332 DESCRIPTIONS OF MINERALS. 
to 20 per cent. The more western parts of the anthracite coal fields 
afford the free-burning anthracite, or semi-anthracite, as at Trevor- 
ton, Shamokin, and Birch Creek. 
The coal-formation of the Carboniferous age in Europe has great 
thickness of rocks and coal in Great Britain, much less in Spain, 
France, and Germany, and a large surface, with little thickness of 
coal, in Russia. It exists, also, and includes workable coal-beds, in 
China, and also in India and Australia; but part of the formation in 
these latter regions may prove to be Permian. No coal of this era has 
yet been found in South America, Africa, or Asiatic Russia. The pro- 
portion of coal beds to area in different parts of Europe has Leen 
stated as follows: in France, 1-100th of the surface ; in Spain, 1-50th; 
in Belgium, 1-20th; in Great Britain, 1-10th. But, while the coal 
area in Great Britain is about 12,000 square miles, that of Spain is 
4,000, that of France about 2,000, and that of Belgium 518. 
Mineral coal of later age than the true Carboniferous era occurs in 
various parts of the world. ‘Triassic or Jurassic coal, of the bitumi- 
nous variety, occurs in thick workable beds in the vicinity of Rich- 
mond, Virginia, and also in the Deep River and Dan River regions 
in North Carolina; and it constitutes very valuable and extensive 
beds also in India. In England, at Brora in Sutherlandshire, there 
is a bed of Jurassic coal. Coal of the Cretaceous and Tertiary eras 
constitutes important beds in various parts of the Rocky Mountain 
region, in the vicinity of the Pacific Railroad and elsewhere. Some 
of the prominent localities are : In Utah, at Evanston and Coalville 
(in the valley of Weber River), etc.; in Wyoming, at Carbon, 140 
miles from Cheyenne ; at Hallville, 142 miles farther west ; at Black 
Butte Station, on Bitter Creek ; on Bear River, etc.; in the Uintah 
Basin, near Brush Creek, 6 miles from Green River; in Colorado, at 
Golden City, 15 miles west of Denver, on Ralston Creek, Cceal Creek, 
S. Boulder Creek and elsewhere ; in New Mexico, at the Old Placer 
Mines in the San Lazaro Mountains, etc. The coal is of the bitumi- 
nous or semibituminous kind, related to brown coal, and is often im 
properly called lignite. That of Evanston (where the bed is 26 feet 
thick) afforded Prof. P. Frazier, Jr., 837-88 per cent. of volatile sub- | 
stances, 5-6 of water, 7-8 of ash, and 49-50 of fixed carbon. At the 
Old Placer Mines, New Mexico, there is anthracite, according to Dr. 
J. LeConte, affording 88 to 91 per cent. of fixed carbon ; specimens 
from there, analyzed by Frazier, were semibituminous, affording 
68-70 per cent. of fixed carbon, 20 per cent. of volatile substances, and 
about 3 per cent. of water. The region of the Old Placer Mines is one 
of upturned and altered rocks, like the anthracite region of Pennsyl- 
vania. Other similar beds occur toward the Pecific coast, the most 
valuable of them in Washington Territory, Seattle and Bellingham 
Bay, and on Vancouver and adjacent islands in British Columbia, 
