Western Michigan University ScholarWorks at WMU Master's Theses Graduate College 4-2018 Geologic Mapping of the Bronson North and Bronson South 7.5-Minute Quadrangles, Branch County, Michigan Karl John Backhaus Follow this and additional works at: https://scholarworks.wmich.edu/masters_theses Part of the Geology Commons, Geophysics and Seismology Commons, and the Glaciology Commons Recommended Citation Backhaus, Karl John, "Geologic Mapping of the Bronson North and Bronson South 7.5-Minute Quadrangles, Branch County, Michigan" (2018). Master's Theses. 3432. https://scholarworks.wmich.edu/masters_theses/3432 This Masters Thesis-Open Access is brought to you for free and open access by the Graduate College at ScholarWorks at WMU. It has been accepted for inclusion in Master's Theses by an authorized administrator of ScholarWorks at WMU. For more information, please contact [email protected]. GEOLOGIC MAPPING OF THE BRONSON NORTH AND BRONSON SOUTH 7.5-MINUTE QUADRANGLES, BRANCH COUNTY, MICHIGAN by Karl John Backhaus A thesis submitted to the Graduate College in partial fulfillment of the requirements for the degree of Master of Science Geosciences Western Michigan University April 2018 Thesis Committee: Alan Kehew, Ph.D., Advisor William Sauck, Ph.D. Robb Gillespie, Ph.D. Copyright by Karl John Backhaus 2018 GEOLOGIC MAPPING OF THE BRONSON NORTH AND BRONSON SOUTH 7.5-MINUTE QUADRANGLES, BRANCH COUNTY, MICHIGAN Karl John Backhaus, M.S. Western Michigan University, 2018 This study contributes to a better understanding of the glacial history of southwest Michigan through detailed surficial geologic and bedrock topography mapping within the Bronson North and Bronson South Quadrangles in Branch County, Michigan. This project was supported during the summer of 2017 by the USGS EDMAP program in conjunction with the Michigan Geological Survey. Hand-auger borings, grain size analysis tests, passive seismic depth-to- bedrock measurements, and ground penetrating radar transects were collected for this study. There are 350 feet of bedrock relief from west to east across the quadrangles, including a bedrock cuesta of Mississippian Coldwater Shale. This cuesta underlies an area of streamlined drumlins in the northern portion of the study area, which become more diffuse to the west of the study area. Drumlins mapped in the area are composed of diamicton occurring at elevations above 900ft (274m) in the northern quadrangle. Coarse-grained outwash occurs in swales between the drumlins. The southern quadrangle is predominantly composed of coarse-grained outwash, which exhibits a hummocky topographic surface. Surficial sediments in this upland were deposited within a braided stream system during deglaciation. Glaciofluvial sediments within these quadrangles were deposited by meltwater streams derived from the Huron-Erie and Saginaw Lobes of the Laurentide Ice Sheet during final retreat approximately 19,000 cal yr. ACKNOWLEDGEMENTS I would like to thank Dr. Alan Kehew. His patience, advice and support throughout this entire project is something that I cannot thank him for enough. I would also like to thank my other committee members. Dr. William Sauck, for his guidance in the field, and the many hours he spent helping process and gather data for this project. Dr. Robb Gillespie for his support through this entire project. I would also like to express my upmost gratitude to thank Dr. Andrew Kozlowski. The many years I spent under his guidance as an intern with the NYSGS inspired me to come to Western Michigan University in search of my master’s degree in Quaternary geology. Thank you to John Esch, with the MDEQ, for his many hours of guidance and days in the field with the Tromino, and the HVSR method. To the many students at Western Michigan University who helped collect soil samples and gather data in both the lab and the field, Joseph Swarz, Benjamin Seiderman, and Tyler Norris, I cannot thank you enough. Many thanks to Sita Karki, for her many hours and patience with me during this project. To my girlfriend, Emily Ward, for dealing with my long hours in the field and the lab and supporting me through the toughest times during this project. I cannot thank you enough. Lastly, I would like to thank my family. The long path that led me here to Western Michigan University, they were right by my side. Lastly, I thank my parents, for the many, many years of guidance and support through the many trials and tribulations that I have had to go through to achieve my dreams. Karl John Backhaus ii TABLE OF CONTENTS ACKNOWLEDGEMENTS ......................................................................................................... ii LIST OF FIGURES ...................................................................................................................... v CHAPTER I. INTRODUCTION ............................................................................................................... 1 Study Area ........................................................................................................................ 1 Objectives ......................................................................................................................... 3 II. GEOLOGY......................................................................................................................... 5 Bedrock Geology .............................................................................................................. 5 Glaciation .......................................................................................................................... 7 Previous Studies .............................................................................................................. 17 III. METHODS ..................................................................................................................... 35 Surficial Sediment Analysis ............................................................................................ 35 Ground Penetrating Radar ............................................................................................... 38 Passive Seismic Surveying ............................................................................................. 44 Geographic Information Systems ................................................................................... 50 IV. RESULTS ....................................................................................................................... 52 Sediment Characteristics of the Bronson North Quadrangle .......................................... 52 Sediment Characteristics of the Bronson South Quadrangle .......................................... 55 Ground Penetrating Radar in the Bronson South Quadrangle ........................................ 60 Soils of the Quadrangles ................................................................................................. 60 Landforms ....................................................................................................................... 60 iii Table of Contents -- Continued CHAPTER Bedrock Topography ...................................................................................................... 63 Drift Thickness................................................................................................................ 68 Error Analysis ................................................................................................................. 68 V. DISCUSSION .................................................................................................................. 71 Bedrock Topography ...................................................................................................... 71 Landforms ....................................................................................................................... 75 Sediment-Landform Assemblages and Bed Conditions ................................................. 79 Timing and Possible Sequence of Events ....................................................................... 80 Comparison with Previous HVSR Studies ..................................................................... 84 VI. CONCLUSIONS ............................................................................................................ 86 APPENDICES A. Bronson North Sieve Analysis Results .................................................................... 90 B. Bronson South Sieve Analysis Results .................................................................. 141 C. HVSR Survey Results ........................................................................................... 189 BIBLIOGRAPHY ..................................................................................................................... 195 PLATES .................................................................................................................................... 202 A. Surficial Geology of the Bronson North 7.5-Minute Quadrangle, Branch County, Michigan ................................................................................................... 202 B. Surficial Geology of the Bronson South 7.5-Minute Quadrangle, Branch County, Michigan and Steuben and Lagrange Counties, Indiana ........................... 204 iv LIST OF FIGURES 1. Study Area ........................................................................................................................ 2 2. Regional Bedrock Map ....................................................................................................