AQ : GEOLOGY OF OHIO. 
history, it should include them, as this was a period of submergence of 
the Mississippi and Ohio Valleys, and the time when the lake basin was 
filled with water to the brim; the time when the sediments brought 
down by the rivers were deposited in sheets, out of which the streams, 
with greater descent and more rapid flow, have cut the terraces that 
border them. Professor Dana, in his papers on the Drift of the Connec- 
ticut Valley, questions Hitchcock’s conclusion that the terraces found 
there are records of submergence, and were produced in the dead water 
of an arm of the sea, and he attributes them to the great volume of 
the rivers flowing from the melting glaciers. There can be no question, 
however, that the terraces of the Ohio Valley were formed in quiet water. 
This we learn from the accurate stratification of the materials composing 
them. The section of the Valley Drift in Mill Creek Valley, at Cum- 
minsville, given by Professor Ortea (Vol. I, p. 433), is demonstrative of 
this, for it is impossible that these stratified materials could have accum- 
ulated here simply by current action. It may be further said that the 
natural and inevitable effect of an immense increase in the drainage 
flowing through the trough of the Ohio from the melting of the glaciers 
without dead water to check it, would have been to sweep it clean through- 
out its entire length. 
KAMES. 
The gravel hills which cover the summit of the divide between the 
waters of the lake and the Ohio, present the most difficult problem of 
our surface geology. Their affinity with some of the Kames and Hskers of 
the British Islands, and the Asar of Scandanavia, is unmistakable; and 
if a satisfactory explanation of the origin of such of the Kames as re- 
semble ours, had been offered by the Wuropean geologists, it would be 
equally applicable here; but no theory yet proposed fully satisfies the 
éonditions of the problem. The fact seems to be that the collections of 
gravel and sand, which have been called Kames, are not all alike in 
structure or history. Some of them are long and narrow ridges, located 
in valleys or on comparatively low ground, and evidently mark the lines 
of ancient sub-glacial rivers. The general character of these is well 
shown in the map of the Asar, in the basin of Malar Lake, copied from 
Tornebohm, on page 408 of Geikie’s ““Great Ice Age.” Similar ridges, in 
the valleys of the Connecticut and Merrimac, have been studied with 
much care by Mr. Warren Upham, of the Geological Survey of New 
Hampshire. He attributes these linear Kames, as do Tornebohm and 
Hummel, in Sweden, to the action of sub-glacial rivers. By Professor 
Dana, they are called sub-glacial moraines. Quite another kind of Kames, 
although possibly produced by some modification of the same cause, are 
the hills of sand and gravel which frequently occupy broad and high 
