STATE OF OHIO Bob Taft, Governor DEPARTMENT OF NATURAL RESOURCES Samuel W. Speck, Director DIVISION OF GEOLOGICAL SURVEY Thomas M. Berg, Chief STRUCTURE CONTOUR MAP ON THE PRECAMBRIAN UNCONFORMITY SURFACE IN OHIO AND RELATED BASEMENT FEATURES A description to accompany Division of Geological Survey Map PG-23 by Mark T. Baranoski Columbus 2002 DIVISION OF GEOLOGICAL SURVEY 4383 FOUNTAIN SQUARE DRIVE COLUMBUS, OHIO 43224-1362 (614) 265-6576 (614) 447-1918 (FAX) e-mail: [email protected] World Wide Web: http://www.ohiodnr.com/geosurvey/ OHIO GEOLOGY ADVISORY COUNCIL Ms. F. Lynn Kantner, representing At-Large Citizens Mr. David A. Wilder, representing Coal Mr. C. Robert Lennertz, representing Environmental Geology Dr. Mark R. Boardman, representing Higher Education Dr. Robert W. Ritzi, Jr., representing Hydrogeology Mr. Ronald M. Tipton, representing Industrial Minerals Mr. William M. Rike, representing Oil and Gas SCIENTIFIC AND TECHNICAL STAFF OF THE DIVISION OF GEOLOGICAL SURVEY ADMINISTRATION (614) 265-6988 Thomas M. Berg, MS, State Geologist and Division Chief Dennis N. Hull, MS, Assistant State Geologist and Assistant Division Chief Michael C. Hansen, PhD, Senior Geologist, Ohio Geology Editor, and Geohazards Officer Betty R. Lewis, Fiscal Officer James M. Patterson, Account Clerk Sharon L. Stone, AD, Executive Secretary GEOLOGIC MAPPING GROUP (614) 265-6473 LAKE ERIE GEOLOGY GROUP (419) 626-4296, (419) 626-8767 (FAX) Edward Mac Swinford, MS, Geologist Supervisor Richard R. Pavey, MS, Surficial Mapping Administrator Constance J. Livchak, MS, Geologist Supervisor C. Scott Brockman, MS, Geologist Danielle A. Foye, BS, Geologist Glenn E. Larsen, MS, Geologist Jonathan A. Fuller, MS, Geologist Gregory A. Schumacher, MS, Geologist Donald E. Guy, Jr., MS, Senior Geologist Douglas L. Shrake, MS, Geologist Dale L. Liebenthal, Operations Officer & Research Vessel Operator Kim E. Vorbau, BS, Geologist CARTOGRAPHY & EDITING GROUP (614) 265-6593 COAL & INDUSTRIAL MINERALS GROUP (614) 265-6594 Edward V. Kuehnle, BA, Cartographer Supervisor Douglas L. Crowell, MS, Geologist Supervisor Merrianne Hackathorn, MS, Geologist and Editor Ronald G. Rea, MS, Geologist and Sample Repository Manager Donovan M. Powers, BA, GIMS Specialist Mark E. Wolfe, BS, Geologist Lisa Van Doren, BA, Electronic Designer PETROLEUM GEOLOGY GROUP (614) 265-6598 GEOLOGIC RECORDS CENTER (614) 265-6585 Lawrence H. Wickstrom, MS, Geologist Supervisor Garry E. Yates, NZCS, Supervisor Mark T. Baranoski, MS, Geologist Madge R. Fitak, BS, Office Assistant James McDonald, MS, Geologist Sharon E. Lundy, Office Assistant Ronald A. Riley, MS, Geologist Ernie R. Slucher, MS, Geologist Joseph G. Wells, MS, Database Administrator An Equal Opportunity Employer - M/F/H recycled paper STATE OF OHIO Bob Taft, Governor DEPARTMENT OF NATURAL RESOURCES Samuel W. Speck, Director DIVISION OF GEOLOGICAL SURVEY Thomas M. Berg, Chief STRUCTURE CONTOUR MAP ON THE PRECAMBRIAN UNCONFORMITY SURFACE IN OHIO AND RELATED BASEMENT FEATURES A description to accompany Division of Geological Survey Map PG-23 by Mark T. Baranoski Columbus 2002 i Typesetting and layout: Lisa Van Doren ii CONTENTS Abstract ....................................................................................................................................... 1 Introduction ................................................................................................................................ 1 Geologic setting........................................................................................................................... 1 Previous mapping of the Precambrian surface in Ohio ............................................................ 3 Methods ....................................................................................................................................... 4 Discussion ................................................................................................................................... 5 Acknowledgments ....................................................................................................................... 5 References cited .......................................................................................................................... 6 Appendix A.—Regional structural features in the Precambrian basement of Ohio ............... 11 Appendix B.—Well data for control points on Map PG-23 ....................................................... 14 Appendix C.—Seismic reflection profiles shown on Map PG-23 .............................................. 18 FIGURES 1. Major deep “pre-Ordovician” structural features ................................................................... 2 2. Major shallow “post-Cambrian” structural features .............................................................. 2 CLICK HERE FOR MAP PG-23 iii iv STRUCTURE CONTOUR MAP ON THE PRECAMBRIAN UNCONFORMITY SURFACE IN OHIO STRUCTURE CONTOUR MAP ON THE PRECAMBRIAN UNCONFORMITY SURFACE IN OHIO AND RELATED BASEMENT FEATURES A description to accompany Division of Geological Survey Map PG-23 by Mark T. Baranoski ABSTRACT GEOLOGIC SETTING The Precambrian unconformity surface in Ohio is de- Structural features in Ohio are known primarily fined in eastern Ohio by the top of Grenville Province meta- from the mapping of bedrock-geology contacts and the morphic and igneous rocks and in western Ohio by the top interpretation of oil and gas drilling data. Although a of East Continent Rift Basin sedimentary and volcanic rocks detailed discussion of all features is beyond the scope and Granite-Rhyolite Province igneous rocks. Map PG-23 of this report, major features are briefly discussed to was generated by a combination of computer-assisted and manual methods using well data, seismic data, and fault show that the underpinning Precambrian basement information for control. The dominant structural feature on affected deposition and structure of overlying Paleo- the map is a north-south-trending break in slope, or increase zoic sedimentary rocks. Bass (1960), and subsequently in eastward dip, that extends from Ottawa County to Brown many others, interpreted a boundary in Ohio, referred County and defines the western limit of the Appalachian to as the Grenville Front or Grenville Front Tectonic Basin. This ridgelike structural feature is coincident with a Zone, that separates the Grenville Province from the zone of higher frequency magnetic data. The emplacement older Granite-Rhyolite Province (see inset on Map and subsequent deep erosion of Grenville Province rocks PG-23). Summerson (1962) recognized the coincidence profoundly affected Appalachian Basin architecture. Other of a break in slope on the top of the Precambrian sur- major structural features that can be recognized on the map include the Bowling Green Fault System, the Findlay Arch, face with variations in Precambrian lithology noted and the Ohio Platform separating the Appalachian, Illinois, by McCormick (1961) and with trends of contours on and Michigan Basins. gravity maps of Heiskanen and Uotila (1956). Calvert (1974) speculated that Grenville Province metasedi- INTRODUCTION mentary rocks were less resistant to erosion than the igneous rocks to the west, thus resulting in a resis- More than 30 years have elapsed since the Ohio tant ridge along the province boundary. Division of Geological Survey (ODGS) last published Later workers, using regional gravity and mag- a statewide interpretation of the Precambrian netic data, speculated on the presence of various Pre- unconformity surface (Owens, 1967). The large num- cambrian rifts in western Ohio (McGuire and Howell, ber of wells drilled to the Precambrian since Owens’ 1963; Lidiak and Zietz, 1976; Halls, 1978; Keller and (1967) map, including two continuously cored holes others, 1982, 1983; Cable and Beardsley, 1984; drilled by the ODGS in Seneca County (Wickstrom Denison and others, 1984; Black, 1986; Hinze and oth- and others, 1985) and Warren County (Shrake and ers, 1987; Lucius and von Frese, 1988). The discovery others, 1990), have greatly increased our knowledge (Shrake and others, 1990) of the Middle Run Forma- of Precambrian geology. Along with new knowledge tion, a thick pre-Mount Simon sedimentary unit, in come new questions. This report and the accompany- Warren County provided impetus to re-examine Pre- ing map (PG-23) do not attempt to interpret Precam- cambrian well records of the region. Drahovzal and brian geologic history nor resolve questions surround- others (1992) used well control and geophysical data ing this complex subject. This report does present to interpret a regional Precambrian rift system, which structural data currently available for the Precam- they named the East Continent Rift Basin; this rift brian surface in Ohio, and the map shows the inter- basin postdated the Granite-Rhyolite Province and preted Precambrian unconformity surface. Appendix predated the Grenville Province. Drahovzal and oth- A lists the names of faults and other structural fea- ers (1992) estimated that the East Continent Rift tures thought to be related to movement and/or bound- Basin contains sequences of sedimentary and volcan- aries in the Precambrian basement. Appendix B lists ic rocks greater than 20,000 feet thick in areas adja- data for wells used in compiling Map PG-23. Appen- cent to the Grenville Front. Some workers have de- dix C lists the seismic lines shown on Map PG-23. bated the existence of a Precambrian rift basin 1 STRUCTURE CONTOUR MAP ON THE PRECAMBRIAN