MAIN MORAINIC SYSTEM IN THE GRAND RIVER LOBE. 449 



In the valleys of Shenango and Beaver rivers below Newcastle there 

 is a peculiar combination of moraine and terrace. Near the mouth of 

 the Shenango there are terrace-like benches, about 100 feet high, that are 

 capped by till, and back of these benches on the slope of the bluff morainic 

 features appear. A few miles below, in the vicinitj^ of the glacial boundary, 

 these terrace-like benches break up into a series of reticulated, nearly level- 

 topped ridges, among which basins and low marshy tracts are inclosed. 

 Nearly the entire breadth of the valley is occupied by these ridges and 

 basins, whereas a few miles above a broad, low tract borders the river, 

 leaving the bench and drift knolls referred to as a naiTOw fringe along the 

 bluffs. 



Below Chewton, Beaver River enters a narrow vallej^ or gorge. 

 Bordering the g'orge, at a level 130 to 150 feet above the river, there is a 

 gradation plain nearly a mile in width, which is concealed above this village 

 by the morainic accumulations. This gradation plain with its capping of 

 drift has been considered in the discussion of the deposits of drift older than 

 the main Wisconsin moraine. 



The moraine is best developed north of Chewton, but for 2 or 3 

 miles below this village there are occasional ridges and knolls of morainic 

 type. Foshay and Hice have described some of these as follows : ^ 



Toward the north the plain beai-s upon its surface a large L-shaped kame a 

 mile in length, which reaches down to a point about one-half mile above Rock Point. 

 This kame is composed of stratified gravel and sand and has a hummocky and irregular 

 outline. Several kettle holes are to be seen upon its surface. The direction of the 

 long arm of the kame is north and south, or parallel to the valley of the base-level 

 plain here, while the short arm lies nearly at right angles to the long one and runs 

 eastward from it, but does not reach to the bhifls at the rock gorge. The kame 

 rises to a height of 25 to iO feet above the base-level plain, and is from 100 to 300 

 3'ards in width. It overlies the clayey deposit of the subjacent plain, as proved by 

 excavations into the gravel which reached the clay below, a thickness of 11 feet of 

 the latter being here noted. 



On the base-level plain of the Conoquenessing, which is half a mile wide and 

 typicallj'' developed for about -i miles up that stream and half a mile back from Rock 

 Point, there is another kame about 200 yards in length and 10 feet in its greatest 

 height. On its surface it bears a typical kettle hole, and also another partly formed. 

 The dii-ection of this kame is approximately north and south, or at right angles to 

 the Conoquenessing Valley at this point. The EUwood Short Line Railroad cuts 



'Glacial grooves at the southern margin of the drift, by P. M. Foshay and R. R. Hice: Bull. 

 Geol. Soc. America, Vol. II, 1891, p. 460. 



MON XLI 29 



