The Cmc'innati Eocks. — Perry. 338 
especially of the larger waves observed, are in limestone com- 
posed of coarse well delined fragments in Avhich such action 
would not be possible. We also find that where the waves 
occur in the finer grained limestone the stratification remains 
quite as distinct as in similar strata not thus marked. Had 
concretionary action taken place these lines must necessarily 
have been obliterated. This may be sufficient, but fortunately 
much other evidence is at hand to show that at times, at 
least, the sea was shallow. 
A more extended study of the river quarries near Cincin- 
nati, with but few breaks up to the outliers of the Clinton 
limestone in Preble county, has shown a great numl)er of 
horizons that bear evidence of shallow water conditions. If, 
therefore, we accept Prof. Shaler's and Prof. James' theory 
that each beach-mark represents a period of elevation suc- 
ceeded by one of depression, we must believe in such frequent 
recurrence of these movements that there should certainly be 
left some evidence of them in the strata, such as faults, meta- 
morphism, etc. These have not been observed as far as we 
know, and it appears to the writer that such a theory is 
entirely unnecessary and has been promulgated because of the 
difficulty to completely break away from the old assumption 
that limestone is necessarily the product of a deep sea. It 
would appear that the only foundation for such a theory is 
the fact that above each of these "beach-marks" pure lime- 
stone strata are found. 
The most striking feature of the Cincinnati series from its 
base to its top, is the very regular alternation of strata of 
limestone and shale. Each stratum is sharply defined — there 
is no gradual merging of one into the other. Each limestone 
stratum is nearly pure carbonate of lime and magnesia and is 
succeeded by a stratum, calcareous to be sure, but as different 
from the former, and the plane of conformity as distinctly and 
as sharply marked, as though the conditions of deposition 
were not only entirely different, but were instantly, not grad- 
ually, changed. With the older idea of deep-sea origin of the 
limestone and a shallow-sea origin for the shales, we would 
have to assume a long and regularly recurring series of 
cataclysms to account for the structure observed. Such a 
theory is so at variance with geological concepts that I am not 
aware of its ever having been soberly advanced. Hardly less 
