Terrace Deposits of the MonongaheJa. Itiver. — White. 373 
iiig quite a large area of Pennian shales. Here the following 
structure is exposed at the clay diggings back of Geneva in 
descending to the Monongahela river: 
1. Rounded boulders, sand, and river trash 50 ft. 
2. Soil, boulders, etc., to top of clay bed 5 ft. 
.3. Reddish clay, fine, tough 10 ft. 
4. Clay mixed with sand, and brown iron ore 6 ft. 
5. Bluish gray clay, fine, tough 10 ft. 
6. Bed-rock to level of Monongahela river 140 ft. 
The elevation of low water here is 772 feet A. T. so that 
the rock floor of the old river is now 912 feet A. T. 
The same kind of clay as that at Greensboro and Geneva, 
and which occurs at 150 feet above the river on the Millan 
farm, West Morgantown, was analyzed by Dr. De Roode, 
chemist of the U. S. Agricultural Experiment Station at Mor- 
gantown, W. Va., with the following results: 
Silica 65.95 
Alumina 20.23 
O.xides of iron 3.17 
Lime 0.32 
Magnesia 1.36 
Soda 0.53 
Potash 2.60 
Water and loss 5.84 
Total 100.00 
At Morgantown, sixteen miles above Geneva, the level of 
the old rock floor at the head of High street is 916 feet A. T. 
or 129 feet above river level, and the same at the University 
buildings, which are situated on top of this old river channel. 
But on the west side of the river, at Keek's hill, where the de- 
posit is 70 feet thick, the level of the old floor is only 905 feet 
A. T. This difference between Morgantown and Geneva is to 
be explained because of the soft shale floor of the old channel 
at Morgantown, which was eroded deeper than the hard sand- 
stone of the old channel at Geneva. 
At Ufflngton, three and one-half miles above Morgantown, 
near the mouth of Booth's creek, we find the level of the old 
floor on the hard Mahoning sandstone under a large deposit 
of sand (brought out of the mountains from the east by 
Booth's creek), at 915 A. T,, or 125 feet above the present 
bed. 
