Geology of the Squaw Peak porphyry copper- molybdenum deposit, Yavapai County, Arizona Item Type text; Thesis-Reproduction (electronic); maps Authors Roe, Robert Ralph, 1950- 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 25/09/2021 21:25:04 Link to Item http://hdl.handle.net/10150/555079 GEOLOGY OF THE SQUAW PEAK PORPHYRY COPPER-MOLYBDENUM DEPOSIT, YAVAPAI COUNTY, ARIZONA by Robert Ralph Roe A Thesis Submitted to the Faculty of the DEPARTMENT OF GEOSCIENCES In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE In the Graduate College THE UNIVERSITY OF ARIZONA 19 7 6 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of re­ quirements 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. B rief 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 m aterial is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: ACKNOWLEDGMENTS I am indebted to all of the present and form er members of the exploration staff of Essex International, In c., whose assistance made possible this study. I would personally like to thank form er Essex geologists J. Kenneth Jones and Dennis Temple, and draftsman Adeline Cross, who offered most helpful criticisms during the course x of my work. I would particularly like to extend thanks to Paul I. Eimon and E. Grover Heinrichs, who made this investigation possible through their confidence and patience. I am grateful to my advisor, Dr. John M. Guilbert, who gave me much assistance and personal attention in the face of his very demanding schedule. I would also like to thank Dr. S .R . Titley and Dr. George H. Davis, who constructively criticized the final stages of this report. I am grateful to many fellow graduate students at The University of Arizona for their advice. ii i TABLE OF CONTENTS Page L IS T O F IL L U S T R A T IO N S ................................................................... v i A B S T R A C T ..................................................................................................... v iii 1 . IN T R O D U C T IO N .......................................................................................... 1 P re vio u s W o r k ................................................................................... 2 M ethods o f In vestig ation ............................................................. 3 Location and G eography ............................................................. 5 E x p lo ra tio n H is to ry ....................................................................... 7 2. GEOLOGIC SETTING .............. 13 General Geology of the Squaw Peak Area .............. 16 3 . L IT H O L O G Y .................................................................................................... 19 P re c a m b ria n Rocks ....................................................................... 19 Ash Creek (?) Metamorphosed V o lc a n ic Rocks ........................................................ 19 P re c a m b ria n G ra n o d io rite ............................. 23 Paleozoic Rocks .......................... 27 Cambrian Tapeats Sandstone ................... 27 Devonian M a rtin Lim estone .......................................... 30 L a ra m id e (?) R o c k s .........................: .............................................. 32 Squaw P eak In tru sio n ...................................................... 32 Q u a rtz M onzonite D ikes ................................................. 35 Pebble Dike ........................................................................... 36 Latite Porphyry D ikes .......... ........................................... 36 C enozoic Rocks ................................................................................ 38 Tertiary Hickey Basalt ................................................... 38 V e rd e F o r m a tio n .................................................................. 41 Andesitic and Basaltic Volcanic R o c k s ........................................................................... 42 Pleistocene (?) Rhyodacite ............................................ 44 Pleistocene (?) G ravels ................................................... 45 Quaternary River wash ................................................... 45 iv V TABLE OF CONTENTS— Continued Page 4 . S T R U C T U R E ................................................................................................... 46 P r e -L a ra m id e S tru c tu re ............................................................... 47 L a ra m id e S tru c tu re ......................................................................... 48 " A p litic S h a tte red Zo nes" ................. 48 G ra n itic S h e a r Z o n e s .............................................. 52 P o s t-L a ra m id e S tru c tu re ............................................................. 54 V e rd e F a u lt ................................................................................ 54 Structures Cutting the Squaw P eak In tru sio n ............................................................. 55 Shear Breccia and Shear Breccia Zones ...................................... 56 The Verde Fault Related to Regional Structure ................................................... 56 5. MINERALIZATION AND ALTERATION ......................................... 60 , Inner Zone Alteration and Mineralization ............................. 60 Outer Zone Alteration and Mineralization ........................... 76 6 . IN T E R P R E T A T IO N ..................................................................................... 80 Genesis of the Squaw Peak Deposit ......................................... 83 Comparison to Porphyry Deposits of the Prescott A rea ........................................................................... 87 7. EXPLORATION POTENTIAL ...................... ...................................... 91 8 . C O N C L U S IO N S ............................................................................................ 96 Geologic History ................................................................................ 96 R E F E R E N C E S ............................................................................................... 99 LIST OF ILLUSTRATIONS Figure Page 1 . Geologic Map of the Squaw Peak A re a ............................. in pocket 2. Geologic Map of the Squaw Peak P o rp h y ry C opper D eposit ............................................ in pocket 3. Geologic Sections of the Squaw Peak A re a .................... in pocket 4. Alteration and Mineralization Zoning of the Squaw Peak Deposit ............................. ................ in pocket 5. Location Map of the Squaw Peak Area (1 : 2 5 0 ,0 0 0 ) ........................................................................................ 6 6 . Squaw P eak A re a ..................................................................................... 8 7. Plan of Squaw Peak Mine Main Tunnel Level ........................... 10 8. Photomicrograph of Ash Creek (?) Meta­ m orphosed V o lc a n ic R o c k ........................................................ 22 9. Relative Compositions of 45 Specimens of Precambrian Granodiorite from, Thin- Saction Petrographic and Binocular Microscope Estimates of Rough and Saw ed S u r fa c e s ........................ 24 10. Exposure of Pebble Dike in Road C ut ........................................... 37 11 . P ho tom icro grap h o f H ickey B a s a lt................................................... 40 1 2 . V e rd e F a u lt .................................................................................... 43 13. Poles to Mineralized Fracture Planes and Veins at the Squaw Peak Deposit ....................................... 49 14. Outcrop in Aplitic Shattered Zone ................................................... 50 15. An Exposure of a Bleached Granitic Shear Zone South of the Squaw Peak Intrusion ......................... 53 v i v ii LIST OF ILLUSTRATIONS— Continued Figure Page 16. Granodiorite Exposure at Contact with Granitic Shear Zone ................................................................. 53 1 7 . S h e a r B re c c ia Zone ................................................................................ 57 18. The Verde Fault in its Regional Tectonic S e ttin g ............................................................................................... 58 19. High Fracture Density Zone in Precambrian G ra n o d io rite ................................................................................... 61 2 0 . C opper S o il G e o c h e m is tr y .................................... 64 2 1 . M olybdenum S o il G eo ch