414 The Atnerican Geologist. june, i89$ 
mee-Miami lobe of the ice-sheet in western Ohio and eastern Indiana are 
shown on the map accompanying this paper. In the summary of his 
conclusions, drawn from a very thorough examination of the drift in 
Ohio and the country westward to the Mississippi river, Mr. Leverett 
enumerates the following stages of the Glacial period: 
1. A glacial stage during which the ice-sheet extended farther south 
in western Ohio than in any later stage. During this glaciation the 
scarcity, if not absence, of coarse overwash material seems to indicate 
feeble drainage and low altitude. 
2. A long stage of deglaciation marked by development of soil and by 
attendant oxidation, leaching, and erosion of the drift sheet. The 
character of the changes effected indicates fair drainage conditions, the 
altitude being probably not much lower than the present altitude of the 
region. 
3. A stage of silt deposition during which the highest points in 
southwestern Ohio apparently became covered at flood stages. There 
can be little doubt that the region then stood several hundred feet lower 
than now. From evidence gathei-ed elsewhere it seems probable that 
the silt deposition accompanied a glacial stage whose deposits are con- 
cealed in this region by later drift sheets. 
4. A glacial stage, during which the outermost well-defined frontal 
moraine was formed, with as good attendant drainage as is now afforded 
in the western Ohio region. . The drift of this stage is concealed in east- 
<>,rn Ohio by the later moraines. The main streams at the time of this 
ice invasion flowed at levels 200 feet or more below the level of the up- 
land silt. 
5. A stage of deglaciation of considerable length, with altitude some- 
what as at present, indicated by valley excavation. 
6. A glacial stage characterized by sharply indented morainic ridges. 
The land at this time was probably raised to a maximum of elevation, 
there being ample evidence of vigorous drainage, not only in Ohio, but 
as far to the west as the moraine has been correlated. The ice-sheet 
reached about to the glacial boundary in eastern Ohio, but fell short 
many miles of reaching the boundary farther west. 
7. A glacial stage characterized by morainic ridges of smooth con- 
tour. This stage embraces the final disappearance of the ice-sheet from 
Ohio. A deglaciation interval is believed to have preceded it,but decisive 
evidence in support of this view is not obtained. During the formation 
of these later moraines the land had again an altitude similar to that 
of to-day. 
" Still later," writes Mr. Leverett,"the Champlain submergence of the 
coast and St.Lawrence occurred. It is important to note that the Cham- 
plain submergence is separated from the submergence which produced the 
silts of southern Ohio by the periods of high altitude just mentioned, a 
succession of periods during which all the Ohio moraines, no less than 
twelve in number, were being formed." This opinion, however, seems 
open to doubt. The depression when the silts and loess were being de- 
posited and the marine submergence of the coast of Maine and New 
