Evidence of a Pre-Mount Simon, Half-Graben in Greene County, Ohio by Reprocessing a Wright State University Seismic Line
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Wright State University CORE Scholar Browse all Theses and Dissertations Theses and Dissertations 2007 Evidence of a Pre-Mount Simon, Half-Graben in Greene County, Ohio by Reprocessing a Wright State University Seismic Line John Sink Wright State University Follow this and additional works at: https://corescholar.libraries.wright.edu/etd_all Part of the Geology Commons Repository Citation Sink, John, "Evidence of a Pre-Mount Simon, Half-Graben in Greene County, Ohio by Reprocessing a Wright State University Seismic Line" (2007). Browse all Theses and Dissertations. 139. https://corescholar.libraries.wright.edu/etd_all/139 This Thesis is brought to you for free and open access by the Theses and Dissertations at CORE Scholar. It has been accepted for inclusion in Browse all Theses and Dissertations by an authorized administrator of CORE Scholar. For more information, please contact [email protected]. EVIDENCE OF A PRE-MOUNT SIMON, HALF-GRABEN IN GREENE COUNTY, OHIO BY REPROCESSIING A WRIGHT STATE UNIVERSITY SEISMIC LINE A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science By JOHN ESTEN SINK B.S., Michigan State University, 2005 B.A., Michigan State University, 2005 2007 Wright State University WRIGHT STATE UNIVERSITY SCHOOL OF GRADUATE STUDIES June 6 th , 2007 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY John E. Sink ENTITLED Evidence of a Pre-Mount Simon, Half- Graben Basin in Greene County, Ohio by Reprocessing a Wright State University Seismic Line . BE ACCEPTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Science. ________________________ Ernest Hauser, Ph.D. Thesis Director ________________________ Allen Burton, Ph.D. Department Chair Committee on Final Examination __________________________ Ernest Hauser, Ph.D. __________________________ Paul Wolfe, Ph.D. __________________________ Cindy Carney, Ph.D. __________________________ Joseph F. Thomas, Jr., Ph.D. Dean, School of Graduate Studies ABSTRACT Sink, John Esten. M.S., Department of Geological Sciences, Wright State University, 2007. Evidence of a Pre-Mount Simon, Half-Graben Basin in Greene County, Ohio by Reprocessing a Wright State University Seismic Line. The reprocessing of the WSU2002 seismic line indicates the presence of a Precambrian half-graben. Also observed through this reprocessing is the possible presence of Paleozoic structures. Although Paleozoic features have been interpreted, variations in glacial drift thickness evidenced by glacial drift maps also may have contributed to a lower quality of stacked section in comparison to other seismic lines. WSU2002 was originally processed by Lauren Geophysical. The Lauren processing resulted in an image that was of much lower quality than corresponding seismic lines. The Lauren Geophysical processed section revealed many horizontal Paleozoic reflections, with no prominent reflectors beneath the Paleozoic. This prompted a study to be done to reprocess the data and determine if other reflections could be found. As a result of the processing undertaken in this study new reflectors have been found beneath the Paleozoic reflections. There are multiple interpretations of the sub- Paleozoic reflections which lead to a half-graben interpretation. Also new in this study is topography in the usually flat lying Paleozoic reflections. A low coherency in reflections is assumed to be the result of glacial drift thickness variations. At one point in the lower Paleozoic reflections is interpreted above a reactivated fault. This anticline could also be the result of variations in glacial drift. iii TABLE OF CONTENTS Page 1.0 INTRODUCTION 1.1 Background…………………………………………………………….. 1 1.2 Geology………………………………………………………………… 7 2.0 METHODS 2.1 Location………………………………………………………………... 12 2.2 Acquisition……………………………………………………………... 14 2.3 Seismic Processing……………………………………………………...17 2.3.1 Raw Data Input………………………………………………… 17 2.3.2 Combine Raw Data Sets……………………………………….. 17 2.3.3 File Editing……………………………………………….......... 21 2.3.4 Geometry………………………………………………………..21 2.3.5 Trace Editing…………………………………………………… 21 2.3.6 Top Mute……………………………………………………….. 21 2.3.7 Bandpass Filter………………………………………………….25 2.3.8 Automatic Gain Control………………………………………... 25 2.3.9 Elevation Statics………………………………………………...25 2.3.10 FK Filter/Analysis……………………………………………… 28 2.3.11 CMP sort……………………………………………………….. 28 2.3.12 Constant Velocity Stacks………………………………………. 28 2.3.13 NMO Correction……………………………………………….. 31 2.3.14 Residual Statics………………………………………………… 31 2.3.15 Stack……………………………………………………………. 31 iv 3.0 DISCUSSION………………………………………………………………….. 34 4.0 CONCLUSIONS……...……………………………………………………….. 47 5.0 REFERENCES………………………………………………………………… 48 v LIST OF FIGURES Figure Page 1. Cincinnati Arch Consortium seismic line……………………………………… 2 2. Stratigraphic section cored during the drilling of DGS 2627………………….. 3 3. Basement provinces of the Midcontinent of North America…………………... 5 4. Magnetic anomalies of Ohio showing the location of the Grenville Front…………………………………………………………...6 5. Structure contour map of the Precambrian surface in Ohio……………………. 8 6. Development of the East Continent Rift Basin in western Ohio………………. 9 7. County map of Ohio showing the location of the city of Xenia and a Road map showing location of WSU 2002……………………………… 13 8. Example of how a vibroseis truck rolls into a seismic line…………………….. 15 9. Example of how a vibroseis truck rolls off of a seismic line…………………... 16 10. WSU2002A channels 1-60…………………………………………………….. 18 11. WSU2002B channels 61-120…………………………………………………... 19 12. Combined 120 channel raw shot gather………………………………………... 20 13. Bad file within WSU 2002……………………………………………………... 22 14. Geometry of WSU2002 seismic line, entered in UTM’s………………………. 23 15. Traces selected to be zeroed…………………………………………………… 24 16. Shot gather with a top mute applied above the refracted wave………………... 26 17. Effects of an Ormsby bandpass filter on frequency……………………………. 27 18. Example of an FK filter used on a shot gather…………………………………. 29 19. Common mid-point sort………………………………………………………... 30 20. Processing flow chart used to process WSU2002……………………………… 33 vi 21. Interpreted Lauren Geophysical processing……………………………………. 38 22. Interpreted Cincinnati Arch Consortium and WSU seismic lines……………... 39 23. Interpreted Selma Basin seismic section……………………………………….. 40 24. Interpretation of WSU2002 with a non-reflective east dipping fault bounding one side of a Middle Run basin………………………………... 41 25. Interpreted WSU2002 with dipping reflectors representing a fault……………. 42 25. Crossover in geometry of stations………………………………………………45 26. Glacial drift map with locations of seismic lines………………………………. 46 vii LIST OF PLATES Plate 1. WSU2002 processed by Lauren Geophysical. 2. WSU2002 processed in this study. viii ACKNOWLEDGEMENTS “The task ahead of us is never as great as the power behind us.” -Ralph Waldo Emerson I would like to thank my advisor, Dr. Ernest Hauser, whose advice and knowledge were instrumental in the completion of this research. Thanks to all my other committee members, Dr. Cindy Carney, and Dr. Paul Wolfe for their time and help. Special thanks to Dr. Doyle Watts, for if it were not for his help, I would never have learned how to use Promax. To Katharine Owen who has also put many hours reading and re-reading my thesis. Also to my friends, Peter Phillips and Gregory Capriotti for helping me make it through the long weekends. To my parents, Doug and Connie Sink and my brother Steven Sink for always being there for me, and giving me endless amounts of guidance. To Starbucks for always having caffeine available, and to all those I have failed to mention, thank you. Cheers. ix 1.0. INTRODUCTION 1.1 Background In the 1990’s, after the discovery of the Precambrian Middle Run Formation in Warren County and the associated seismic line (Figure 1), Wright State University (WSU) has collected a series of short industry-scale seismic reflection lines in southwestern Ohio. One of the goals of these seismic lines was to better map the distribution and origin of the Middle Run strata lying just west of the Grenville Front. The WSU seismic line collected in 2002, hereafter named WSU2002, is the most recent of these WSU seismic lines. Although WSU2002 was originally processed gratis by Lauren Geophysical to professional standards, the quality of the resulting stacked section was lower than that of prior seismic lines. As a result, the 2002 line is here targeted for reprocessing to try to improve the image and to understand the cause of its lower quality. The Middle Run Formation is a red lithic arenite, discovered during the drilling of core hole DGS 2627 in Warren County, Ohio by the Department of Natural Resources, Division of Geological Survey (DGS). Prior to the drilling of core hole DGS 2627, project geologists involved believed that the Mount Simon Sandstone (Upper Cambrian) rested unconformably upon the Precambrian crystalline basement. The continuous core obtained included the top of the Drakes Formation (Upper Ordovician) through the Mount Simon Sandstone, however below the Mount Simon a new sedimentary unit was discovered (Figure 2). This unit was named the Middle Run Formation (Shrake, 1990). The unexpected discovery of the Middle Run Formation sparked further investigation, and seismic lines have sought to clarify its depositional setting. 1 Figure 1. Cincinnati Arch Consortium seismic line associated with the DGS2627 line (Shrake, 1991). 2 Figure 2. Stratigraphic section cored during the drilling of DGS 2627 (Shrake