W. M. Fontaine—Primordial Strata of Virginia. 865 
over the fractured outcrop of (8). Next appear the lower 
strata in unchange ition. 
eturning to the line of section, we find the western slopes 
of the mountain overlooking the valley of the James to be 
covered high up with boulders and alluvial matter, by which 
the junction of (10) with the next series (11), and some adjoining 
space, is concealed. The river has at some time flowed several 
hundred feet higher than its present level. 
The series of strata which I have numbered (11) in this sec- 
tion occupies a narrow belt between the mountain last men- 
tioned and James River. The dip is very regular, being about 
55° to the northwest. The rocks, so far as seen, next to the 
mountain, are more or less ferruginous, and local pockets of 
iron ore occur in the sandstones of (10) forming the mountain, 
especially near the line of junction. 
he first rock seen next to the mountain is thinly laminated, 
fragile shale, of yellowish and reddish hues, not fully expose 
Next, to the west, we have bluish calcareous slate, and slaty 
limestone, 50 feet. Then very thinly laminated, firm, deep red 
slates, 60 feet. Next a similar slate of blue color, 15 feet. 
Then a bed of dark blue, hard, and dense limestone, used for 
cement, 13 feet. Then thinly laminated red slates, 20 feet. 
_ Then coarser, and thicker bedded, blue slates, 40 feet. Lastly, 
similar position with respect to the Potsdam strata. They 
this point. 
On the west side of the river is a valley, from half to three- 
quarters of a mile wide, which is bounded on the west by 
a range of heights called “Salling’s Mountain.” I observ 
in the western banks of the stream about eighty feet of fine- 
grained kaolin shales and sandstone, like those of (10), but 
more shaly. These have the same northwest dip; how far 
they extend into the valley I do not know. Prof. Rogers says 
