68 Proceedings of Indiana Academy of Science 



there is a strong sweep of wind from the southwest — five or six miles 

 without interruption. At present the dunes are from 15 to 20 feet 

 high and rather firmly established. Before vegetation was abundant 

 there must have been very ready movement of the sand. Weather rec- 

 ords at the Terre Haute station tend to verify our statements as to 

 the wind direction. 



Sand deposits have been previously mentioned in this region. Mc- 

 Beth° has a pamphlet on the sand deposits of Vigo County. Shannon" 

 mentions this district as one of the five areas of sand deposition in the 

 state. I have not found any previous suggestion, however, that the 

 dune topography has aff"ected the drainage in any way. 



There is a well record worth attention just south of the present 

 turn in Raccoon Creek. Bits of driftwood and vegetation were found at 

 a depth of 88 feet in connection with loose gravel and silt. This "made 

 land" would, of course, indicate recent filling. 



Summary. — It would seem, therefoi-e, that Raccoon Creek was once 

 a rather large river flowing southwest aci-oss Indiana into the Wabash 

 just above the present site of Terre Haute (figure 1). During glacial 

 times a valley was formed parallel to the Wabash, either (1) by the 

 escape of a glacial stream along the edge of the ice while the Wabash 

 was still covered, (2) by overflow waters of the Wabash, (3) by the 

 ice damming of Raccoon Creek, or (4) by the lowei-ing of the divide 

 between Leatherwood and Raccoon creeks. Of course the valley might 

 have been formed in two or more of these ways. 



In Post-Wisconsin times the Raccoon has been turned into this 

 valley by the filling of its course by wind blown sand. The channel 

 is now obliterated by sand and loess deposits. 



* McBeth, W. A., "Loess and Sand Deposits in Vigo County", Proc. Ind. Acad. Sci., 

 1915. pp. 185-188. 



"Shannon, C. W., "The Sand Areas of Indiana", Proc. Ind. Acad. Sci., 1911, 

 pp. 197-210. 



