CLEVELAND MORAINE. 641 



STRUCTURE OF THE DRIFT. 



The upland portion of this morainic belt consists largely of a very 

 stony till from which much of the clay seems to have been removed. 

 Small stones, 3 inches or less in diameter, are often so numerous as to give 

 the drift a gravelly appearance, yet there seems to be little stratification or 

 definite bedding, and, as a rule, tlie stones are not much rounded by water 

 action. 



In the Ohio part of this morainic belt the upland drift is, on the whole, 

 more clayey than in the Pennsylvania and New York portions, and often 

 presents the appearance of the typical till of the plains to the west. 



As indicated in the descriptions already given, there are many gravel 

 knolls and ridges on the uplands, but the}' do not form so conspicuous a 

 feature there as in the valleys. 



In the valleys there is usually at the surface a partially assorted sandy 

 and gravelly drift extending down at least to the level of the base of this 

 moraine. In the knolls there is often a much disturbed and irregular bed- 

 ding. This may be due in part to settling of the beds since their deposi- 

 tion, but in some places it appears to have been produced by the movement 

 of the ice sheet. The outwash from the moraine is generally a fine gravel 

 or sand, showing a moderate current. 



Below the level of the base of the moraine the valleys have been filled 

 with silt and fine sand, some of which is so compact that it is found difiicult 

 to olDtain a well. This silt is apparently in large part a water deposit, made 

 in lakes that were held between the ice front and divides to the south. 



Bowlders of granite and other crystallines abound all along the moraine, 

 and are, on the whole, much more numerous than on the bordering non- 

 morainic tracts. 



The largest and most interesting exposure found in this moraine is the 

 gravel pit opened by the Youngstown branch of the Lake Shore and Michi- 

 gan Southern Railway, 2 miles north of Kinsman, Ohio, in a large knoll 

 jDreviously mentioned. This knoll is opened from end to end along its 

 western side, and its excavation extends nearly to the central portion. 

 Talus obscm-es portions of the slope, so that contact lines between beds are 

 not readily distinguishable. A maess of cobble and gravel constitutes the 

 body of the highest part of the hill, whose strata sag beneath the high part 



MON XLI 41 



