240 



valley at a height of one hundred to one hundred and fifty feet above 

 the present river channel. 



The Pir-r/1(uial TaUrij.—As the stream flows on a valley floor of rock at 

 Delphi, eighteen miles above LaFayette, and again at Black Rock, at the 

 west line of the county, fourteen miles below, the nature of the intervening 

 depression. Its shaiie, direction and extent have been and are still matters 

 of interesting speculation. It is probably a section of the valley of the pre- 

 glacial Wabash. This valley bottom is sixty or eighty feet above the bot- 

 tom of the filled valley at Terre Haute and the two sections possibly are 

 connected by a buried valley somewhere near the present stream line. 



There are signs that its former course was north of its present course 

 from the west line of Tippecanoe County into the immense pre-glacial 

 valley of Kickapoo Creek, opening into the Wabash Valley at Attica. 

 Gates' Pond, a traditionally bottomless kettle hole pond or lake, about two 

 miles northwest of Independence, Warren County, is a good link in the 

 evidence of such a former course. 



The abrupt drop of two hundred feet from the valley bottom at Delphi 

 to the rock floor beneath LaFayette indicates that the part of the stream 

 above Delphi is not in the old valley. The north fork of Wild Cat Greek 

 perhaps more nearly represents the pre-glacial drainage line. The little 

 creeks between this creelc and the Wabash show rock in their channels, 

 while Wild Cat does not cut down to bed-rock at any place in Tippecanoe 

 County, so far as I know, although its valley is one hundred feet or more 

 in depth as far up as the county line. 



Rock outcrops in the bed of Indian Creek near Porter's Station, in the 

 bed of Little Wea Creek at the Monon Railway crossing and along Flint 

 Creek for four or five miles above its mouth. 



Borings are few and not many are deep. A well driven forty or fifty 

 feet below the bed of the Big Wea Creek, where it is crossed by the mo- 

 raine about five miles south of LaFayette, passed through gravel hardpan 

 and into quicksand, producing a constant flow of water. 



Materials and Struetnre of the Terraces.— The terraces and the whole 

 valley region are composed of sand, gravel and bowlders with interposed 

 beds of clay. The whole deposit is of great depth, in places as much as 

 three hundred or four hundred feet. The channel of the river at LaFayette 

 is two hundred feet below tlie general surface of the county and one hun- 

 dred and fifty feet above the bed-rock, giving total depth of three hun- 

 dred and fifty feet of deposits- 



