Page:The American Cyclopædia (1879) Volume IV.djvu/760

744 a bed of lignite 5½ ft. thick, 5 m. E. of Don Pedro. A number of other valuable beds have been reported near San Felipe, and still more abundantly northward, around Santa Fé and up to the Eaton mountains. The coal of Placiere mountain, which is partly anthracite, is 5 to 6 ft. thick. The following section, taken at the foot of the Raton mountains, shows the average distribution of the lignitic formations of this southern basin:

This section rests upon a series of hard coarse sandstone, remarkably mixed with fragments of marine weeds and pieces of bark and of wood, marking this formation as the result of marine deposits along the shores. This, like the alternation of the strata marked upon the above section, especially the deposits of fire clay under each bed of lignite and of shale and shaly sandstone above, gives to the distribution and composition of the lignitic strata an evident likeness to those of the old carboniferous measures. From Trinidad or from the Raton northward to the Spanish peak a number of coal beds have been reported from the same basin as far north as Chicosa, 20 m. from Trinidad. The coal of this country is of a remarkably good quality, some being compact enough to furnish hard coke by distillation, and others producing by the same process a large proportion of illuminating gas. 2. The Colorado lignitic basin, from Pueblo to Cheyenne, covers a wide field, but is to the south at least broken into small isolated areas. One is in the Arkansas valley, E. of Cañon City, with beds of excellent coal, varying from 6 in. to 8 ft. A small basin E. of Colorado Springs has as yet given mere indications of coal in thin beds of 2 to 3 ft. But further north, and from the North fork of Platte river to Cheyenne, the lignitic measures follow the base of the mountains nearly without interruption, furnishing an abundance of fuel to the already large population of the country and to the railroads. Beds of lignite have been opened near the canon of the South Platte, 5 ft. thick; then in a continuous direction northward, near Green mountain, 7 ft. thick; and at and around Golden, from 4 to 11 and even 14 ft. thick. Five miles N. of Golden, on the Ralston creek, a coal vein is worked averaging 16 ft. in thickness without any parting. Still further N. toward Marshall's a number of beds have been tested varying in thickness from 5 to 9 ft.; and at Marshall's numerous beds have been tested and some worked, varying in thickness from 4 to

11 and 14 ft. Beds of the same kind and of equal thickness are worked still further N. and E. on Boulder creek, Erie, Thomson creek, and Cache la Poudre river. Thus the continuity of the basin appears to be ascertained from the North Platte to near Cheyenne. In width the measures appear to be continuous from the base of the mountains to the Platte, about 15 m. from W. to E. There they pass under more recent formations, and of course may be reached by shafts further E. It is to be remarked, however, that the coal becomes less compact and therefore more subject to disintegration by atmospheric influence, and even liable to spontaneous combustion, in proportion to the distance from the base of the mountains. 3. The lignitic basins along the Union Pacific railroad from Cheyenne to Evanston. On this line the first lignite basin is exposed at and around Carbon. It is of small area, but its beds are thick and the coal of good quality. From Carbon, over lower formations, the railroad passes to a new tertiary and lignitic basin with some thin beds exposed, at Creston, Washakia, &c., and then to a rich productive lignitic region in entering Bitter creek and following it from Black Butte to Rock Spring. At Black Butte three beds of coal are exposed, one of which is worked 8 ft. thick. At Rock Spring an upper coal of excellent quality is worked near the surface, 8 ft. thick, and a lower coal, equally good but only 4 ft. thick, is worked 2 m. E. of the village. A boring made at Rock Spring for the purpose of obtaining fresh water has exposed the remarkable development of the tertiary measures in this country. Below the main coal the record of the boring indicates 41 ft. of lignite in 700 ft. This is about the same amount of coal indicated at Marshall's in a section of about 500 ft. of measures. From Rock Spring to Evanston, a distance of 130 m., an upper tertiary formation, mostly of shale, overlies the lignitic. It has no coal; but some of its beds of shale are so bituminous that in some localities they are worked and used for fuel. Evanston and Coalville are the two last localities where lignite beds have been opened for the use of the Union Pacific railroad. At Evanston the Wyoming coal company works the bed 14 ft. thick, interlaid by three slate partings of a few inches each. The Rocky mountains coal company, adjoining the first, has the same bed of a greater thickness, 43 ft., interlaid with numerous beds of clay and shale. This lignite bed is comparable in its productiveness to the great mammoth bed of the anthracite of Pennsylvania. It however occupies a very limited area. The Coalville beds, at a short distance from Evanston, have been considered by some as identical with the Evanston deposits, and by others as from an older formation, the upper cretaceous. The northern lignitic basin was the first dis- covered and recorded in the history of the United States. It is however far less known than the others, being as yet out of the lines