MAIN MORAINIC SYSTEM OF THE MIAMI LOBE. 357 



TOPOGRAPHY. 



The outer member of this raoraiuic system has, on the whole, stronger 

 expression than the middle and inner members, but it is less plentifully 

 supplied with bowlders. The knolls and ridges in each of the members are 

 of charactei'istic moraiuic types. 



Since the eastern limb is not clearly differentiated into distinct members 

 it may be discussed as a unit. At its northern end it is strongly morainic 

 throughout its entu-e width, consisting of sharp knolls and winding ridges 

 10 to 50 feet in height, thickly strewn with bowlders and enclosing basins 

 5 to 20 feet in depth. The Hogue Summit, 2 miles east of Bellefontaine, 

 which is reported to be the highest point in Ohio (1,540 feet above tide),^ 

 is a morainic knoll having a height of about 40 feet and covering 8 or 10 

 acres. Other knolls in that vicinity rise to within 20 or 25 feet of the same 

 altitude. 



In southern Logan County and in Champaign, Clark, and Miami 

 counties the features of the moraine are extremely variable. In its eastern 

 or outer part are occasional clusters of very sharp and prominent knolls 

 30 to 75 feet in height, illustrations of which may be seen 3 to 4 miles 

 northwest of West Liberty and in the vicinity of Spring Hills, also west 

 of St. Paris and in Honey Creek Valley west of New Carlisle; but much 

 of this eastern part is characterized by a subdued morainic topography, 

 with knolls and ridges only 10 or 15 feet in height, among which shallow 

 basins are inclosed, nearly the entire surface being undulatory. In the 

 western or inner part of the eastern limb a somewhat different topography 

 appears, knolls 10 to 25 feet in height dotting the surface of an otherwise 

 nearly plane tract, and occupying but a small fraction of it. Basins are rare 

 compared with the outer part of the moraine. Bowlders are very abundant 

 l)oth on the knolls and the plane-surfaced tracts. 



Where the moraine-headed terraces or gravel plains connect with the 

 moraine, as in Mad River Valley near West Liberty, and again east of New 

 Carlisle, on Glade and Muddy creeks near Northville, and on Nettle Creek 

 near Millerstown, the morainic knolis come down to the gravel plains and 

 occasionally occur like islands on them. The latter statement is especially 

 true of the district east of New Carlisle, where morainic knolls and ridges 



1 See Geology of Ohio, Vol. Ill, p. 482. 



