242 



more particularly about tlie oast end of the Wea Plains along ravines 

 opening into the Big Wea Creek. An exposure 3.5 miles south of LaFay- 

 ette shows a deep layer of false bedded fine sand overlaid by three feet of 

 very dense till, above whieli is ten feet of sand and gravel. This inter- 

 stratilieation of materials appears even more strongly marked along ihe 

 Wild Cat Creeks. At the bridge across South Fork near Monitor are two 

 beds of clay differing in cohir and overlaid liy twenty feet of sand and 

 gravel. Near ryrmont, on the noi'th fork, ten feet of dark alluvial clay 

 appeal's aliove the waters of the creek, above this ten feet of coarse gravel, 

 and aluive this forty feet of gray bowlder cla.v. 



AlHid T()ii<>(ir(iiihji.—T\\e topography of the county about the border of 

 the terrace deposits is interesting and suggestive. A moraine ridge con- 

 taining much gravel, some of it water laid, extends along the entire south 

 side (if tlie Wea Plains. A heavy moraine lies along the north side of the 

 valley frctni Pal tie (Jrouud south, bending away from the river jus'^ above 

 West I.a Fayette. Stream sections in the mass of this moraine show com- 

 pact till as deep as they extend. At the mouth of Indian Creek the upper 

 hundred feet of the bluff is a layer of fine sand resembling the dune sand 

 of Lake ^Michigan, and the sand ridges of northern Indiana. This may be 

 the source of the sand built into the ridges and dunes a mile further up 

 the valley. The bluffs back of T^a Fayette are of till and are possibly a 

 section of the moraine west of the river extending east in the direction of 

 Monitor. 



E.rijliiiKitidii.— An attempt at explanation would revert immediately to 

 the glacial period. The great valley was obstructed somewhere to the 

 west, proliably in the region of the great bend, by an ice sheet moving east 

 or south. This may have been a result of one of the earlier ice invasions. 

 The obstructed valley forming a lake has been Hlled by the deltas of 

 streams flowing into it. The high angle of the layers indicate this. The 

 layers of till represent movements of the ice sheet over the delta plain. 

 These may have lieen minor advances and recessions of the same ice 

 sheet. The material has been assorted out of the drift sheet overlying 

 the basins of the streams traversing the region. The lime cement in the 

 conglomerate is easily explained as being derived from the Niagara lime- 

 stone region lying immediatel.v to the east. 



The problems in detail are of such complexity that any attempt at ex- 

 planation is made with extreme dithdence. There are good reasons for 

 helievinii' that the vallev was over-ridden liv ice fi'om the east and also 



