1871.] 49] 
[Lestey. 
. 4 
and shoved the 10,000 feet of Carboniferous, Devonian, and Silurian Form- 
ations over each other, like cakes of ice in a river freshet, it would be 
premature here to discuss. 
The consequence has been, that along the straight lines of these cracks 
—lines running for fifty or a hundred miles,—the coals at the top of the 
system abut against the limestones near its bottom. 
Another consequence has been that no coal is to be found but on the 
north side of each crack. The whole mass of rocks above the line A—B 
has been removed (it is needless to describe the process, which is still 
going on and can be studied by any observer), so that the vast coal field 
which once covered this country is no longer in existence ; and the only 
remnants of it left are long stripes, a few hundred yards wide, running 
alang the north lip of each crack. 
A third, and equally important consequence, has been, that even this 
poor remnant of the Coal-Measures, where it is left, consists of only the 
very lowest bed or the two lowest keds of the Coal Measures, the poorest 
of all the coal beds of the system. Fig. 2 will show how this result 
occurs : 
eee 
rei 
SSS LOWER SILUR, 
LIME STONES. 
It is not until, going north 30° west, several such downthrows with 
their comparatively worthless coal fields (so to call them) have been 
passed, that the real coal field of the country is reached. Its southern 
edge runs along a straight downthrow lying just north of the Clineh 
River. 
I shall first take up this line at Guest’s River, in Wise County, 
and follow it northeastward, ascending Clinch River ; and I will give see- 
tions of its Coal Measures, wherever I studied them. 
Stone Mountain, which is the south border of the Guest River Coal 
Fields, in Wise County, is cut throughby Powell’s River at the Big Gap! 
Some miles further east its summit is notched by a wind-gap (Little 
Gap), through which the turnpike from Wise County Court House 
(Gladesville) to Scott County Court House (Estillville) passes. The 
lowest coal bed is opened on the side of the road a quarter of a mile before 
