Trans. N. Y. Ac. Sez. 160 Apr. 24, 
groups known as the Lower Helderberg, Clinton and Knox or Calci- 
ferous. 
The existence and excellence of the iron ores of Southwest Virginia 
have been known for many years; but the chief interest of the region 
now centers in the coal deposits, whose value and accessibility have 
been ascertained very recently. The coal occurs at three horizons: 
The Coal Measures, 
The Quinnimont Group, 
The New River Group. 
The area of the Coal Measures in Virginia is comparatively small, 
probably less than 600 square miles, the greater part of the field being 
in Kentucky and West Virginia. It occupies portions of Lee, Wise, 
Russell and Buchanan Counties, lying along the Kentucky border. The 
most readily accessible part is that in Lee and Wise Counties, and is 
drained by Powell River, a large stream entering Clinch River near 
Knoxville, Tennessee. Stone Mountain, a bold ridge of vertical con- 
glomerate and the southeastern wall of the coal-field, is broken by two 
gaps, through which the Powell River and its North Fork flow. These 
can be reached by following the river from Knoxville, or by a shorter, 
though more difficult, route from Bristol, on the Norfolk and Western 
Railroad. The latter route has been chosen, and a narrow-gauge rail- 
way is in course of construction. 
Measurements on the head waters of Powell River, behind the “ Big 
Stone Gap,” afforded me a vertical section of nearly 2500 feet of Coal 
Measures, containing twenty-one coad beds, varying in thickness from 
four inches to fifteen feet; but the productive part of the section is 
confined to the lower 920 feet, the beds higher up being very thin. 
This section doubtless represents all the Coal Measure groups of Penn- 
sylvania, but detailed comparisons are impossible for the present, there 
being no limestones or other fixed horizons to be used for that purpose. 
Four of the coal deds deserve notice. Two beds of sf/cnz are found 
high up in the productive portion of the section. They are separated by 
an interval of 70 feet, and are from 3 feet 6inches to 4 feet thick. Their 
coal is a hard gray splint, very like that obtained on the Kanawha. 
Analyses by Mr. A. S. MCCREATH show that this Powell River splint 
contains little more than 3 per cent. of ash and less than one-half of 
one per cent, of sulphur. The Kelly Coal-bed, 215 feet below the lower 
splint, is from 2 inches to 15 feet thick, but in a large part of the 
area maintains a thickness of from 5 to 7 feet. The middle bench, 2 
feet 6 inches thick, is an admirable gas coal, the lower bench is a 
fair splint, while the upper bench is worthless. Mr. MCCREATH 
found in the middle bench, .890 per cent. of ash, .771 per cent. of sul- 
phur, while the volatile matter is 38.850. The /sdboden bed is 50 feet 
