A structural study of the east end of the Catalina Forerange, Pima County, Arizona Item Type text; Dissertation-Reproduction (electronic); maps Authors Peterson, Richard Charles, 1931- 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 29/09/2021 10:35:10 Link to Item http://hdl.handle.net/10150/565172 A STRUCTURAL STUDY OF THE EAST END OF THE CATALINA FORERANGE, PIMA COUNTY, ARIZONA >• Richard C. Peterson A Dissertation Submitted to the Faculty of the DEPARTMENT OF GEOLOGY In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 19 6 8 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE I hereby recommend that this dissertation prepared under my direction by _______________ Richard C. Peterson_________________ entitled A Structural Study of the East End of the__________ Catalina Forerange, Pima County, Arizona___________ be accepted as fulfilling the dissertation requirement of the degree of __________________ Doctor of Philosophy________________ Date After inspection of the dissertation, the following members of the Final Examination Committee concur in its approval and recommend its acceptance:* V / f / ^ 9 jlUi n x W. W e X *+ j 1 <7 ---<///?/£>?/ ----- 6 . ^ A t / e r 7 Z *This approval and acceptance is contingent on the candidate's adequate performance and defense of this dissertation at the final oral examination. The inclusion of this sheet bound into the library copy of the dissertation is evidence of satisfactory performance at the final examination. STATEMENT BY AUTHOR This dissertation 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 bor­ rowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or re­ production of this manscript 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 in­ terests of scholarship. In all other instances, however, permission must be obtained from the author. 7 '— '— - SIGNED: ACKNOWLEDGEMENTS For his advice and encouragement throughout all phases of this investigation, and for serving as dissertation director, the author wishes to express his sincere appreciation to Dr. Evans B. Mayo. The assistance of Professors L.M. Gould, E.J. McCullough, Jr., J.F. Schreiber, Jr,, and R.F. Wilson, who read the manuscript and offered many helpful suggestions, is gratefully acknowledged. The many discussions with fellow graduate students, in particular Mr. C.J* Waag, have been most beneficial, and the aid of Mr. C.O. Larson in preparing the photographs is greatly appreciated. The author offers his thanks to the personnel at the Federal Youth Camp and the Sabino Canyon Recreation Area for the many courtesies extended to him. Thanks are due also to an anony­ mous donor for his generous financial support. To his wife who aided immensely during the course of this study, the author is greatly in­ debted. iii TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS......................................... vi LIST OF T A B L E S ............................ ix ABSTRACT.................................. x INTRODUCTION ............................................. 1 1-4 m cn m cn 1-4 mvo Location.............. Accessibility ........ Topography. ...... Objectives............ Method of Investigation Previous Work ........ THE ROCKS............................................. .. 9 Metamorphic Rocks ................................... 9 General Statement. ........................... 9 Seven Falls Gneiss ............................ 11 Soldier Canyon Gneiss.......................... 15 Gibbon Mountain Gneiss ........................ 27 Sabino Narrows Gneiss.......................... 31 Thimble Peak Gneiss............................ 36 East Fork G n e i s s ............................... 40 Granitic Gneiss of the Main Range.............. 45 Silicified Gneiss............................... 46 Dike Rocks........................................... 47 Aplites and Lamprophyres ...................... 47 Sedimentary R o c k s ................................... 48 Rillito B e d s ................................... 48 Older Alluvium-Terrace Deposits. .............. 48 Younger Alluvium.............................. 49 DESCRIPTION OF STRUCTURAL ELEMENTS ...................... 50 Foliation........................................... 50 Lineation........................ 53 Folds ............................................... 56 Major Anticlinal Structures.................... 56 Minor Anticlinal Structures. ................... 58 Glide Folds..................................... 58 iv V TABLE OF CONTENTS— Continued Page Fractures................ .............................. 67 J o i n t s .......................................... 67 F a u l t s ............................................. 71 ALTERNATIVE HYPOTHESES ............................... .... 80 ORIGIN OF THE FORERANGE GNEISSES ............................ 82 Original R o c k ........................................... 82 Age of the Rock Transformation.......................... 83 STRUCTURAL HISTORY ........................................... 86 RELATION OF CURRENT STUDY TO PREVIOUS STUDIES IN THE SANTA CATALINA MOUNTAINS. ....................... 96 SUMMARY............................. 99 LIST OF REFERENCES............................................. 101 LIST OF ILLUSTRATIONS Figure Page 1. Location m a p ............................. 2 2. Foliation, major folds, and glide directions .... in pocket 3. Lineation and fracture pattern .................... in pocket 4. Orientation diagrams of lineation and fracture pattern ....................................... in pocket 5. Geologic cross sections of the east end of the Catalina Forerange, Pima County, Arizona. in pocket 6. Geologic cross sections of the east end of the Catalina Forerange, Pima County, Arizona. in pocket 7. Seven Falls G n e i s s .................. 13 8. Cliffs formed of Seven Falls Gneiss...... 13 9. Seven Falls Gneiss-Soldier Canyon Gneiss contact . 16 10. Large inclusion of Soldier Canyon Gneiss in Seven 16 Falls Gneiss ................................ 11. Parallelism of bands in the Soldier Canyon Gneiss. 18 12. Irregular light bands in the Soldier Canyon Gneiss . 18 13. Complexities in a dark band of Soldier Canyon Gneiss 19 14. Typical field exposure of Soldier Canyon Gneiss. 21 15. Parallelism of biotite in dark band of Soldier Canyon Gneiss ................................ 23 16. Contorted foliation in a dark band of Soldier Canyon Gneiss ................................. 23 17. Soldier Canyon Gneiss-Gibbon Mountain Gneiss contact....................................... 26 vi vii LIST OF ILLUSTRATIONS— Continued Figure Page 18. Irregular pods of Soldier Canyon Gneiss engulfed by granitic gneiss of the main range.......... 26 19. Gibbon Mountain Gneiss ............................. 28 20. Gibbon Mountain Gneiss forming ridge west of Bear C a n y o n ......................... 28 21. Slope forming Sabino Narrows Gneiss........ 32 22. Fresh sample of Sabino Narrows Gneiss...... 34 23. Field exposure of Sabino Narrows Gneiss.... 34 24. Exposure of Thimble Peak Gneiss showing fresh and weathered surfaces......................... 38 25. Spires of Thimble Peak Gneiss............. 38 26. Thimble Peak Gneiss-East Fork Gneiss contact .... 41 27. East Fork G n e i s s .............................. .. 41 28. Field exposure of East Fork Gn e i s s ............ 43 29. Dark layers of East Fork Gneiss intertongued with the granitic gneiss of the main r a n g e ........ 43 30. Flattened feldspar augen and biotite flakes. .... 52 31. Two directions of foliation in the granitic gneiss of the main range...................... 52 32. Stretched quartz on top of pegmatitic ba n d . 54 33. Lineation of minor fold a x e s ............ 54 34. Geologic map of the Santa Catalina Mountains .... in pocket 35. Minor fold in Soldier Canyon Gneiss........ 59 36. Pegmatitic pod in Soldier Canyon Gneiss... 59 37. Cliff south of Seven Falls in Bear Canyon. 61 viii LIST OF ILLUSTRATIONS— Continued Figure Page 38. Simple glide folds. ^ , 63 39. Axial region of simple glide fold.................. 63 40. Fracture f a n .................................. 64 41. Cascade of simple glide folds...................... 64 42. Bent axial plane in glide f o l d .............. 65 43. Rootless simple glide f o l d ........................ 65 44. Crumpled glide folds .............. ........ 66 45. Size variations of crumpled glide folds............ 66 46. Crumpled glide fold on the flank of a minor fold . 68 47. Steeply dipping foliation in the Soldier Canyon Gneiss. ....................................... 73 48. Variations in dip of light and dark bands.......... 73 49. Crumpled glide folds near the center of the Molino Basin-Soldier Canyon Fracture Zone graben . 74 50. Crumpled glide folds associated with the Molino Basin-Soldier Canyon Fracture Zone. ...... 75 LIST OF TABLES