Age of the Cincinnati Anticlinal. — Foerste. 103 
the axis of the anticlinal is reached. This separation of strata 
along the southern end of the Cincinnati anticlinal, certainly is as 
strong an argument against this portion of the anticlinal axis hav- 
ing been a source of supply of materials in the formation of the 
Upper Silurian strata of Tennessee, as were the facts above given 
against similar claims for the ndrthern end of the same axis in 
Ohio. The Huron shales of Tennessee again cover the entire an- 
ticlinal, thus indicating that the peculiar conditions just noted in 
Upper Silurian times, had ceased. In Kentucky this separation 
of strata by the anticlinal region disappears on going northward. 
In Ohio it seems never to have obtained. 
Although the Cincinnati anticlinal could not have provided the 
great mass of materials necessary for the formation of the sur- 
rounding Upper Silurian, Devonian and Carboniferous rocks, it is 
necessary to determine whether it might have formed a subaerial 
ridge, without providing any considerable share of these materials. 
Any land, for a greater or less time above the level of the sea, 
would at least be subjected to the effects of rain, and be more or 
less cut by the water channels, perhaps of a mild nature, along 
winch the rain would find its way to the sea. The softer the ma- 
terials forming the land surface, the more active would be the 
formation of such drainage channels. During submergence the 
lower courses of the channels would, for a time, be kept clear of 
sediments by the current still coming down along that part of the 
channel still above sea level. In the course of time sediments de- 
rived from the land, would cover these submerged channels ; Cur- 
rents of the sea, even, might throw bars across them, or build flats 
or banks over them ; but these subsequent deposits, would still, 
in their structure, give evidence of the uneven conditions they 
found when they began to cover up the old drainage channels. 
The presence of these, and similar positive evidences of the exist- 
ence of land conditions over the whole range of the Cincinnati an- 
ticlinal axis, rather than the negative evidence derived from sup- 
posed or real absence of marine deposits during certain periods, 
over this area, are needed to determine this question. It has been 
shown above, that the Clinton conglomerate at Belfast, Ohio, can 
not be used as such a proof, and it is too limited in occurrence to 
serve as basis for any general conclusions. 
It remains to consider the possibility of the Cincinnati anticlinal 
