178 TJic American Geologist. March, i899 
A DEEP PRE-GLACIAL CHANNEL IN WESTERN 
OHIO AND EASTERN INDIANA. 
By J. A. BowNOCKER, Columbus, Ohio. 
(Plate VI.) 
The counties in which this study was made include Shelby, 
Auglaize and Mercer in Ohio; and Adams, Jay and Blackford 
in Indiana. The territory lies north of the middle of the junc- 
tion of the two states. 
The topography is either flat or rolling. The latter char- 
acter is due mainly to morainic deposits which extend across 
the territory in a general east and west direction. The di- 
versity is further increased by the valleys of three streams 
which now drain the country. 
The mantle of drift which covers the region varies in thick- 
ness from place to place. Starting in the southeast corner of 
Shelby county, Ohio, drift 180 feet deep is found without 
reaching bed rock. North of the Miami river in the same 
county a thickness of 173 feet is recorded without reaching 
rock. In the northwestern part of this county the drift be- 
comes thinner, the rock lying one hundred feet cr less below 
the surface. In the western part of Auglaize county the de- 
crease in depth continues, the figures ranging from twenty-five 
to one hundred feet. Crossing into Mercer county depths of 
from forty-two to sixty feet are met in the territory lying 
north and south of the Grand reservoir. In the northwest 
part of the county, along St. Marys river, the rock is found 
at the surface. To the south, along the state line, the drift 
grows deeper, attaining a maximum depth of one hundred 
feet, but at two or more localities along the Wabash river the 
rock is again found at the surface. 
Across the state line in Indiana the depths remain about 
the same as in the adjacent territory in Ohio. Along the 
Wabash river in Adams county the rock is found at the sur- 
face. West of the town Geneva depths ranging from twenty 
to eighty feet are reported. To the south in Jay county the 
drift is eighty feet deep at Bryant, while in the western part 
near Pennville it is only forty feet deep. Across the line in 
Blackford county the depth again increases, and figures rang- 
ing from eighty to one hundred and fifty feet are reported. 
The present drainage of the region is through three rivers 
