580 GLACIAL FOKMATIONS OF ERIE AND OHIO BASINS. 



the Fort Wayne. On this plain the amount of undulation is very slight, 

 even in the district outside the beach, while on the portion inside or below 

 it the waves have smoothed the surface to such a degree that scarcely a 

 discernible undulation remains. 



The drift on this plain is thinner, on the whole, than on the moraine, 

 and its thickness varies, as does that beneath the moraine, there being a 

 thinner sheet in the region south of the Maumee than north of that stream. 

 From Findlay, Ohio, westward to the State line the general thickness 

 scarcely exceeds 20 feet. In the Indiana portion of the plain the thickness 

 is 40 to 60 feet, while in northwestern Ohio it is fully 100 feet. 



Aside from fhin deposits made by the glacial lake, which to some 

 extent cover the surface of this plain, the drift is mainly till. An occasional 

 well, however, penetrates considerable sand and gravel. Thus at Bryan the 

 drillers report a thickness of about 60 feet of quicksand, or more than one- 

 third of the di'ift section. 



In the vicinity of Auglaize River, from near Ottawa to its mouth, there 

 are deposits of yellow clay several feet in thickness in which pebbles are 

 very rare. Similar deposits have been reported by Winchell to occur along 

 the Maumee Valley. They are probably due to the lake occupancy of that 

 region which followed the glaciation, but the precise mode or modes of 

 deposition can not be stated. The fineness of material distinguishes these 

 deposits from the gravel and sand of the beach lines of the old lake bottom. 



The discussion of the beach lines which traverse this plain and of the 

 southwestward outlet of Lake Maumee follows the description ot the Defiance 

 and other moraines, with which they are correlated, a knowledge of the 

 moraines being necessary to a proper understanding of the beaches or lake 

 features. 



STRI^. 



Several observations of striae in the district lying between the Fort 

 Wayne and Defiance moraines are reported by Winchell and others by 

 Gilbert. Their bearing, as shown by the following list, varies from south- 

 west to nearly due south. 



