36 THE ILLINOIS GLACIAL LOBE. 



plain and neighboring sections of the Patoka Valley while the present out- 

 lets along the White and Wabash rivers were blocked by the ice sheet. 



For a few miles north from East White River the exact position of the 

 glacial boundary is difficult to locate, for only scattering pebbles are found 

 along the border. It seems, however, to pass near the village of Alforcls- 

 ville, in Daviess County, and thence to take a northeastward course to the 

 bluff of East White River near Whitfield, in Martin County. The border 

 follows the west bluff of East White River northward past Mount Pleasant 

 to the bend near that village, from which point it continues northward, 

 passing about a mile east of the village of Loogootee. The border then 

 bears west of north and soon enters the western range of sections in Martin 

 County and lies very near the Martin-Daviess county line for 10 or 12 miles. 

 It makes a slight protrusion eastward at the valley of Furse Creek, in 

 northwestern Martin County, and enters Greene County about a mile south- 

 east of the village of Scotland. 



The course of the glacial boundary through Greene, Owen, and Mon- 

 roe counties has been mapped in detail by Mr. C. E. Siebenthal, of the 

 Indiana Geological Survey, and is represented in PI. IX. From near 

 Scotland it has a course slightly east of north to the valley of Plummer's 

 Creek, in sec. 9, T. 6 N., R. 4 W. North of this creek it makes an east- 

 ward protrusion of about 2 miles into a lowland tract known as the Ameri- 

 can Bottom, reaching sec. 36, T. 7 N., R. 4 W. North of this lowland the 

 course of the boundary is west of north to the valley of Richland Creek, 

 in sec. 9, T. 7 N., R. 4 W. It follows the east bluff for about 3 miles and 

 crosses to the west side of the creek in sec. 35, T. 8 N., R. 4 W. It follows 

 nearly the west bluff to sec. 17, T. 8 N., R. 3 W., passing about a mile 

 southeast of the village of Newark. The boundary makes an eastward 

 protrusion of about a mile into Richland Creek Valley in sec. 16, from 

 which the course is northward into Owen County. Entering Owen County 

 in sec. 33, T. 9 N., R. 3 W., the boundary leads northeastward past Free- 

 man post-office and crosses into Monroe County in sec. 6, T. 9 N., R. 2 W. 

 The course continues northeastward through northern Monroe County, the 

 boundary being about 2 miles north of Ellettsville and 1 mile north of 

 Modesto, and coinciding nearly with Indian Creek Valley from mouth to 

 source. From the head waters of Indian Creek, in sec. 3, T. 10 N., R. 1 W., 

 the boundarv leads eastward about 6 miles, near the Monroe-M organ 



