Part I. Report of progress in 1869, by J. S. Newberry, chief geologist. Part II. Report of progress in the second district, by E. B. Andrews, assist. geologist. Part III. Report on geology of Montgomery County, by Edward Orton, assist. geologist.

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Alaska as warm as that of southern Ohio now, (palms growing as far
north as Lake Superior); herds of gigantic mammals, elephants, mastodon, rhinoceras,&c., with great cats and other carnivorous, corresponding
in size and numbers to their prey, the herbivorous, all now extinct, ranging over a fertile and beautiful surface.
b. A pre-glacial epoch of gradual continental elevation, in which the
erosion of our lake basins and river valleys, began long before, was
continued with increasing energy as the elevation of the surface became
greater, giving greater falls to the streams, and supplying, by greater
breadth of surface and better condensers, an increased flow of drainage.
Accompanying this elevation and in part dependent upon it, but mainly
due to astronomical causes, was a depression of temperature which culminated in the " Glacial Epoch," when the continent was many hundred
feet higher than now, the climate of Ohio was similar to that of Greenland at present, and glaciers covered a large part of the surface down to
the parallel of 40 degrees. These glaciers planed down much of the
more level surface, but along the drainage lines widened the valleys of
the water-courses, and excavated the basins of our great lakes. By the
cold of the " Glacial Epoch," the Arctic flora and fauna were brought
down to our latitude; the tertiary flora and fauna driven southward and
to a great degree destroyed.
c. The ice period was followed by another interval of continental subsidence, characterized by a warmer climate, by melting glaciers, by an
inland sea of fresh water filling all the lake basins, and by the deposit
of the clays, sands and boulders of the drift (Erie clays, Champlain
clays, &c.)
d. - Another epoch of elevation, probably still progressing, in which
the water surface has been much diminished, the silted-up valleys of the
streams partly cleared, the terraces and lake ridges formed, and a wide
territory, covered with the drift deposits, opened to human occupation
Much of the topographical monotony which characterizes the northwestern part of the State, is due to the spread of the drift clays over all
the irregularity of the underlying rocks. The system of agriculture
pursued in all this region has followed as a necessity the deposition of
these clays; so that they have not only determined the occupation of a
large portion of our people, but have affected all their modes of thought
and action, and they may almost be said to underlie the manners and
morals, as they do the farms and towns, of all the dairy districts.