278 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



gravel deposits are to be seen in the district south of the outer Wisconsin 

 moraine was noted by Professor Orton in his reports on the counties of 

 southwestern Ohio, though he did not recognize the moraine and conse- 

 quently indicated the boundaries of the extramorainic tract in only a gen- 

 eral way. Thus, in his report on Warren County, he calls attention to the 

 fact that the southeastern townships are covered with white clays, while in 

 the northern townships bank gravel is met with on the highlands as well as 

 in the valleys.^ In his report on Butler County (a county lying mainly 

 witliin the district covered by the Wisconsin ice invasion) he calls attention 

 to the bowlders that occur plentifully at all altitudes, while in his reports 

 on Hamilton County (a county lying mainly outside the outer Wisconsin 

 moraine) he calls attention to the scarcity of the bowlders. In the report 

 of the Indiana survey on the southeastern counties of Indiana similar state- 

 ments are made concerning the drift in nearly every county lying outside 

 this moraine, it being noted that bowlders are seldom seen except along 

 ravines, and that the uplands contain scarcely any bank gravel; while in 

 reports on counties traversed by the moraine or lying north of it, the pres- 

 ence of bank gravel and surface bowlders receives frequent comment. The 

 contrast between the surface features of these districts is, therefore, so 

 striking that it was remarked long before the nioraines were recognized. 



Soine of the exposures of lowland drift in southwestern Ohio merit 

 special mention. One of the most extensive is found along the line of the 

 Cleveland, Cincinnati, Chicago and St. Louis Railway, between North 

 Bend and Cleves. Here there is a gap in the rocky ridge which lies between 

 the Great Miami and Ohio rivers, in which there has been a drift filling to 

 a height of 150 to 170 feet above these streams. The railway has made 

 a cut 80 feet deep in the summit of the gap withovit encountering rock; 

 while a well in North Bend near the south end of the cut does not reach 

 rock at a depth of 73 feet, though its bottom is nearly as low as the present 

 river bed. Within 80 rods either side of this cut the limestone ledges rise 

 to a height of 200 feet or more, while on portions of the dividing ridge 

 between the Miami and Ohio rivers the I'ock surface reaches an altitude of 

 fully 400 feet above these streams. Both the railway cutting and the well 

 are mainly through till. There are, however, assorted beds associated with 

 the till. In one place on the west side of the track a funnel-shaped sand 



^Geology of Ohio, Vol. Ill, p. 387. 



