28 GEOLOGY OF OHIO. 
stated to have been formed “during the ice period, or at an earlier date.” 
On page 12, of Chapter XXX, it is said, “Some of the channels were 
in part formed long anterior to the ice period, as all of the area of the 
Eastern, Middle, and North-western States has been a land surface 
traversed by drainage lines since the close of the Carboniferous period. 
‘We may, therefore, conclude that many of our great arteries of aqueous 
circulation have been in action all through the Mesozoic and Tertiary 
Ages. The continued study of these interesting features in our Surface 
Geology, has led to the conclusion that most of these buried river chan- 
nels are pre-glacial, and that they form, as suggested in the quotation 
above, a portion of the surface erosion, suffered by this part of the con- 
tinent during several geological ages. The facts upon which this con- 
clusion is based are— 
Ist. Many of these channels are deep and narrow gorges, such as are 
produced by running streams, and not by glaciers, and these bear no ev- 
idence of ice action. 
2d. They are found south of the line to which the glaciers reached, 
and in that region ice could have taken no part in their formation. 
od. Some of them have been filled and obliterated by the bowlder 
clay, showing that these were river channels which antedate the ice 
period. 
Many of these old channels have, however, been filled with and modi- 
fied by ice, as the valley of the Cuyahoga, the bottom of which is glaciated 
at Boston, twenty miles from its mouth. In this instance the direction 
of the valley accorded with the line of motion of the great glacier which 
passed across the lake basin, and it is probable that all the old channels 
within the glacial area that had a north southerly direction, have been 
occupied and modified, like the valley of the Cuyahoga, by some portion 
of the ice being pressed into and moving through them. It is probable, 
also, that the lines of these old channels were frequently followed by 
local glaciers, as they would then as before be channels of drainage, and 
the consolidated water would naturally move along the lines of lowest. 
levels, as fluid water had done. As was suggested in the second volume, 
it is even probable that the basins of Lake Erie and Lake Huron were 
formed by local glaciers, which followed and enlarged pre existing river 
valleys. | 
Prof. EK. B. Andrews prefaces his report in Vol. II with some pages 
devoted to surface geology, in which he alludes to these buried channels. 
On page 45, after referring to the facts cited by the writer, he says: 
The larger streams in the Second District, (south-eastern quarter of Ohio) had, at some: 
time antecedent to the Drift era, large portions of their beds deeper than now, as shown: 
