522 GEOLOGICAL HISTORY OF THE GULF OF MEXICO. 
During the past season, I desired, as occasion was afforded, to verify or i 
disprove, by an actual list of facts, the previous views in regard to the 
question of southern Drift. Taking the circuit of the Atlantic and Gulf 
wept and thence proceeding up the valley of the Mississippi, I discovered 
t almost every step what to me is unmistakable evidence e glacial 
agency, all the way around from Virginia to Illinois. I have studied 
the Drift of New England for years, I think I know it in its main one 
—typical Drift and modified Drift in most of its varying forms. Now, in 
all the states referred to, I found that which I could not distinguish, after 
making the necessary allowance for local differences, from New England 
rift. 
As to the direction in which the agency worked, I find variations which 
were, no doubt, eagerly AREN by the face of the country; variations 
e indicate that the deposits assumed the form which they now have, 
in what was the closing part of the Glacial period, in the Southern States. 
The beds seem to go'out in rays from the Appalachian mountains, from 
the Blue Ridge towards the Atlantic, in the Gulf States for the most part 
southward, and in the Basin of the Mississippi towards the southwest. 
Reference having been made to a supposed elevation and depression of 
elie 
m 
bering that, in the formation of the immense ice-mass that spread over 
much of the continent, there must have been a considerable depression of 
vat 
‘Sion, and a cause sufficient to account for all the manifestations of glacial 
agency with which we mee 
Prof. E. C. ANDREws said that in the prosecution of the geological sur- 
vey of the State of Ohio by Prof. Orton, he found in the Drift deposit, 
buried beneath eighty feet of drift material, a peat-bed and a buried forest 
Hinincin Ohio. The formation there is coarse gravel and drift aterial, 
and I think not stratified. 
Prof. Rırcaard OWEN mentioned that it has not been adverted to, that 
on the north shore of Lake Superior the rocks which have furnished the 
Drift that we find in the whole Mississippi Valley are in sight. Then, 48 . 
we go south, these detached boulders are found at first in large, then in 
many hundred tons weight down to a ton or two in this region, and final- 
ly, south of the Ohio river, weighing only perhaps from one hundred to 
one hundred and fifty pounds and those giving place in turn to deposits 
in the form of sand, ending finally in beds of sand on the shores of the 
Gulf of Mexico. Now, without stopping to advert to the great theory a$ 
ies Ss as 
