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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county, on the Ohio river. While the materials of the drift terraces are
more often gravels and sand, we find sometimes layers of fine clay. A
layer of fine blue clay is found in the terrace at Marietta. This was a
fine sedimentary deposit from quiet water. From the location of this
clay, it might have been dropped from the still water of an eddy made
by the meeting of the two rivers. In the same terrace I have seen a
large rounded bowlder of coal measure sandstone, twenty inches in
diameter, imbedded in a fine yellow clayey sand. It was as much isolated, so far as other adjacent coarse material is concerned, as a granite
bowlder on a western prairie.
The drift in the northwestern part of the District constitutes an almost
continuous sheet, covering the whole surface, and in this unbroken condition extends itself for some distance down the valleys of the Scioto
and Hocking rivers; but, as the valleys become more narrow, the continuity is broken, and the drift is found only in isolated sandbars and
drift plains. At no point in these valleys, nor in that of theMuskingum,
do I find any striation of the underlying rocks, such as, in the more
northern portions of the State, is attributed to the action of glaciers.
The highest elevation on which I have found drift bowlders is on the
summit of Flint Ridge, in Licking county, which is 170 feet above the
adjacent valley. To this add 50 feet as the estimated elevation of the
base of the ridge above Newark, and we have bowlders 220 feet above
Newark, and 374 above Zanesville, and 490 above Marietta, and 729
above Cincinnati. On the hills in Kentucky, in the neighborhood of
Ashland, Greenup county, more than one hundred miles south of Flint
Ridge, I saw drift bowlders 200 feet above the Ohio river, and, in one of
the deep valleys of Scioto, Brush creek, in Adams county, Ohio, I have
seen bowlders of Lake Superior rocks, which had evidently been brought
over the high ground to the north. This high ground cannot be much
less than 700 feet above the Ohio river at Cincinnati. There will doubtless be many similar examples of this kind brought to light during the
progress of the survey. How came these bowlders to be thus left upon
these high hills? If glaciers had reached such elevations, we should
expect to find large accumulations of glacier-worn materials, whereas
we find, in fact, only a very few isolated bowlders. More probably they
were transported by floating ice, but we are yet to find corroborative
proof of the existence of so vast a body of water, filling the Ohio Valley
at Cincinnati to the depth of at least 730 feet. Such a body of water
must have constituted an arm of a gulf, filling the Valley of the Mississippi. It could have had little current, and contained little sedimentary
matter brought in from rivers, since we find neither trace of current
action nor deposited sediments. The explanation of our river terraces
requires the movement of strong currents along our valleys by which