GEOLOGICAL SURVEY OF OHIO J. A. BOWNOCKER, State Geologist FOURTH SERIES, BULLETIN 30 GEOLOGY OF DELAWARE COUNTY By LEWIS G. WESTGATE, Ph.D. PROFESSOR OF GEOLOGY, OHIO WESLEYAN UNIVERSITY • COLUMBUS 192b Published by authority of the Legislature of Ohio, under the supervision of the State Geologist . • ...... Printed by the Ke!ly-Springfidd Printing c, mplny Springfield, Ohio CONTENTS CHAPTER !.-INTRODUCTION Page Location, topography, drainage............................................. 7 Physiographic divisions.... 9 General geological features; preliminary statement............................ IO Bibliography.. 11 Acknowledgments........................................................ 12 CHAPTER IL-BED-ROCK GEOLOGY Introductory statement ..... 13 Age of rocks ............. 16 Geological column ......... 16 Description of formations .. 19 Silurian .............. 19 Monroe formation . .. 19 Devonian ................................ 20 Columbus limestone ................ 20 General statement . .......... 20 Klondike section ................. 23 Other sections....... .................... 23 Base of the Columbus... 26 Top of the Columbus...... ........................... 26 Delaware limestone.. 27 Delaware quarries section ..................................... 27 Other sections .................. 29 Olentangy shale. ......... 31 Ohio shale. ...... 37 General statement.. ............ 37 Life .......................... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 38 Origin of the shale.............. ...................... 39 Mississippian....... ................. 39 Bedford shale. ................... 39 Berea sandstone ..... 41 Sunbury shale ................. 42 Cuyahoga formation ........ 43 The lost interval.. ............... 43 Structural features .. 45 Limestones .... 45 Dolomites ... 49 Concretions. ....... 50 Chert (6int) concretions ................. 51 Limestone concretions in the Olentangy shale. ..... 53 Limestone concretions in the Ohio shale ....... 5-1 Iron sulphide concretions ..... 56 Structural features of the bed-rock... ........ 57 Dip and folding. ..................... 57 Joints; quarrying, weathering, ground water Oow, stream channel deepening. 57 Faults............ ......................................... 60 (3) 4 DELAWARE COUNTY Page Miscellaneous structural features; bedding, cross-bedding, ripple marks, stylolites, cone-in-cone ........................................... 61 Mineralogy. ............ ~ ....................... 63 Geological history ....................................................... 63 Life record. .......................................................... 67 Introductory ........................................................ 67 Vertical distribution of fossils ......................................... 68 Evolution and migration... .................. 68 Character of sediments ........................................... 70 Comparison of Delaware and Columbus faunas.... ....... : ........... 70 Fishes...... ................................................... 71 Common fossils ................ 73 CHAPTER IU.-THE GLACIAL PERIOD Introductory ........... 84 Erosion and removal .... 86 Glaciated surfaces. ................................. 87 Direct ice deposition . .................... 88 The boulder-clay or till. ........................ 88 The clay ....................................................... 89 The boulders. ... 89 The surface form of the glacial drift. ........ 91 The till plain.. ...... 91 The moraines ....................................................... 91 Aq ueo-glacial deposits. .......................... 93 Period of increased stream flow ...........................·. .......• 93 Glacial drainage lines ................................................. 94 Minor spillways ..................................................... 95 The Radnor esker and kame system ........................................• 96 Eskers .............................................................. 96 Karnes ........................................................ 96 Composition ........................................................ 96 Origin...... ..................... 97 Other .kame deposits . ..................................• 99 CHAPTER IV.-STREAM WORK IN POST-GLACIAL TIME Consequent and subsequent drainage ........................................ 100 The bed-rock surface .................................................. 100 Glacial till plain. 101 Pre-glacial valley trenches. • 101 Other buried valleys . 102 The main streams. 102 Introductory.. 102 The Scioto.. 102 The Olentangy. 103 Alum Creek.... ....................................... '. ............ 103 Big Walnut Creek ...................................................• 104 The minor streams.... .... 104 General control.... .............................. 104 Moraine control.. • 105 Trench control ....................................................... 105 Stream-flow survey in Delaware County. 105 TABLE OF CONTENTS 5 Page Special features...... ...... 109 Profiles... ....................... 109 Valley flats and low terracu ................ 110 Terrace remnants... ...... 110 Side-hill gullying and slumpir.g.. .. 111 The cycle of erosion ..................... 111 CHAPTER V.-ECONOMIC GEOLOGY Clays ....................................... 113 Surface glacial clays. ......... 113 Ohio shale ........................... ll3 Bedford shale. ........ 114 Limestone .......... 114 Lime ........... ... 114 Road materials ..... 116 Sand and gravel. .. 118 Building stone ......... ll8 Water supplies ...................... 118 Domestic wells ... 118 Public supplies. 119 Springs .................. 122 Mineral springs ................. 123 Sulphur-saline springs. ....... 123 Temperature of springs ...... 127 Iron springs ................ 127 Lime-carbonate springs .. 128 Oil and gas ................... 129 Oil shale..... ...... 131 Soils ........ 132 ILLUSTRATIONS PLATES Facing page I. A-Quarry of the Scioto Lime and Stone Co. 22 B-Silurian-Devonian unconformity near Warrensburg. II. A-Olentangy shale, Delaware ................................... 32 B-Olentangy shale interbedded in the Ohio. III. A-Ohio shale, Alum Creek ...................................... 38 B-Concretions in Ohio shale. IV. A-Micro-section of Columbus limestone ............................. 52 B-Micro-section of chert. V. A-Small anticline in Delaware limestone. ................... 58 B-Fault in Delaware limestone, Delaware. VI. Monroe and Columbus limestone fossils .......................... 76 VII. Columbus limestone fossils .......... : .......................... 78 VIII. Columbus limestone fossils ..................................... 80 IX. Delaware limestone fossils ...................................... ; 82 6 DELAWARE COUNTY Facing page X. A-Glacial boulder near Stratford.................................... 90 B-Coarse gravel along the Scioto. XL A-Eslrer near Radnor................... 96 B-Section of esker. XII. A-Young valley ................................................... 110 B-Terrace remnant. FIGURES Page 1. Index map. 8 2. Physiographic divisions of Ohio and adjacent territory.. 10 3. Geologic map of Ohio.. 14 4. Columnar section of surface rocks of Delaware County. 17 5. Section of Kilbourne and Jacobs well, Columbus......................... 18 6. Section of Columbus limestone at the quarry (Klondike) of the Scioto Lime and Stone Co.......... ~. 24 7. Section of Delaware limestone in the Delaware quarries..... 28 8. Section of Olenungy shale along Olentangy River just below Delaware. 34 9. Diagrams showing different interpretations of the Devonian rocks according to Grabau and Stauffer.. ... 36 10. Section of chert nodules . 5 I I I. Section of limestone concretion in Olencangy shale. 51 12. Section of limestone concretion in Ohio shale. 51 I3. Section of pyrite concretion in Ohio shale. 51 14. Faulting in quarry at Delaware........................................ 51 15. Stylolite (hackle-tooth) on bedding plane, Columbus limestone............. 62 16. Paleogeographic maps of the eastern half of the United States. 65 17. Map of North American ice sheet............. 85 18. Map of Ohio showing moraines and directions of ice movement. 86 19. Diagram showing formation of moraines ...................... , . 91 20. Formation of eslcer in ice tunnel. 97 21. Section of esker. 97 22. Formation of lea me and es leer.. 98 23. Cross-profile Olentangy Valley below Delaware .......................... 103 24. Cross-profile ravine below Greenwood Lake .............................. 110 25. Cross·profile Mill Creek Valley, East Delaware .......................... 111 26' Ground water conditions in till uplands............................ 119 27. Underground water fl.ow, Delaware County......... 120 28. Mechanical analysis of soil types ...................................... 134 MAPS Facing page I. Geologic map, bed rock . 14 II. Geologic map, surface deposits. 84 CHAPTER I INTRODUCTION Location, Topography, and Drainage Delaware County lies almost exactly at the center of the State of Ohio (Fig. 1), and includes parts of the Delaware, Marengo, Dublin, and Westerville sheets of the topographic map of the United States.1 The county is a part of the nearly level surface of the upper Scioto drainage basin. If we leave out of account, for the moment, the stream valleys, the central and western part of the county is an almost level plain standing about 950 feet above sea level and sloping slightly to the south. Eastward this plain rises to about· 1,200 feet along