Links between sediment accumulation rates and the development of alluvial architecture: Triassic Ischigualasto Formation, northwestern Argentina Item Type text; Dissertation-Reproduction (electronic) Authors Shipman, Todd Christopher 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 14:13:22 Link to Item http://hdl.handle.net/10150/280652 LINKS BETWEEN SEDIMENT ACCUMULATION RATES AND THE DEVELOPMENT OF ALLUVIAL ARCHITECTURE: TRIASSIC ISCHIGUALASTO FORMATION, NORTHWESTERN ARGENTINA by Todd Christopher Shipman A Dissertation Submitted to the Faculty of the DEPARTMENT OF GEOSCIENCES In Partial Fulfillment of the Requirements For the Degree of DOCORATE IN PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 2004 UMI Number: 3145131 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. UMI UMI Microform 3145131 Copyright 2004 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 THE UNIVERSITY OF ARIZONA ® GRADUATE COLLEGE As m,enibers cf the Final Examination Committee, we certify that we have read the dissertation prepared bv Todd C. Shipman entitled Links between sediment accumulation rates and the development of alluvial architecture; Triassic Ischigualasto Formation, northwestern Argentina and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy 4' ^ 1 •'i 'Z Dr/A Peter DeCelles Date Qa^C^— H-. 2^- Dr, J/^ Quade Date Dr. Clement• Ch - "ate M 1 I Uv~. ilori Pellet Dat - M i?! I C Df.^udy Parrish Date 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 Chat I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. i-i ! 7 i Dis^rtation Director Date Dru/ Judy Parrish 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 University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special pennission, 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. SIGNED; 4 ACKNOWLEDGEMENTS I am grateful to the many individuals who provided expertise helped me to complete and develop my resetirch. I thank the members of my committee, Drs. Judith Totman Parrish, Clement Chase, Jay Quade, Peter DeCelles, and Jon Pelletier for helpful discussion and analytical advice along the way. I thank Dr. J.T. Parrish for suggesting this research in the Ischigualasto Basin and for providing funding for my second year in the field. Thanks to Drs. Brian Currie, of University of Miami of Ohio, Neil Tabor, of Southern Methodist University, and Isabel Montanez for their insight and direction of this research. I am especially grateful to Dr. Juan Pablo Milana, from Universidad Nacional de San Juan, and Dr. Martinez, from the Museo de Ciencias Naturales in San Juan, Argentina, whose guidance and assistance in the field were vital in the conducting of this research. Thanks to the field assistance Carina Colombi. Without the support of my wife, Esther Kim; my parents, Karin Shipman and Ray Hoehle; and my sister, Tanja Shipman, all of this would not be possible. Thanks to all the distraction and insightful conversation from my colleagues Dave Barbeau, Jason Barnes, and Jim Morrison. Financial support for fieldwork was provided by student research grants from the Department of Geosciences, Chevron Grant, Harvard Travel Grant, and National Geographic Society. The Geological Society of America and American Association of Petroleum Geologists funded laboratory research. TABLE OF CONTENTS LIST OF ILLUSTRATIONS 7 LIST OF TABLES 13 ABSTRACT 14 CHAPTER 1: LITERATURE REVIEW AND STATEMENT OF PROBLEM 16 Statement of Problem 16 Previous work 17 Methods 18 Explanation of Dissertation Format 18 WORKS CITED 20 CHAPTER 2: PRESENT STUDY 23 APPENDIX A: DEPOSITIONAL ENVIRONMENTS OF THE UPPER TRIASSICISCHIGUALASTO FORMATION, AGUA DE LA PENA GROUP, SAN JUAN PROVINCE, ARGENTINA 25 Abstract 25 Introduction 25 Previous Work 26 Tectonic, Climatic, and Depositional Setting 29 Paleoclimate 29 Methods 31 Results 32 Paleosol Classification 32 Channel Classification 34 Axial Basin Stratigraphy 35 Discussion 37 Paleosol Interpretation 37 Channel Interpretation 41 Regional Interpretation 43 Chaimel Sandstone Trends within the Basin 45 Floral Preservation 47 Conclusion 48 References 50 APPENDIX B:SEDIMENTATION RATES AND THEIR EFFECTS ON FLUVIAL ARCHITECTURE AND PALEOSOL DEVELOPMENT WITHIN THE ISCHIGUALASTO BASIN 66 Abstract 66 Introduction 66 Sedimentary Architectural Response to Accommodation and Sediment Supply Rates 69 Rift Basin Application of this Model 73 6 TABLE OF CONTEmS-Continued Methods and Data Collection 75 Chronostratigraphy 76 Paleocurrents 76 Bed Interconnectedness 76 Avulsion Frequency 76 Results 77 Chronostratigraphy 77 Paleocurrents 77 Bed Interconnectness 77 Paleosols 78 Avulsion Frequency 78 Discussion 79 Chronostratigraphy 79 Paleocurrents 79 Paleosols 80 Bed Interconnectness 83 Discussion of Base-Ievel/Climate/Tectonic shifts 84 Conclusions 88 References 90 APPENDIX C:MODEL FOR THE TECTONOSEDIMENTARY BASIN FILL OF THE TRIASSIC ISCHIGUALASTO BASIN, NORTHWESTERN ARGENTINA 110 Abstract 110 Introduction Ill Basin Fill Sequence 114 Regional Tectonics and Volcanism 120 Local Triassic Tectonics and Volcanism 123 Regional Paleogeography and Paleoclimate 124 Dates/Biostratigraphy 125 Discussion 127 Tectonostratigraphic Framework 127 Climate 132 Temporal Distribution of Volcanic Activity 134 Conclusion 135 References 137 APPENDIX D: SECTION 1 151 APPENDIX E: SECTION 2 167 APPENDIX F: SECTION 3 178 7 LIST OF ILLUSTRATIONS Figure A-1. This geologic map of the Ischigualasto Basin shows the entire extent of outcrops within the basin. Valle Fertil is the boundary fault that controls accommodation in the basin. Black lines and numbers represent the location of measured sections and their corresponding numbers. These sections were measured perpendicular to strike of the Ischigualasto Formation (map modified from Milana and Alcober, 1994) 55 Figure A-2. The stratigraphy of Ischigualasto Basin fill sequence, deposited during the Triassic Period 56 Figure A-3. Classification of the Ischigualasto Formation paleosols based on Mack et al. (1993) 57 Figure A-4 (A), Pedotype A is the most immature paleosol classified in the Ischigualasto Formation 58 Figure A-4 (B), Pedotype B is a gleyed paleosol with redoximorphic colors 58 Figure A-4 (C), Pedotype D has an illuviated clay horizon and abimdant root traces 58 Figure A-4 (D), Pedotype C represents the most immature of the carbonate- bearing paleosols and contains nodular carbonate 58 Figure A-4 (E), Pedotype F is the most mature soil type, with illuviated clay and coalesced carbonate nodules 58 Figure A-4 (F), Pedotype E is similar to pedotype C; however the secondary nodular carbonate is more developed 58 Figure A-5, Ischigualasto Formation sandstone architecture 59 Figure A-6 (A), Type 4 included a type 3 bed overlain by a type 1 or 2 bed. The bedded horizons in the type 3 channel sandstone are oblique views of lateral accretion set 60 Figure A-6 (B), Type 1 and 2 are deposited by similar charmels; however the type 2 represents multi-story assemblage of type 1 60 8 LIST OF ILLUSTRATIONS'Continued Figure A-6 (C), Type 6 channel sandstones have high concentrations of mud and blend into the surrounding overbank deposits 60 Figure A-6 (D), Plant material is preserved within abandoned channel deposits, which formed lakes near active channels 60 Figure A-6 (E), Type 3 channel sandstone beds with pedogenic modification along the lateral accretion beds suggest an ephemeral nature to this channel 60 Figure A-6 (F), Type 5 channel sandstone beds are shown here branching on the paleofloodplain 60 Figure A-7, Channel sandstone beds were mapped out in a 1.5 km wide swath adjacent to the location where section 1 was measured. Paleocurrent rose diagrams are placed at the locations where they were measured. Along the right side of the figure, numbers correspond