..................................................... 26 Sonoran Desert Province .............................................................. 27 S ie r r a Madre O ccid en ta l P rovince ............................................... 28 3. ALAMOS D IS T R IC T .............................................................................................................. 31 G eneral G eology ..................................................................................................... 31 • Geomorphology ............................................................................................ 31 S tra tig ra p h y ................................................................................................ 33 S t r u c t u r e ..................................................................................................... 41 V v i TABLE OF CONTENTS—Continued Page Economic G eology ........................................................................ ..... 46 Ore C ontrol .................................................................. 46 Ore Mineralogy 49 Mineral Paragenesis and Zoning .................................. .... 50 Ore G e n e s i s ................................................................................................ 53 Description of Mines ............................................................................. 57 Economic A s p e c t s ............................................................................ 88 Grade o f O r e ................................................................................................ 88 Ore R e s e r v e s ...................................... 89 E xp loration P r o g r a m .................................................... 91 Economic C on sid era tio n s ................................................................... 93 4 . STATISTICAL A SP E C T S.................................................... 99 In tro d u ctio n .......................................................................................................... 99 Model and Methodology Employed ..... ............................................... 100 M u ltip le R egression A n a ly sis ...................................................................... 104 C onceptual Framework ............................................................................ 104 R e su lts o f A n a ly sis ............................................................................. 109 Trend Surface A n a ly sis .......................................... 113 C onceptual Framework ............................................................................. 113 Results of A nalysis ............................ 116 5 . CONCLUSIONS AND RECOMMENDATIONS ..............................................................................123 APPENDIX A — ECONOMIC CONSIDERATIONS FOR THE PROSPECTS IN THE ALAMOS MINING DISTRICT EXPLORATION PROGRAM, 1973-75 .................... 128 APPENDIX B — STATISTICAL CALCULATIONS FOR THE ALAMOS MINING DISTRICT EXPLORATION PROGRAM, 1973-75 ........................................................ 141 LIST OF REFERENCES................................................................................................................165 LIST OF ILLUSTRATIONS F ig u re Page 1. Location Map of the Alamos Mining D istrict, Sonora, Mexico .............................................................................................................. 4 2. Central Part of the Alamos Mining District ............................. 5 3. Geomorphic Provinces in the State of Sonora, Mexico . 10 4. Panoramic View of the Tertiary Volcanic Rocks Within the Barranca Section of the Sierra Madre Occidental P rovin ce ......................................................................................................... 12 5. Geologic Map of the State of Sonora, Mexico ............................. In p ock et 6. Geologic Map of the Alamos D istrict, Sonora, Mexico . In p o ck et 7. Panoramic View o f th e S ie r r a de Alamos ....................................... 32 8. Exposure of the Barranca Formation (Upper Triassic-Lower J u r a s sic ) in th e P ied ras Verdes Area ....................................... 36 9. Ridge of Tertiary Rhyolitic Flows Dipping 25° to the E a s t ................................................................................................................... 42 10. Location of Precious-Metal Districts along the "Main Welt" S tru ctu re in th e S ie r r a Madre O ccid en ta l P rovin ce .................... .................................................................................. 45 11. Abundance of Base-Metal Sulfides Plotted Against Their H eigh t above Basement ........................................................................ 48 12. Paragenetic Sequence for the Alamos Mining District . 52 13. Section N 30° E Showing Changes in Mineralogy among Mines in the Sierra de Alamos, Alamos D istrict ............................. 54 14. Location and Grouping of Mines