W. J. McGee — Geology of the Mississippi Valley. 413 



in direction with the range. The asar are frequently intercepted by- 

 channels of erosion, by which they are divided into ranges of oblong 

 hills, the direction of which is very nearly the same as that of the 

 kames proper. In Dubuque county, Iowa, where these features 

 have been most thoroughly studied, this direction is about S. 75° E. 

 Within 40 miles south-west from there the direction changes to 

 about S. 45° E., and in the next 50 miles the direction becomes 

 a trifle west of south ; and this is the general direction over the 

 greater part of the region examined. 



Though generally independent of the present minor lines of 

 drainage, kames, when they occur singly, often bear a distinct re- 

 lation to neighbouring topographical peculiarities. Thus in Dubuque 

 county, a single kame is often found at the head of a " draw " ex- 

 tending N. 75° W., and communicating with a deeper transverse 

 valley or streamlet. If several such "draws" are parallel, and of 

 about the same length, a series of kames may extend in a direction 

 corresponding with that of the larger valley ; but their longer axes 

 correspond with that of the " draw." Again, when a stream 

 flowing to the north or south bends abruptly to the east for a mile 

 or two, and then resumes its course, a prominent kame, which may 

 be of considerable length, may often be found on the upland east of 

 the bend. A fine instance of this character may be seen at Bock- 

 ville, on the line between Dubuque and Delaware counties, where a 

 kame nearly a mile long lies opposite such a bend in the Maquoketa 

 river. Its altitude exceeds that of all other hills in the vicinity. 

 There is a very small but strikingly characteristic kame near by, 

 directly opposite a steep, rocky ravine on the west side of the river, 

 extending about S. 63° E. The kame is fully 60 feet high, and its 

 base is not more than 200 by 375 feet. Its longer axis extends 

 S. 60° E. 



The ridges already spoken of as extending across a part of 

 Dubuque county from west to east, are believed to be true asar. 

 One, which passes just south of Farley, has been traced over 10 or 

 12 miles, though there are two or three breaks in this distance. 

 The same ridge, probably, extends many miles further westward ; 

 but it is so broken by the two branches of the Maquoketa river and 

 their tributaries that it is difficult to positively establish any con- 

 nexion between the portions supposed to be related. This difficulty 

 is enhanced by the sandy and friable nature of much of the soil west 

 of the easterly branch of the Maquoketa. Similar elevations have 

 but seldom been observed in other localities ; though some forma- 

 tions, believed to be analogous, were recently noticed in the vicinity 

 of Aurora, Illinois. Circumstances prevented their thorough ex- 

 amination. 



Both kames and asar are chiefly composed of members one and 

 two in their proper relative positions, number two being much 

 thickened, and generally stratified, assorted, and laminated. 

 Geikie's description of the kames of Scotland l will often apply 

 word for word to those of this region, except that here they are 

 1 " Great Ice Age," chapters svi. and xyii. 



