Faulting and basin geometry beneath the Great Salt Lake: implications for basin evolution and cenozoic extension Item Type text; Dissertation-Reproduction (electronic) Authors Mohapatra, Gopal Krishna, 1968- 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 24/09/2021 11:07:02 Link to Item http://hdl.handle.net/10150/565551 Faulting and Basin Geometry Beneath the Great Salt Lake: Implications for Basin Evolution and Cenozoic Extension by Gopal Krishna Mohapatra A Dissertation Submitted to the Faculty of the DEPARTMENT OF GEOSCIENCES In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 1996 2 THE UNIVERSITY OF ARIZONA ® GRADUATE COLLEGE As members of the Final Examination Committee, we certify that we have read the dissertation prepared by Gopal Krishna Mohanatra___________ entitled Faulting and Basin Geometry Beneath the Great Salt T.akp; Implications for Basin Evolution and Cenozoic Extension and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy Final approval and acceptance of this dissertation is contingent upon the candidate's submission of the final copy of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation As/aorzi_EL /9 9 6 Date 3 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 Uni­ versity Library to be made available to borrowers under rules of the library. Brief quotations from this dissertation are allowable without special per­ mission, 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 or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. 4 ACKNOWLEDGMENTS This dissertation has got the touch of many people, without which it would not have been a reality. To my principal advisor, Roy A. Johnson, I extend special thanks for providing motivation, technical expertise, moral support and guidance during my graduate studies at the University of Arizona. I also thank my other committee members for their advice and criticism, including Clem Chase, Randy Richardson, Susan Beck and George Davis. I am very grateful to Steve Sorenson, who was a big help in solving computer-related problems, and thus played a key role in the completion of the thesis. My sincere thanks to the BIG GUYS: Jim Coogan and Kurt Constenius, for teaching me geology of areas around Great Salt Lake. Discussions with them helped this dissertation see the daylight. A special thanks goes to Helge Gonnerman for many helpful late night discussions about research and our goals in life. Thanks to Andy Freed for teaching me finite element modeling. I am grateful to H. J. Melosh of Lunar and Planetary Laboratory for letting me use the finite element code TECTON. I thank Carl Mitchell, Peangta Satarugsa, George Petropoulos and Joy deep Haidar for their help. I extend my heartfelt thanks to all, in and out of the department, whose friendship and company helped me go through the graduate program successfully. Finally, and most importantly, my wife Reva is especially acknowledged for her help, support, and patience, which lessened the stress of the graduate program to a great extent. Funding for this dissertation was provided by National Science Foundation grants EAR-9205065 and EAR-9219505. Summer funding was provided by De­ partment of Geosciences, and Graduate College. Amoco Production Company provided the seismic, borehole, and gravity data used for the study. DEDICATION To my Grandfather Parents and Parents-in-law 6 TABLE OF CONTENTS LIST OF F I G U R E S ............................................................................................. 8 LIST OF T A B L E S ................................................................................................ 9 A B S T R A C T ............................................................................................................ 10 CHAPTER 1 Introduction ....................................................... 12 1.1 The Approach Used and Chapter R e v ie w ......................................... 13 CHAPTER 2 Basin and Fault Geometry, and Extension .............. 15 2.1 In trod u ction .................... 15 2.2 Tectonic and Geological Setting ......................................................... 16 2.3 Data . ....................... 20 2.3.1 Seismic and Gravity Data . ............... 20 2.3.2 Bore-hole Data ....................... 21 2.4 Basin G eo m etry ........................................................................................ 22 2.5 Fault G e o m e tr y ........................................................................................ 42 2.6 Onset of E xtension.................................................................................... 46 2.7 Extension Amount and Fault Slip ...................................................... 48 2.8 Isopach A n a ly sis........................................................................................ 53 2.8.1 Oligocene.................... 53 2.8.2 M io c e n e ......................................................... 54 2.8.3 P lio c e n e ................................................................................. 54 2.8.4 Quaternary.................................................. 55 2.9 Sedimentation R a tes.................................................. 61 2.10 Discussion ................ 62 2.11 Conclusions.................................................................................................. 65 CHAPTER 3 3-D constraints on Tertiary Deformation and Fault Geometry in the Great Salt Lake Basin, Utah: Their Structural and T ecton ic I m p lic a tio n s ........................................................................................... 66 3.1 In trod u ction .............................................................................................. 66 3.2 Theory ......................................................................................................... 68 3.2.1 Role of compaction .................................... 72 3.2.2 Determination of parameters and fault geometry . 73 3.3 Synthetic E x a m p le s.............................. 73 3.4 The Great Salt Lake ................................................................................. 75 3.4.1 Inverse A p p ro a ch ................................................................ 87 3.5 R e s u lts ........................................................................................................ 87 3.5.1 Deformation P a ra m eters........................................ 88 3.5.2 Fault G eom etry.................................................................... 92 3.6 Structural and tectonic im p lications................................................... 93 7 TABLE OF CONTENTS — Continued 3.6.1 Extension d irectio n ............................................................. 93 3.6.2 Simple shear deformation . ......................................... 100 3.6.3 Out of plane deform ation......................................................100 3.6.4 Fault Geometry ...................................................................... 101 3.7 Conclusions ........................... 101 CHAPTER 4 Localization of Listric Faults at Thrust Fault Ramps beneath the Great Salt Lake Basin, Utah; Evidence from Seismic Im aging and F in ite E lem ent M o d e lin g ...................................................... 103 4.1 In trod u ction ................................................................................................. 103 4.2 Data and Interpretation................ 105 4.2.1 Geology .............................. 105 4.2.2 Seismic D a ta ............................................................................. 108 4.2.3 Gravity D a ta .............................. 116 4.2.4 Bore-hole Data .......................... 117 4.2.5 Structural and Tectonic Interpretation .............................. 117 4.3 Finite Element M odeling ........................................... 123 4.4 Deviatoric Stress and Proximity to Failure............................................128 4.5 Results and Discussion ....................... 130 4.5.1 Location and orientation of incipient faulting ................133 4.5.1.1 Extension on the listric-normal fa u lt ..................... 136 4.6 Conclusions.....................................................................................................141 C H A P T E R 5 C O N C L U S IO N S .................................................................... 142 APPENDIX A INTERVAL VELOCITY USED FOR DEPTH CON­ V E R S IO N ................................................................................................................... 145 REFERENCES 8 LIST