Subsidence Analysis of the Midland Basin and Eastern Shelf of West Texas: Implications for Ancestral Rocky Mountain Timing and Deformation by Cameron Elizabeth Ramsey, B.S. A Thesis In Geology Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCES Approved Dr. Dustin Sweet Chair of Committee Dr. George Asquith Dr. Neo McAdams Mark Sheridan Dean of the Graduate School May, 2020 Copyright 2020, Cameron Elizabeth Ramsey Texas Tech University, Cameron Elizabeth Ramsey, May 2020 ACKNOWLEDGMENTS I would like to thank my advisor Dr. Dustin Sweet for all his guidance and support throughout my time at Texas Tech University. Without your help and patience this project would not have been possible. I would also like to thank my committee members Dr. George Asquith and Dr. Neo McAdams. Dr. George Asquith is a wealth of knowledge and I’m very grateful for all your help with the well log analysis. To Dr. Neo McAdams, thank you for all your assistance and insightful questions regarding the biostratigraphic data and graphic method analysis. Additionally, I would like to thank the American Association of Petroleum Geologist Southwest Section for their financial support. I am immensely grateful to the organization for the grant I received for this project. Without this financial aid it would have be difficult to acquire the necessary well logs for the subsidence analysis. Last but not least, I would like to thank my friends and family, without your love and support I would not have gotten this far in my academic career. ii Texas Tech University, Cameron Elizabeth Ramsey, May 2020 TABLE OF CONTENTS ACKNOWLEDGMENTS .................................................................................... ii ABSTRACT .......................................................................................................... vi LIST OF TABLES ............................................................................................. viii LIST OF FIGURES ............................................................................................. ix CHAPTER I ........................................................................................................... 1 INTRODUCTION ................................................................................................. 1 Motivation ......................................................................................................... 1 Hypothesis Statement ........................................................................................ 3 Significance ....................................................................................................... 3 CHAPTER II ......................................................................................................... 4 GEOLOGIC BACKGROUND ............................................................................ 4 Geologic Setting ................................................................................................ 4 Chronostratigraphy ............................................................................................ 7 Atokan Stage ............................................................................................... 8 Strawn Stage ............................................................................................... 9 Canyon Stage .............................................................................................. 9 Cisco Stage ................................................................................................ 10 Wolfcamp Stage ........................................................................................ 11 Leonardian Stage ....................................................................................... 12 CHAPTER III ..................................................................................................... 13 METHODS .......................................................................................................... 13 Biostratigraphic Data ...................................................................................... 13 Basin Subsidence ............................................................................................ 15 Site Generation .......................................................................................... 15 Decompaction ................................................................................................. 17 Site C ......................................................................................................... 19 Site D ......................................................................................................... 20 Site E ......................................................................................................... 20 Site F ......................................................................................................... 20 iii Texas Tech University, Cameron Elizabeth Ramsey, May 2020 Graphic Method for Correlation...................................................................... 22 CHAPTER IV ...................................................................................................... 25 RESULTS ............................................................................................................ 25 Subsidence Analysis ....................................................................................... 25 Eastern Shelf Subsidence Analysis ................................................................. 25 Site A ......................................................................................................... 25 Site B ......................................................................................................... 27 Site C ......................................................................................................... 27 Midland Basin Subsidence Analysis ............................................................... 27 Site D ......................................................................................................... 28 Site E ......................................................................................................... 28 Site F ......................................................................................................... 29 Graphic Method for Correlation...................................................................... 30 Shelf-to-Shelf Comparisons ...................................................................... 30 Basin-to-Basin Comparisons ..................................................................... 32 Shelf-to-Basin Comparisons ..................................................................... 34 CHAPTER V ....................................................................................................... 36 DISCUSSION ...................................................................................................... 36 Tectonic Subsidence Analysis ........................................................................ 36 Eastern Shelf ............................................................................................. 36 Midland Basin ........................................................................................... 36 Rates of Tectonic Subsidence ................................................................... 38 Sediment Accumulation .................................................................................. 38 Graphic Method for Correlation...................................................................... 40 Shelf-to-Shelf Comparisons ...................................................................... 40 Basin-to-Basin Comparisons ..................................................................... 40 Shelf-to-Basin Comparisons ..................................................................... 41 Evolution of the Midland Basin and Eastern Shelf ......................................... 43 Atokan ....................................................................................................... 43 Strawn ....................................................................................................... 43 Canyon ...................................................................................................... 43 Cisco .......................................................................................................... 44 Wolfcamp .................................................................................................. 44 Leonardian ................................................................................................ 45 iv Texas Tech University, Cameron Elizabeth Ramsey, May 2020 Implications for Ancestral Rocky Mountains ................................................. 45 CHAPTER VI ...................................................................................................... 49 CONCLUSIONS ................................................................................................. 49 BIBLIOGRAPHY ............................................................................................... 50 APPENDIX A ...................................................................................................... 56 PABZT Data Distribution ............................................................................... 56 Backstripping Data .......................................................................................... 57 Individual Tectonic Subsidence