The Cretaceous Evolution of the Lhasa Terrane, Southern Tibet Item Type text; Electronic Dissertation Authors Leier, Andrew 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 13:36:38 Link to Item http://hdl.handle.net/10150/193796 THE CRETACEOUS EVOLUTION OF THE LHASA TERRANE, SOUTHERN TIBET by Andrew Lawrence Leier 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 2 0 0 5 2 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE As members of the Dissertation Committee, we certify that we have read the dissertation prepared by: Andrew L. Leier entitled: The Cretaceous Evolution of the Lhasa Terrane, Southern Tibet and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of: Doctor of Philosophy _______________________________________________________________________ Date: 11/07/05 Peter DeCelles _______________________________________________________________________ Date: 11/07/05 Paul Kapp _______________________________________________________________________ Date: 11/07/05 Jay Quade _______________________________________________________________________ Date: 11/07/05 George Gehrels _______________________________________________________________________ Date: 11/07/05 George Zandt Final approval and acceptance of this dissertation is contingent upon the candidate’s submission of the final copies 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 requirement. ________________________________________________ Date: 11/07/05 Dissertation Director: Peter G. DeCelles 3 STATEMENT BY THE 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 borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgement 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 of 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. Signed: Andrew Leier 4 ACKNOWLEDGEMENTS I owe a great deal to many individuals, more than I can mention in the limited space provided. I would like to thank my advisor, Dr. Pete DeCelles, for his great tutelage and unending patience. I would also like to thank Dr. DeCelles for all of the support he provided, financial and otherwise; I owe him a lot. I am grateful to the members of my committee for all of the help they provided: Dr. Paul Kapp, who led me through Tibet and was always available for questions and discussion; Dr. Jay Quade, who introduced me to stable isotopes and many other aspects of geology; Dr. George Gehrels, who patiently showed me the methods of detrital zircon analysis; and Dr. George Zandt, who introduced me to the processes acting within and below the lithosphere. Many people have assisted me during my time at The University of Arizona. Special thanks to Dave Barbeau for his assistance and instruction and D Robinson for all of her help; I also thank my officemate Aaron Martin for helpful discussions. I want to say ‘thank you’ to Shundong He and Dan Eisenberg for their assistance with field- work. I would like to thank many more people individually and at length, but given the spatial constraints I will simply list their names here: John Chesley, David Dettman, Matt Fabijanic, Majie Fan, Jen Fox, Facundo Fuentes, Jerome Guynn, Dick Hay, Brian Horton, Jessica Kapp, Ding Lin, Alex Pullen, Joel Saylor, Bob Scott, Victor Valencia, John Volkmer, Ross Waldrip, and the Tibetans who helped me while I was in their territory. In addition, there are others to whom I am indebted: Stacie Gibbins, Alex Bump, Nadine McQuarrie, Ofori Pearson, J. Mike Boyles, Ron Steel, Edward Cotter, Mary-Beth Gray, Jim Steidtmann, Nathan English, and Andrea Fildani. I sincerely thank all of the people listed in this and the preceding paragraph. If there are other names that have slipped my mind, I apologize, but please believe me when I say that I am grateful for the help you provided. My family has been very supportive during this time. I thank my brother Joe and my sister Rachel for their encouragement, interest, and support. I would like to thank my parents, Carl and Jolene Leier, for their love, patience, interest, encouragement, and financial assistance. I would also like to thank my parents for all of the support they have provided. 5 TABLE OF CONTENTS LIST OF FIGURES ......................................................................................................9 LIST OF TABLES ......................................................................................................11 ABSTRACT.................................................................................................................12 CHAPTER 1: INTRODUCTION..............................................................................13 CHAPTER 2: FACIES, COMPOSITION, DETRITAL ZIRCON GEOCHRONOLOGY AND TECTONIC IMPLICATIONS OF LOWER CRETACEOUS STRATA IN THE LHASA TERRANE OF SOUTHERN TIBET .......................................................................................................................................18 ABSTRACT............................................................................................................18 INTRODUCTION ..................................................................................................19 SETTING................................................................................................................21 FACIES...................................................................................................................23 LITHOFACIES ASSOCIATIONS – NORTHERN AREA ...................................23 Offshore Marine Lithofacies Association.........................................................24 Description..................................................................................................24 Interpretation ..............................................................................................25 Northern Fluvial Lithofacies Association.........................................................25 Description..................................................................................................25 Interpretation ..............................................................................................27 Northern Limestone Lithofacies Association ...................................................28 Description..................................................................................................28 Interpretation ..............................................................................................28 LITHOFACIES ASSOCIATIONS – SOUTHERN AREA....................................29 Lagoonal Lithofacies Association.....................................................................29 Description..................................................................................................29 Interpretation ..............................................................................................30 Shoreface Lithofacies Association....................................................................30 Description..................................................................................................30 Interpretation ..............................................................................................31 Southern Fluvial Lithofacies Association.........................................................32 Description..................................................................................................32 Interpretation ..............................................................................................33 Southern Limestone Lithofacies Association ...................................................33 Description..................................................................................................33 Interpretation ..............................................................................................34 PALEOCURRENT MEASUREMENTS ...............................................................35 PETROGRAPHY ...................................................................................................36 6 TABLE OF CONTENTS - Continued Northern Study Area.........................................................................................36 Southern Study Area.........................................................................................37 DETRITAL ZIRCON GEOCHRONOLOGY........................................................38 Methods.............................................................................................................38