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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the lakes, icebergs were detached from them, and floated southward,
sowing sand, gravel and boulders broadcast over the southern shallows,
just as they are now doing over the banks of Newfoundland and the
bottom of the Antarctic ocean.
6th. During the water period, the old, deeply excavated channels of
our river system were silted up-in many cases entirely obliterated-and
up to a certain level all the asperities of the surface smoothed over by the
Drift deposits, just as minor inequalities are effaced by a fall of snow.
7th. Following the water period, ensued an era of continental elevation, which progressed until the present level was reached, and the
Champlain clays and the other Drift deposits were raised several hundred feet above the ocean level. By this elevation of the continent most
of the old lines of drainage were re-established, and the rivers began
the work of clearing out their old channels. In most cases this work is
not yet half done, and in many-as the Genesee, at Portage, New York,
Rocky River, in Cuyahoga county, 0., and others too numerous to mention-the line of lowest levels taken by the new streams did not follow
their old routes, and- new channels were formed. Some of these have
been cut down one hundred feet or more in the solid rock, so that this,
the last phase in the Drift phenomena, has consumed ages of time.
8th. The last emergence of the continent took place slowly, as we
know, and its progress was marked by periods of repose. In these intervals of rest our terraces, old shore-cliffs and lake ridges were formed,
and this may be properly designated as the Terrace epoch. Local and
minor terraces are formed by constantly deepening streams swinging
from side to side in their valleys, but all the great and general terraces
were formed by the arrest in dead water of the materials transported by
flowing water. Old shore-cliffs are beautifully shown in many places
along the lines of outcrop of the Conglomerate and BereaGrit in Lorain,
Medina, Cuyahoga, Geauga, Lake, &c. The lake-ridges mark old shore
lines, on a sloping surface composed of drift materials. Just such are
now being formed around the south end of Lake Michigant between
Cedar Point and Huron, on Lake Erie, and in a thousand places along
the Atlantic coast, especially in Virginia and the Carolinas, In the
north-western portion of Ohio the lake-ridges form -a series of curves,
imperfectly parallel with each other and the present lake shore. From
the nature of the material composing them, and their elevation above
the surrounding surface, they are always well drained, so that the roads
of that section are often located on them. The "ridge roads" are well
known, and they mark the lines of the principal ridges.
The formation of these ridges was the last act in the drama of the
Drift. When the upper ones were formed, the whole lake basin and
much of the country bordering the upper Mississippi was submerged by