W. M. Fontaine— West Virginia Asphaltum Deposit. 418 
and that the same bituminous deposits, lying far beneath the 
surface, have produced the asphaltum, and now afford the 
oil of this region. I do not propose to set up any theory to 
account for this state of things, but will confine myself to a 
statement of the facts, so far as I could discover them. 
As stated, the crevice penetrates vertically the strata from 
the surface to an unknown depth. Its width varies with the 
nature of the rocks through which it passes. Its average width 
in the massive sandstone No. 5 is 4 feet; and in this stratum its 
dimensions are greatest. We can stand in this portion of the 
cleft and see the mouth of the adit, 900 feet distant, an evi- 
dence of its perfect straightness ; while, for the vertical distance 
of 95 feet (the thickness of the stratum), a plumb line from the 
top would not touch the sides. On passing into the shales, 
however, the width is diminished, being sometimes not more 
than 23 feet. The direction is also slightly changed from the 
true perpendicular at the junction of the shales and sandstones. 
@ see, in the shaly portions, slickensides and other evi- 
dences of rubbing and sliding. Some of the beds of sand- 
stone have a good deal of shaly matter interstratified, and in 
these the crevice loses width, and becomes more crooked hori- 
zontally ; but in no case in the main workings are the varia- 
tions from regularity very great. In the deepest portions which 
ave been reached, all the rocks have more shaly matter, and 
hence the greatest width here is only about 2} feet. Followed 
Shoulders are more frequent, while the crevice is continually 
: . AW es” are found in all parts, but I 
‘aw more of them here. I have but little doubt that to the 
West the inferior compactness of the strata has distributed and 
teed the action of the rupturing force, and thus prevented 
€ formation of a clear, wide crevice. 
tur; € may, I think, from these facts, conclude that this rup- 
Ming force could not have been shrinkage. 
