This dissertation has been 65-13,226 microfilmed exactly as received F O R D , John Philip, 1930- BEDROCK GEOLOGY IN SOUTHWEST HAMILTON COUNTY, OHIO. The Ohio State University, Ph.D,, 1965 Geology University Microfilms, Inc., Ann Arbor, Michigan BEDROCK GEOLOGY IN SOUTHWEST HAMILTON COUNTY, OHIO DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By John Philip Ford, B. Sc. (Hons.) The Ohio State University 1965 Approved by T Adviser Department of Geology ACKNOWLEDGMENTS This study u/as supported by grant No. GP-479 from the National Science Foundation under the supervision of Professor IYI. P. Uieiss, and by funds from the Bownocksr Fellowship. The author gratefully acknowledges this assistance. He is indebted to Professors M. P. Weiss, W. C. Sweet and G. E. Moore for helpful suggestions and constructive criticism of the manuscript during the period of its preparation. Thanks are due to Mrs. Kathleen Ford and Messrs. Robert H. Osborne and Thomas R. Weaver for assistance freely given in measuring sections. The author is grateful to Professor H. J . Hofmann for interesting discussions on Cincinnatian stratigraphy and for his time spent in comparing data on minor deformational structures. A substantial part of the cost of plates and figures was contributed by the Friends of Orton Hall for which the author expresses his thanks and his indebtedness. ii VITA March 2, 1930 Born - London, England. 1959 ........ B.Sc. (Hons.), University of London, England. 1960-1964 ... Associate Director, Extramural Department, Antioch College, Yellow Springs, Ohio. 1963-1964 ... Research assistant, Department of Geology, The Ohio State University, Columbus, Ohio. 1964-1965 ... Boumocker Fellow, Department of Geology, The Ohio State University, Columbus, Ohio. FIELDS OF STUDY" Major Field: Geology Studies in Stratigraphy: Professors C. A. Lamey, E. IYI. Spieker, R. P. Goldthu/ait, R. L. Bates, Visiting Professor D. A. Busch. Studies in Paleontology: Professor A. La Rocque. Studies in Petrology: Professors M. P. Weiss, G. E. Moore, G. Faure. Studies in Structural Geology: Professor H. J. Pincus. iii Studies in Geomorphologys Professor S. E. White. Studies in Optical Mineralogyt Professor E. G. Ehlers. iv CONTENTS Page 1. Introduction ................................... 1 2. Stratigraphy ................................... 3 Introduction ..... 3 Explanatory statement ................ 3 Field techniques and methods ..... A Kope Formation ..... 0 Lithology ............................... 6 Grand Avenue Member .................... 9 HJesselman Tongue ......... 10 Fairview Formation ....... IB Original definition .................... 15 Fairview Formation redefined ...... 16 North Bend Tongue ................. 21 Supra-Fairview rocks (McMillan in part) ... 22 Miami town Shale ....... 22 Bellevue lithology ............ 29 Corryville lithology ................... 33 Mt. Auburn lithology ................... 34 Nomenclature ........ 36 Use and misuse of Bellevue 38 Bellevue Limestone defined .......... 40 v Page Corryville and lYlt. Auburn ..... 41 McMillan Formation ..................... 41 3. Structure ..... 43 Regional Structure ...... 43 Primary Sedimentary Structures ............ 50 Ripple marks .......... 50 Bedding ............................ 57 Minor Deformational Structures ............ 63 4. Petrography ..... 73 Politic Rocks ..... 73 Carbonate Rocks ................. 75 Classification ............ 75 Newly recognized classes .............. 77 Genetic relationships ................. 83 Hybrid associations ................. 89 5. Paleogeography .......................... 91 Distribution of Limestone Groups ..... 91 Physical History ........................... 92 Appendix Ai Measured Section Locality Register .. 98 Appendix Bi Minor Structure Locality Register ... 99 References Cited .................... 100 vi TABLES Table Page 1 Clastic ratios and bedding Indexes of Kope sections ....... B 2 Clastic-ratio and bedding-index ranges of Grand Avenue Member .............. 9 3 Clastic ratios and bedding indexes of Fairvieui sections .......... 21 4 Ripple measurements! Muddy Creek ..«••••••••• 51 5 Genetic grouping of limestone classes ...... 85 ILLUSTRATIONS Figure Page 1 Type section of Grand Avenue Member ..... 11 2 Type section of UJesselman Tongue ........ 13 3 Grand Avenue Member, North Bend Tongue and Ulesselman Tongue .......... 14 4 Base of Fairvietu Formation at the type section ................................. 17 5 Type section of Fairvieu/ Formation ...... 18 6 Miamitown Shale contacts ................ 19 7 Type section of North Bend Tongue ....... 23 8 Kope-Fairview gradation at cut on Interstate 74 ............................ 24 9 Kope-Fairview gradation at Camp Claybanks 24 10 Isopach map and ripple distribution« Fairview Formation ....................... 25 11 Isopach mapt Miamitown Shale ............. 27 12 Type section of Miamitown Shale .......... 28 13 Typical Bellevue lithology ............... 32 14 Type section of Bellevue Limestone ...... 32 15 Typical Corryville lithology ............. 35 16 Typical supra-Mt. Auburn lithology ...... 37 17 Miamitown Shale - a conspicuous unit in the cliffs at Cincinnati ......... 39 viii Figure Page 18 Structure contour maps base of Fairview Formation ........................ 44 19 Structure contour map t top of Fairvieui Formation .................................... 46 20 Isopach maps UJesselman Tongue, and ripple distributions Kope Formation ...... 47 21 Structure contour maps base of Bellevue Limestone ..................... 48 22 Pararippled limestone on Muddy Creek ••... 52 23 Cross-section of a limestone para- ripple ................................ 55 24 Clean biogenic limestone lentil in upper Kope .................... 58 25 Soft sediment deformation in limestone ... 58 26 Lower surface of channel-filling limestone ..................... 60 27 Cross-section of channel-filling limestone .......................... 60 28 Facies change in uppermost Fairvieui...... 61 29 Reverse fault in upper Kope strata ....... 65 30 Concentric folding and reverse faulting .. 66 31 Concentric folding and low-angle reverse faulting ............................ 66 32 Miniature horsts associated with fold axes 68 ix Figure Page 33 Symmetrically folded bulge ••••••••••••••• 69 34 Class 3C limestone ................. ....... 78 35 Class 3S limestone ....... .............. 81 36 Class 3P limestone ......... ............... 81 Plate I Geologic mapt Southwest Hamilton County. Ohio .............. in pocket II Lithofacies fence diagrami Southwest Hamilton County. Ohio ................... in pocket III Limestone-group distribution diagram: Southwest Hamilton County. Ohio .... in pocket x 1. INTRODUCTION Representative formations which constitute the reference standard of the Upper Ordovician Cincinnatian Series are situated in southwestern Ohio, southeastern Indiana and northern Kentucky. The original lithic divisions of Orton (1873) were discarded by later workers. Classic formation boundaries were established on faunal grounds and the formations, so-called, are time-rock units. Lithologic formation boundaries have not been defined. Consequently lithostratigraphic units have not been mapped in the type area of the Cincinnatian. The purpose of the present study is twofold* first, to identify, define and map type-Cincinnatian rock-units; second, by means of this and all other available geologic evidence to improve our understanding of Cincinnatian stratigraphy and paleogeography. Mapping was completed in the Cincinnati UJest, Addyston, and adjacent areas of the Covington and Burlington 7.5-minute topographic quadrangles, in southwestern Hamilton County, Ohio, an area of approximately 150 square miles. No attempt has been made to map surficial geology. Quaternary deposits, undifferentiated, are denoted in the major valleys by th8 limits of bedrock geology (see map, pi. I). 1 Previous work in the area is extensive, and frequently controversial. An excellent history of Cincinnatian descriptive work was given by Cumings (1922, p. 417-442). The need to distinguish between chrono-, litho-, and bio-3tratigraphic units in the Cincinnatian Series was shown by Gutstadt (1958a, p. 515-521). The extent and the limits of our under­ standing of Cincinnatian stratigraphy were succinctly summarized by U/eiss (1961, p. 645-648). The interested reader should refer to those works for bibliography. 2. STRATIGRAPHY Introduction Explanatory statement. Bedrock exposed at the surface in the area investigated is Edenian, ITIaysvillian and Richmondian in age (see Ufeiss and Norman, 1960a, for development of Ordovician stratigraphic classification in the Cincinnati region). It consists of interbedded limestones, primarily biogenic, and terrigenous clastic rocks consisting essentially of shales and mudstones, with subordinate siltstone and claystone. The term pelitic is used in this paper u/hen general rather than specific reference to terrigenous lithology is intended. Bedrock is divisible into rock units on the basis of observable physical characteristics. The absence of marker beds in the field and the uncertainty involved in tracing beds between outcrops require that we consider first the mass physical characteristics. Locally, fossils impart such striking textural properties to the rocks as to be significant in lithologic differentiation. Ulith this exception, however, neither color nor texture is of any value in identifying and tracing