488 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



OUTER BORDER PHENOMENA. 



The features of the upland portion of the district lying between this 

 moraine and the main morainic system liaving already been discussed, it 

 only remains to discuss the valley phenomena. The moraine is favorably' 

 situated for southward drainage, and the glacial waters appear to have had 

 easy escape at several points. The gravel plams leading southward from 

 this moraine are however not so large as from the main morainic system, 

 but this is probably due to a smaller volume of the streams rather than to 

 an obstruction to their escape. 



The Great Miami appears to have been fed by glacial waters from the 

 vicinity of De Graff, and also from the mouth of Loramie Creek a short 

 distance above Piqua. The exact head of the stream which entered near 

 De Graff was not traced out, but it appears to be located in the eastern 

 tributaries of the Great Miami, no clear indications of glacial terraces having 

 been found along the Great Miami itself above De Graff. The terrace 

 material is, in large part, coarse gravel and cobble, well rounded, and is 

 nearly free from the earthy material which occurs in alluvial terraces formed 

 since the Glacial epoch. The altitude of the terrace from De Graff to the 

 mouth of Loramie Creek is but 20 to 30 feet above the present stream, its 

 usual altitude being about 30 feet. From the mouth of Loramie Creek 

 southward nearly to Piqua there is a terrace standing fully 40 feet above 

 the stream, but farther south it declines to 30 feet or less. Above the mouth 

 of Loramie Creek the terrace has a smooth, flat surface, but for 2 or 3 miles 

 south from the mouth of that creek it is traversed by shallow winding 

 channels and has a somewhat undulating surface. This increase in height 

 and change in appearance are thought to be due to the influx at that point 

 of glacial waters that were heavily charged with sediment. There is an 

 almost imperceptible gradation from the channeled and slightly undulatory 

 terrace to the morainic knolls which occupy the lower course of Loramie 

 Creek Valley. This appears therefore to be the beginning of a moraine- 

 headed terrace. 



Upon passing westward a few miles to the Stillwater River one finds a 

 gravel plain of considerable extent where the stream leaves the moraine, 

 about 2 miles north of Covington. The gravel deposits flank the outer face 

 of the moraine, but southward become gathered into the limits of Stillwater 

 Valley. This appears to have been the main outlet for the glacial lobe at the 



