The Geology of the Canada Del Oro Headwaters, Santa Catalina Mountains, Arizona
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The geology of the Canada del Oro headwaters, Santa Catalina Mountains, Arizona Item Type Thesis-Reproduction (electronic); text Authors Suemnicht, Gene Arthur,1948- 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 01/10/2021 20:01:10 Link to Item http://hdl.handle.net/10150/191658 THE GEOLOGY OF THE CANADA DEL ORO HEADWATERS, SANTA CATALINA MOUNTAINS, ARIZONA by Gene Arthur Suemnicht 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 1977 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. 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 judg- ment the proposed use of the material is in the interests of scholar- ship. In all other instances, however, permission must be obtained from the author. -) SIGNED: - APPROVAL BY THESIS DIRECTOR This the is has been approved on the date shown below: '/AiL7/20. /1? -7 ( H. DAVIS Date Associate Professor of Geosciences ACKNOWLEDGMENTS E. J. McCullough, Jr. and J. S. Sumner critically reviewed this manuscript and I would like to thank them for their encouragement and counselling. Financial support for this study was provided in the form of a Research Assistantship through the Arizona Bureau of Mines. R. T. Moore administered the grant and aided me with whatever facilities the Bureau could offer. H. W. Peirce provided an ever present ear, stimu- lating questions, and some liberally applied motivation throughout the course of this study. I am deeply grateful to George H. Davis, my thesis advisor, for his criticism, stimulation, and openness throughout this work and my studies at The University of Arizona. Acknowledgment beyond thanks are due to several friends. R. T. Budden stimulated my interest in the area and then left it unmapped in his compilation, leaving me no out. C. W. Kiven provided unusual though interesting perspectives, Tom McGarvin literally worked his fingers to the bone, Bob Varga added concern where needed, and Joseph LaVoie cast a kind eye on my drafting work for the manuscript. Bruce and Cherri Wachter provided unique and sober assistance. This work is dedicated to Twinx, who gave me the gift of direction. TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS vi LIST OF TABLES ix ABSTRACT INTRODUCTION ROCKS 5 Precambrian Rocks 5 Intrusive Rocks 5 Sedimentary Rocks 10 Minor Precambrian Intrusive Rocks 12 Metamorphosed Paleozoic Rocks 14 Boisa Quartzite 14 Abrigo Formation 16 Martin Formation 16 Escabrosa Limestone 17 Phanerozoic Intrusive Rocks 18 Introduction 18 The Leatherwood Quartz Diorite 18 The Granodiorite Porphyry 23 The Catalina Granite 25 The Reef of Rock Granite 35 Minor Phanerozoic Intrusive Rocks 42 Leatherwood Quartz Diorite Dikes 42 Granodiorite Porphyry Dikes 43 Catalina Granite Dikes 43 Reef of Rock Granite Dikes 45 Rhyolite Porphyry Dikes 45 GEOLOGIC STRUCTURE 47 Structure of the Canada del Oro Headwaters 48 Internal Structures of the Plutons 49 Oracle Granite 49 Leatherwood Quartz Diorite 53 Granodiorite Porphyry 55 Catalina Granite 56 Reef of Rock Granite 58 Large-Scale Faults 61 Geeseman Fault 61 iv TABLE OF CONTENTS--Continued Page Slickenside Lineation 64 Cataclastic Deformation 67 Minor Folds 71 Analysis 77 Dynamic Analysis 83 Interpretation 85 Hartman-Homestake Fault 91 Limb Fault 93 Lightening Bolt Fault 93 Large-Scale Folds 94 Apache Group Syncline 94 Marble Peak Syncline 96 GEOLOGIC HISTORY AND INTERPRETATIONS 98 CONCLUSIONS 102 REFERENCES 105 LIST OF ILLUSTRATIONS Figure Page 1. Location of the Canada del Oro Headwaters Study Area 2 2. Geologic Map of the Canada del Oro Headwaters, Santa Catalina Mountains, Pima-Pinal Counties, Arizona in pocket 3. Q-A-P Diagram (after I.U.G.S., 1973) 7 4. Gneissic Oracle Granite Fabric 9 5. Fine-grained Inclusion in Catalina Granite 30 6. Porphyritic Inclusion in Catalina Granite 31 7. "Salt and Pepper Like" Inclusion in Catalina Granite • • • 32 8. Contact of the Catalina Granite and Oracle Granite, Northern Exposure 33 9. Contact of the Catalina Granite and Oracle Granite, Southern Exposure 33 10. Shear Zones in the Border Phase of the Catalina Granite 34 11. Catalina Granite Apophyses in the Leatherwood Quartz Diorite 36 12. Large Leatherwood Quartz Diorite Blocks in the Catalina Granite 37 13. Reef of Rock Ridge 38 14. Catalina Granite Block in Reef of Rock Granite 40 15. Contact of the Reef of Rock Granite and the Catalina Granite 41 16. Aphte Dikes in Catalina Granite 44 17. Local Exposure of Gneissic Oracle Granite . 50 vi vii LIST OF ILLUSTRATIONS--Continued Figure Page 18. Lower-hemisphere Equal-area Stereonet Plot of Poles to Foliation in the Oracle Granite 51 19. Lower-hemisphere Equal-area Stereonet Plot of Mineral Lineation in the Oracle Granite 52 20. Lower-hemisphere Equal-area Stereonet Plot of Poles to Joints in the Oracle Granite 54 21. Offset Inclusion in Catalina Granite Border Phase 57 22. Lower-hemisphere Equal-area Stereonet Plot of the Orientation of Elongate Inclusions in the Catalina Granite 59 23. Lower-hemisphere Equal-area Stereonet Plot of Poles to Joints in the Catalina Granite 60 24. Lower-hemisphere Equal-area Stereonet Plot of Poles to Joints in the Reef of Rock Granite 62 25. Mylonization Zone along a Subordinate Plane of Movement of the Geeseman Fault 65 26. Lower-hemisphere Equal-area Stereonet Plot of Slickenside Lineations along the Geeseman Fault . • • 66 27. Photomicrograph of Oracle Granite Deformed by the Geeseman Fault 68 28. Photomicrograph of Abrigo Formation(?) Deformed by the Geeseman Fault 70 29. Southeast-trending Folds in Abrigo Formation(?) Deformed by the Geeseman Fault 72 30. Lower-hemisphere Equal-area Stereonet Plot of Northeast and Southeast Fold Axes 74 31. Southeast-trending Folds in Abrigo Formation(?) Illustrating Irregular Fold Style 75 32. Northeast-trending Fold in Abrigo Formation(?) Deformed by the Geeseman Fault 76 viii LIST OF ILLUSTRATIONS--Continued Figure Page 33. Schematic Diagram of Foliation Development during Strike-slip Movement of the Geeseman Fault 78 34. Lower-hemisphere Equal-area Stereonet Plot of Southeast-trending Folds Showing "Best Fit" Circle for All Axes 79 35. Minor Reverse Slip Deformation in Pioneer Formation Metasedimentary Rocks along the Eastern Trace of the Geeseman Fault 81 36. Mississippian Escabrosa and Permian Naco Group Limestone Thrust over Pioneer Formation along the Eastern Trace of the Geeseman Fault 82 37. Lower-hemisphere Equal-area Stereonet Plot of Northeast-trending Folds Showing "Best Fit" Circle for All Axes 84 38. Principal Stress Orientations during Strike-slip Movement of the Geeseman Fault 86 39. Principal Stress Orientations during Dip-slip Movement of the Geeseman Fault 87 40. Schematic Diagram of the Movement History of the Geeseman Fault 90 41. Hartman-Homestake Fault 92 LIST OF TABLES Table Page 1. Modal Analyses (in Volume Percent) of Oracle Granite, Catalina Granite, and Reef of Rock Granite 8 2. Modal Analyses (in Volume Percent) of Diabase Dikes and Sills in the Younger Precambrian Apache Group and a Dacite Dike in the Oracle Granite 15 3. Modal Analyses (in Volume Percent) of Leatherwood Quartz Diorite and Normative Analyses (in Weight Percent) of Granodiorite Porphyry 20 ix ABSTRACT Geologic mapping, with an emphasis on structure, was carried out in the region of the headwaters of the Canada del Oro. Major intrusive rock types delineated in the study area include the Oracle Granite, Leatherwood quartz diorite, granodiorite porphyry, Catalina granite, and Reef of Rock granite. Sedimentary rock types mapped in the area include the Younger Precambrian Apache Group, Cambrian Boisa Quartzite and Abrigo Formation, Devonian Martin Formation, and the Mississippian Escabrosa Limestone. Large wavelength synclines deform the Apache Group sedimentary rocks in the north and metamorphosed Paleozoic sedimentary rocks of Marble Peak in the south. The northwest-trending Geeseman Fault cuts across Oracle Granite, Leatherwood quartz diorite, and Catalina and Reef of Rock granites. Structural analysis indicates a Cretaceous(?) compo- nent of sinistral strike-slip displacement and a Tertiary component of dip-slip displacement, south block down. The Older Precambrian Oracle Granite is the oldest rock in the area. Tectonic quiescence is marked by the deposition of the Younger Precambrian and Paleozoic sediments. Subsequent intrusive events began in the Late Mesozoic ending with the Reef of Rock granite. Movements on the Geeseman Fault and other northwest-trending faults during Basin and Range time resulted in the formation of the down-dropped graben of the Canada del Oro valley. INTRODUCTION The headwaters region of the Canada del Oro is located approxi- mately 32 km (20 mi) north of Tucson, Arizona in the Santa Catalina Mountains (Fig. 1). The region under consideration lies between the Oracle and Samaniego ridges and between Catalina Camp in the south and Coronado Camp in the north (Fig. 2, in pocket). The rugged topography varies in elevation from 2344 m (7688 ft) to 1280 m (4198 ft) and is well dissected by intermittent streams. Vegetation changes from pine-oak woodlands in the higher elevations to desert grasslands in the lower por- tions. Ground cover and talus are locally extensive and may limit out- crops to as little as 40% in the higher elevations and in the more vegetated stream valleys.