AN EVALUATION OF DIGITAL ELEVATION MODELS AND GEOTECHNICAL PROPERTIES OF THE GLACIAL DEPOSITS IN FRANKLIN COUNTY, OHIO, USING A GEOGRAPHIC INFORMATION SYSTEM DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Jeffrey K. Bates, M.S. ***** The Ohio State University 2007 Dissertation Committee: Dr. Lawrence A. Krissek, Adviser Approved by Dr. E. Scott Bair Dr. Garry D. McKenzie ___________________________________ Dr. Thomas G. Naymik Adviser Graduate Program in Geological Sciences ABSTRACT The importance of unconsolidated deposits is reflected in the extensive use of these materials in Franklin County, Ohio. This study organizes geologic and geotechnical data in a geographic information system (GIS) to better understand the nature of the unconsolidated materials in this area. These data are then utilized to update the bedrock topography maps, evaluate the relationship between the geotechnical data and the diamictons, and to refine the interpretation of the surficial geology of the study area. It was found that discrepancies are common between the surface elevation of geologic borings and the current surface elevation, represented by a digital elevation model (DEM) constructed in this study. It was also shown that there are considerable differences in the surface representation between the DEMs constructed here and DEMs obtained from the USGS. Elevation differences between the DEMs and the surface elevations of geologic borings were confirmed by performing global positioning system surveys at several boring locations. This study concludes that the USGS DEMs do not always accurately represent the current surface in this area, primarily because of land surface modifications by humans. Accurate DEMs are important to surficial mapping, as these efforts often rely on this surface representation for the correct vertical placement of subsurface data. The utilization of DEMs for other purposes is also explored here, showing that the outcome of a particular application can be affected by the DEM utilized. ii The updated bedrock topography maps are used to compare the bedrock drainage patterns, slopes, and aspect to some of the unconsolidated sediments. An evaluation of the geotechnical data is made to assess whether geotechnical properties of the diamictons show consistent variations with depth, and to determine if differences exist between diamictons found on carbonate and clastic bedrock. Standard penetration test values, Atterberg limits, and texture are found to differ somewhat for the diamictons above the different bedrock types, possibly attributed to different source materials for the tills. The diamicton properties in this area suggest they should be re-interpreted as deformation till. Geotechnical data from certain borings also imply that lacustrine deposits are present in several locations in northern Franklin County. iii Dedicated to my family iv ACKNOWLEDGMENTS I first wish to thank my adviser, Dr. Larry Krissek, for his suggestions on selecting a research topic, his many hours devoted to this project, and especially for accepting me as one of his graduate students. This project progressed because of his encouragement and support. Thank you also to my committee members, Drs. E. Scott Bair, Garry McKenzie, and Thomas Naymik. Their encouragement and suggestions were essential to the completion of the research. Much appreciation goes to my employer, Columbus State Community College, who provided me with a job, allowed me to utilize their computers and GPS equipment, and provided financial support during my time at Ohio State. I would like to express my gratitude to many of the employees at the Ohio Department of Natural Resources. Mike Angle and Paul Spahr, of the Division of Water, provided me with encouragement and information that helped in piecing together this project. Several members of the Ohio Geological Survey also greatly assisted me in this research. Jim McDonald provided me with much of the GIS data used in the figures. Mac Swinford provided me with access to ODNR facilities, personnel and data. Rick Pavey gave me many suggestions on the use of GIS for surficial mapping. Scott Brockman, formerly with ODNR, was an endless source of information relative to the v glacial geology of Ohio. I am especially indebted to Rick and Scott for greatly increasing my knowledge of glacial geology. Bob Mergel, of the Civil Engineering Technology program at Columbus State, helped greatly in the GPS portion of the project by providing several days in the field, operation of the equipment, and post-processing of the data. His friendship and many hours donated to this project will always be appreciated. Several employees of Franklin County, Ohio assisted me in the project, but the most important is Tony Stuart. He provided me with access to the data that allowed me to piece together the base map for this project. Several people assisted me in the GIS portion of this project. Among those who put up with my many technical questions are Mike Rock, currently with the city of Albuquerque, and Annie Parsons, with the GIS program at Columbus State. Thank you to my family, for instilling faith and for providing words of encouragement in pursuing this degree. I am indebted to my children, Abbie, Ryan, and Emily, who allowed their dad to be gone while he worked on this project. The most important thank you goes to my wife Suzie. Her endless patience, love, and support allowed me to complete this project and the degree. I will forever be grateful to her. vi VITA 11 October 1968....................................................................................... Born, Toledo, OH 1991......................................... B.A., Geology, University at Buffalo, SUNY, Buffalo, NY Summer 1991.......Geology Field Camp Teaching Assistant, University at Buffalo, SUNY 1991-1993 ..........................Graduate Teaching Assistant, Bowling Green State University Bowling Green, OH Summer 1993................. Intern, Ohio Department of Natural Resources, Geologic Survey Lake Erie Section, Sandusky, OH 1994........................ M.S., Geology, Bowling Green State University, Bowling Green, OH 1993-1995 ................................................Geologist, Metcalf & Eddy, Inc., Columbus, OH 1995-Present ...................... Faculty, Columbus State Community College, Columbus, OH PUBLICATION Bates, J.K., Evans, J.E., 1996. Evaluation of wellhead protection area delineation methods, applied to the municipal well field at Elmore, Ottawa County, Ohio. Ohio Journal of Science, 96, 13-22. FIELDS OF STUDY Major Field: Geological Sciences vii TABLE OF CONTENTS Page Abstract............................................................................................................................... ii Dedication.......................................................................................................................... iv Acknowledgments................................................................................................................v Vita.................................................................................................................................... vii List of Tables ..................................................................................................................... xi List of Figures.................................................................................................................. xiii Chapters: 1. Introduction..............................................................................................................1 1.1 Overview of the Study .......................................................................................1 1.2 Description of the Study Area............................................................................3 1.3 Geology of the Study Area ................................................................................7 2. Review of Previous Studies .....................................................................................9 2.1 Quaternary Period Glaciation in North America ...............................................9 2.2 Glacial Geology of Ohio..................................................................................11 2.3 Geology of Franklin County ............................................................................16 2.3.1 Historical Perspective.......................................................................16 2.3.2 Unconsolidated Deposits..................................................................23 2.3.3 Ancient Drainage/Bedrock Topography...........................................30 2.3.4 Bedrock Geology..............................................................................35 2.4 Geographic Information Systems and Mapping of Unconsolidated Deposits.39 2.5 Geologic Databases..........................................................................................40 3. Methods..................................................................................................................44 3.1 Introduction......................................................................................................44 3.2 Generating the Base Map.................................................................................47 3.2.1 Sources of Surface Elevation Data ...................................................48 3.2.2 Computer Methods Used to Generate Digital Elevation Models .....50