WABASH MORAINE. 545 



The cause of this extensive prairie tract in the midst of the forests of 

 Ohio is an interesting problem, but a solution has not yet been found. 

 It is popularly supposed that these treeless plains were once covered by a 

 lake ; but they have not the horizontal surface which a lake bottom should 

 have. Instead the surface rises from west to east at the rate of 10 feet or 

 more per mile, the altitude near the Scioto being 920 feet, while on the 

 eastern borders of the 23rairie, 12 to 15 miles eastward, it is luUy 1,050 feet. 

 The prairie extends north beyond the plain, occupying a portion of the 

 moi'aine that follows the divide between the Scioto and Sandusky rivers. 

 Its altitude decreases toward the north, until near Upper Sandusky it is but 

 850 feet. No well-defined lacustrine formations, such as beaches or sand 

 deposits, were observed on its surface. The soil has fewer pebbles than 

 ordinaril}'' characterizes the till plains, but it is not a pebbleless clay. It 

 seems to be a glacial deposit, and the presence of surface bowlders of 

 Archean rocks makes it evident that not much deposition has occurred since 

 the ice sheet withdrew, else they would have been covered. 



SECTION III. MORAIlsrES OF THE IVIAUMEE LOBE. 



<- WABASH MORAINE. 



The portion of this moraine traversing western Ohio was traced some 

 years ago by N. H. Winchell, and by him was given the name Wabash ^ 

 More recently Dryer has traced much of the portion in Indiana.^ The 

 writer's observations cover the interval between the portions thus studied, 

 and also extend the entire length of the moraine in these States. 



DISTRIBUTION. 



The Wabash moraine does not connect with the interlobate morainic 

 tract of Logan and southern Hardin counties, Ohio, but, as indicated in 

 Pis. XI and XIII, may be readily traced from the highlands east of the 

 Scioto Basin westward across that basin into the region occupied by the 

 Maumee-Miami lobe. Farther east it is closely associated with a later 

 moraine (the Fort Wayne). The combined belt, however, is traceable east- 

 ward into an interlobate moraine occupying the highlands west of the Orand 

 River Basin, beyond which it has not been recognized. 



iProc. Am. Assoc. Adv. Sci., 1872, pp. 166-167. 



2 Sixteenth Ann. Eept. Geol. Survey Indiana, 1888, pp. 119-122. 



MON XLI 35 



