OF DENISON UNIVERSITY. 7 
r^-'ised forever beyond the creative touch of the ocean. The Waverly", 
group of rocks is the result of the quiet but constant efforts of our 
most modern sea. Farther east, however, the sea still continued, but 
cut off from direct communication with the westerp ocean and only 
now and then keeping up the union at the south. The townships of 
Madison and Hopewell were covered by shallow lagoons of salt water. 
It was now a 'period of quiet. The gradual formation of a ridge of 
considerable width, along the axis, extending from Cincinnati to To- 
edo, had cut off the “sou-western,” which had stunted vegetation, 
land along the borders of the steaming lagoons a dense forest of ferns 
and succulent vegetation of unfamiliar kinds sprang' up. The lepido- 
dendrids, whose trunks had occasionally been preserved in qhe sand- 
bars of the VVaverly sea, gave place to a more dense growth, , which 
literally buried itself under its own profusion and the decaying boughs 
were soon submerged by the variable, though shallow waters. There 
were, however, constantly recurring periods when the ocean asserted 
its ascendency; local or general depressions were followed by inva- 
sions of deep arms of the sea, which eroded the distant granite or 
nearer sand hills and covered all evidences of forest luxuriance with 
sand. The animals which swarmed in the shallow lagoons were such 
as are found everywhere in the coal measures and the accompanying 
plates illustrate the most important species. 
The above history is recorded in alternating layers of shale, coal, 
and white sandstone. In the following diagram the sequence of strata 
is illustrated, while the sections of Fig. 2 show the chief observed ex- 
posures and their relations, as further indicated upon the geological 
map. 
(The section represented in Figure i, is, in general, east and 
west, but there is also introduced a partial section from Madison town- 
ship, which is nearly north and south, exhibiting a greater dip, proba- 
bly of a local nature, as above indicated. The vertical scale is greatly 
exaggerated — 50 feet vertical, equalling one mile horizontal.) 
