CHAPTER III. 



PRE-WISCONSIN DRIFT AND ASSOCIATED DEPOSITS. 



By Frank Leverett. 



LIMIT OF OLACIATION. 



The mapping of the glacial boundary or drift limit in Indiana and Kentucky (see Pis. V 

 and VI) has been brought to its present state through the work of various individuals. In 

 several of the early reports of the Indiana Geological Survey notes on the drift limit are given 

 in connection with more detailed descriptions of the subjacent rock formations. Somewhat 

 later G. F. Wright 1 extended his observations on the limit of glaciation westward from Ohio into 

 Illinois with results sufficiently full to warrant a map setting forth the approximate limit, 

 though he did not, as appears from later studies, give the exact boundary in all districts. The 

 present writer subsequently reconnoitered the border of the drift both in Kentucky and 

 Indiana and presented the results in Monographs XXXVIII and XLI of this Survey. This 

 reconnaissance, it is believed, fixed the limit of glaciation within 1 to 5 miles of its precise 

 position. Owing to the attenuated and patchy condition of the drift near the border he found 

 more precise work difficult. Subsequent to the publication of his reports, Fuller 2 and Clapp 3 

 made a more detailed study of the glacial boundary in southwestern Indiana, determining 

 its character between East White and Wabash rivers more accurately than has been done in 

 any other part of Indiana. 



The border of the well-defined drift deposits enters Indiana from Illinois near the mouth 

 of Wabash River and follows Big Creek and its north or main branch northeastward into north- 

 western Vanderburg County, whence it runs slightly north of east, entering Gibson County 

 south of Haubstadt. It then runs northward to near Francisco and then eastward past Oak- 

 land into Pike County, but within a short distance beyond turns northward and crosses Patoka 

 River and the divide between Patoka and White rivers near the meridian of Petersburg. Here 

 its position is obscured by the deposits of a small glacial lake, Lake Patoka, which covered a 

 considerable area in northeastern Pike and northwestern Dubois counties. The lake extended 

 as far southeast as Jasper, but the ice apparently ended just south of East White River. 



Beyond the area of Lake Patoka the border of the glacial drift crosses to the north side 

 of East White River near Portersville and takes a course slightly east of north to Loogootee, 

 keeping a short distance west of East White River. It then trends northward near the line 

 of Daviess and Martin counties past Burnes and Scotland and into Greene County to Newark, 

 whence, as determined by Siebenthal for the Indiana Survey, it goes northeastward across 

 southeastern Owen and northwestern Monroe counties to the edge of Morgan County. 



Here the glacial boundary is at its northernmost point in Indiana. Its course thence 

 southeastward to Ohio River has been less accurately traced. It turns somewhat abruptly 

 southeastward across the northeast corner of Monroe County to Needmore in Brown County 

 and passes north of Marshall to Mount Liberty in eastern Brown County. Thence it runs 

 southward near Brownstown, Mount Sidney, Little York, Vienna, and Henryville to the Ohio 

 opposite Louisville. It seems to follow the Ohio, without crossing into Kentucky, for several 

 miles above Louisville, and it does not leave the Ohio Valley to strike back into Kentucky until 

 it reaches Bedford, Ky. East of Bedford it remains on the Kentucky side of the Ohio for 

 about 60 miles, or until far past the eastern border of Indiana. It crosses the Ohio into the 

 State of Ohio about 25 miles above Cincinnati. 



i The <dacial boundary in western Pennsylvania, Ohio, Kentucky, Indiana, and Illinois: Bull. U. S. Geol. Survey No. 58, 1S90. 

 ! Fuller, M. L., and Ashley, G. H., Ditney iolio (No. 84), Geol. Atlas U. S., U. S. Geol. Survey, 1902. 

 i Fuller, M. L., and Clapp, F. G., Patoka folio (No. 105), Geol. Atlas U. S., U. S. Geol. Survey, 1904. 



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