128 PLEISTOCENE OF INDIANA AND MICHIGAN. 



Section of drift in Ashby well at Mount Ayer, Ind. 



Feet. 



Till, yellow 10 



Sand, blue 20 



Till, blue 90 



Shale, blue 20 



Rock, bard, flinty. 



140 



Two wells at Surrey that enter rock at 90 feet are mainly through till. Several borings 2 or 3 

 miles north of Surrey strike rock at 80 or 90 feet. On the crest of the moraine southeast of 

 Surrey at Charles Coen's, in sec. 12, T. 29 N., K. 7 W., a well strikes rock at 192 feet and there 

 obtains water. At William Nowel's, in the same section, a well strikes rock at 140 feet and 

 obtains water at 162 feet. In both wells the drift is mainly till. 



A well on the moraine southwest of Medaryville, hi sec. 13, T. 30 N., R. 5 W., penetrates 

 102 feet of drift, mainly blue till; another in the same section penetrates 80 feet. A well at 

 Mr. Osborne's, hi sec. 1 of the same township, has 126 feet of drift, and one at Mr. Rayburn's, in 

 sec. 2, has 118 feet. A well at the tile factory hi Medaryville passed through 92 feet of drift 

 and obtained water from the rock at 115 feet. A prospect boring for gas shows the drift at 

 North Judson to be 198 feet thick. 



From North Judson a heavy body of drift extends eastward across northern Indiana. The 

 rock surface appears to be somewhat lower along the line of this moraine than a few miles south 

 of it, for the drift is very thin in southwestern Pulaski and hi much of southern Jasper and Newton 

 counties. The rock also appears to be higher north of the moraine in a small tract near the 

 corners of Starke, Jasper, Porter, and Laporte counties, several oil wells having entered it at 

 50 feet or less. 



SAND OF KANKAKEE-TIPPECANOE AREA. 



The sand of the Kankakee-Tippecanoe area was discussed in Monograph NXXVIII as a 

 deposit of Lake Kankakee, though it was pohited out that the "lake" seemed to consist not of 

 any general body of water, but merely of small shallow marshlike areas not very different from 

 those of the present Kankakee Marsh. It was suggested by Chamberlin * that the great accu- 

 mulations of sand are probably referable to outwash from adjacent ice lobes, the Lake Michigan 

 lobe bordering the area on the north and the Erie-Saginaw lobe on the east. Subsequent 

 investigations have sustained this idea and have brought out evidence that points to a north- 

 ward and eastward enlargement of the sand area during the recession of the ice lobe. The 

 existence of certain low-lying tracts strewn with bowlders and nearly free from sand amid 

 bordering higher sand-covered areas suggests that patches of stagnant ice persisted while the 

 sand was being laid down. By the time the stagnant ice had disappeared the deposition of 

 the sand seems to have been practically completed hi much of the area south of the Kankakee 

 Marsh. 



If the deposition of the sand was progressive, it probably began along a belt which runs 

 westward for 20 miles from Monticello through White and northern Benton comities, nearly 

 parallel with the Nebo-Gilboa ridge and distant from it scarcely 3 miles. It has in places the 

 narrow, definitely ridged form of a shore line, behig 100 to 200 yards in width and 10 feet or 

 less in height, but it varies in altitude in a manner inconsistent with its being a shore feature. 

 It ranges from 675 up to fully 750 feet above tide, rising from Monticello westward to about 

 the meridian of Goodland and beyond that point descendhig to a western terminus near Kentland 

 nearly as low as its beginning at Monticello. Its parallelism, to the Nebo-Gilboa ridge suggests 

 that it is an ice-border feature formed probably in a manner similar to an outwash apron. The 

 higher land to the south would prevent the spread of the sandy outwash beyond the immediate 

 edge of the ice, and thus account for the narrowness of the sand belt. Some of the ridging may 

 have been produced by wind action. 



On theoretical grounds it seems probable that ponded conditions prevailed in the district 

 south of the Marseilles morainic system during its development. The basin now drahied north- 



i Preliminary paper on the terminal moraine of the second glacial epoch: Third Ann. Rept. U.S. Geol. Survey, 1883, p. 330. 



