BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL. 51. PP. 1337-1358. 1 PL.. 9 FIGS. SEPTEMBER 1. 1940 NEW EVIDENCE FOR AN ILLINOIAN GLACIAL BOUNDARY IN NORTHEASTERN OHIO BY H. ANDREW IRELAND CONTENTS Page Abstract....................................................................................................................................... 1337 Introduction and acknowledgments.................................................................................... 1339 Pre-Illinoian history................................................................................................................. 1340 General statement............................................................................................................ 1340 Preglacial history.............................................................................................................. 1340 Pre-Illinoian ice sheet..................................................................................................... 1341 Deep Stage period........................................................................................................... 1341 Description of the Port Washington deposit.................................................................... 1345 Illinoian outwash in eastern and central Ohio................................................................. 1349 Illinoian slack-water silt......................................................................................................... 1351 Pleistocene erosion in the Tuscarawas Valley................................................................... 1352 Illinoian drainage...................................................................................................................... 1353 Postulated Illinoian boundary in northeastern Ohio...................................................... 1354 Conclusions................................................................................................................................. 1355 Works to which reference is made....................................................................................... 1357 ILLUSTRATIONS Figure Page 1. Location map for eastern and northeastern portion of Ohio................................ 1338 2. Topographic map of southeast corner of Newcomerstown, Ohio, Quadrangle. 1340 3. Probable preglacial drainage of Port Washington area......................................... 1342 4. Present drainage of Port Washington area................................................................ 1342 5. Deep Stage drainage channels....................................................................................... 1342 6. Revision of Deep Stage drainage channels based on additional bedrock ele­ vations .................................................................................................................................. 1342 7. Detailed map of glacial deposits in Port Washington area................................... 1344 8. Projected profile of physiographic relations along Glasgow Valley and across Tuscarawas River.............................................................................................................. 1346 9. Glacial features of eastern Ohio and adjacent portion of Pennsylvania........... 1348 Plate Facing page 1. Illinoian gravel terraces and Glasgow Valley............................................................ 1337 ABSTRACT The discovery of high-level Illinoian outwash gravel in the Tuscarawas River valley near Port Washington, Ohio, proves that Illinoian ice existed in the headwaters of the present valley. The deposit lies 35 miles east of the outwash from the Illinoian drift in central Ohio. The gravel is 90 feet above the Wisconsin outwash (1337) Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/51/9/1337/3415906/BUL51_9-1337.pdf by guest on 02 October 2021 1338 H. A. IRELAND----ILLINOIAN GLACIAL BOUNDARY IN OHIO terraces and was deposited in a bypass of the main Illinoian drainage channel so that it was protected from removal when Wisconsin outflowing water passed down the Tuscarawas Valley. A lower gravel terrace 30 feet above the Wisconsin level is considered late Illinoian. Evidence for identifying the gravel as Illinoian, conditions F ig u re 1.—Location map for eastern and northeastern portion of Ohio during that epoch, and a discussion of the related preglacial and Pleistocene physiographic history are presented. Evidence is given to show that the Atlantic- Gulf divide at Port Washington was incised in pre-IUinoian time instead of later. The existence of Illinoian ice as far south as Shreve, Ohio, the presence of the Illinoian gravel at Magnolia, Ohio, and the gravel at Port Washington, Ohio, make Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/51/9/1337/3415906/BUL51_9-1337.pdf by guest on 02 October 2021 BULL. GEOL. SOC. AM., VOL. 51 IRELAND, PL. 1 vm. F ig u r e 1. V i e w o f I l l in o ia n G r a v e l T e r r a c e On northwest side of lower segment of Glasgow Valley. F ig u r e 2 . L o o k in c . S o u t h w e s t D o w n G l a s g o w V a l l e y The Illinoian terrace is at crest of the divide near house. Main valley of the Tuscarawas is in the bac kground. F i g u r e 3 . M id d l e S e g m e n t o f G l a s g o w V a l l e y Looking northeast up the valley. Level of Parker strath is saddle beyond the village. Wisconsin slack-water silt is beneath church at the right. ILLINOIAN GRAVEL TERRACES AND GLASGOW VALLEY Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/51/9/1337/3415906/BUL51_9-1337.pdf by guest on 02 October 2021 Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/51/9/1337/3415906/BUL51_9-1337.pdf by guest on 02 October 2021 ABSTRACT 1339 it possible to connect more accurately the Illinoian drift of the Scioto lobe in cen­ tral Ohio with that of northwestern Pennsylvania. The existence of Illinoian ice across northeastern Ohio disproves statements that drainage of the upper Ohio basin during Illinoian time was through the Lake Erie basin. INTRODUCTION AND ACKNOWLEDGMENTS Work in eastern Ohio discloses an undescribed deposit of Illinoian out- wash gravel in the Tuscarawas River Valley near Port Washington, 35 miles east of Illinoian outwash material at the glacial boundary. Known drift of the Illinoian Scioto lobe lies in central Ohio east of the Wisconsin Scioto lobe in a band about 2 to 15 miles wide from near Perrysville south­ ward to Lancaster, Ohio, from where it can be traced almost continuously into southern and southwestern Ohio (Figs. 1, 9). Most of the Illinoian drift is in basins which drain eastward to the Muskingum River. The Tuscarawas River drains westward and joins the Walhonding at Coshoc­ ton to form the Muskingum River. The Tuscarawas Valley has no con­ nection with known Illinoian drift, and the presence of the outwash gravel in the valley proves that Illinoian ice entered the headwaters of the valley and indicates that the ice border was probably not far north of the Wis­ consin drift boundary (Fig. 9). The outwash deposit is located in the southeast portion of the New- comerstown, Ohio, Quadrangle, about 2 miles east of Newcomerstown along U. S. Highway 36 where it leaves the main valley of the Tuscarawas River and turns northeast up a small tributary valley. (See arrow on Figure 2.) The road crosses a low divide, which forms the crest of the Illi­ noian terrace, and re-enters the main valley along a small tributary about 2 miles southwest of Port Washington. Starting about one mile west of Port Washington is a valley 3 miles long trending southwest parallel to the Tuscarawas Valley. During preglacial time the valley was a single drainage basin which drained into what later became the Tuscarawas Valley (Fig. 3). The village of Glasgow is near the center of the valley which is designated as the Glasgow preglacial valley. Stream piracy divided Glasgow Valley into three drainage segments—lower, middle, and upper; these are marked a, b, and c respectively on Figure 4. The effect of piracy is very important as it provided a bypass valley as a side channel away from the main Illinoian channel in which outwash material was deposited. The material was protected in the bypass from removal by Wisconsin outflow water. The writer wishes to express appreciation for the comments, excellent suggestions, and valued criticism given by L. G. Westgate of Ohio Wes­ leyan University, W. S. Cole of Ohio State University, G. W. White of the University of New Hampshire, and C. F. S. Sharpe and C. W. Thorn- thwaite of the Soil Conservation Service, all of whom read the manuscript. Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/51/9/1337/3415906/BUL51_9-1337.pdf by guest on 02 October 2021 1340 H. A. IRELAND----ILLINOIAN GLACIAL BOUNDARY IN OHIO PRE -ILLIN OIAN HISTORY GENERAL STATEMENT Before the description and the evidence for the age of the Illinoian out­ wash at Port Washington are given, it is desirable to present the pre- F ig u re 2.— Topographic map of southeast corner of Newcomerstown, Ohio, Quadrangle, showing the vicinity of Port Washington Illinoian physiographic history of the surrounding region and to mention especially the drainage changes of the Deep Stage period. PREGLACIAL HISTORY Port Washington is exactly on the preglacial Atlantic-Gulf divide (Cof­ fey, 1930). The drainage northeast of the divide flowed northward up Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/51/9/1337/3415906/BUL51_9-1337.pdf