THE ALLEGHANY COAL-FIELD IN TENNESSEE.
The geological reports of the coal formations of East Tennessee are use less for all practical purposes ; and, as but little development has been made in mining operations, we are left to our limited knowledge of the region in question for available data.
The coal measures are confined to a narrow boundary, and occupy the high mountain-plateaus which terminate abruptly on the east, above the escarpments of the huge Cumberland Mountains,—a continuation of the Alleghanies,—and are cut off with almost equal abruptness by erosion to the west. The eastern margin of the coal-field is parallel with the moun tain-formation, and comparatively uniform, but the western edges are ex ceedingly irregular and zigzag in their course, which, however, is generally in a southwestern direction and a continuation of the line through Eastern Kentucky.
The coal-area of Tennessee is about 3700 square miles ; but most of it lies in an inaccessible mountain-region, which for a long period must remain undeveloped, while the more available districts supply the wants of the Mississippi Valley as far as fuel is concerned; and the same remarks may apply with equal force to a large portion of Eastern Kentucky. But there are several points where the coals of East Tennessee are available for home-consumption, and to a certain extent for the Eastern markets in North and Middle Georgia.
Chattanooga and vicinity may become a great manufacturing district, since the coal is plentiful and accessible in this locality and iron ore is abundant and rich. Before and during the war, until the evacuation of this great strategic point by the rebels, a large quantity of coal was shipped from this place to Rome, Atlanta, and other places in Georgia, for the use of the rolling-mills and foundries employed in furnishing munitions of war for the rebel armies.
There was also a large amount of pig-iron made here,- and several furnaces were successfully in blast, turning out good coke-iron. But after the occupation of Chattanooga by the Union forces the rolling-mills of Georgia were forced to suspend, for want of coal, since there was no other source of supply except a small and undeveloped body of coal on the Coosa River in Alabama, some 40 or 50 miles below Rome.
The Chattanooga mines were located about 14 miles from the town, on the summit of the Lookout Mountain. They were connected with the place by a railroad up Wills Valley, or, we believe, a continuation of that valley, through which flows the Chattanooga Creek. Coal B is the only productive seam in this region, though C and perhaps D may form in the centre of the long depressions which now hold the coal on the tops of the mountains. It ranges from 4 to 10 feet in thickness.
The next prominent point where coal is mined to any extent is nearly opposite Kingston, on the Tennessee River. Here the river runs close along the foot of the Cumberland Mountains, and the coal is obtained from their summits. It is also mined on the Cumberland River, and at several points on the Tennessee River below Chattanooga, for home-con sumption and use in the furnaces. The usual coal production of Tennessee may be set down at 500,000 tons per annum. We have not been able to obtain any correct sections of the coal on the Cumberland Mountains, but can state that all the available coal must exist in the four lower seams, A, B, C, and D. E does not exist, on account of the limited thickness of the measures. B is the chief productive seam ; its size is, as usual, variable, and ranges from 4 to 20 feet. The following transverse section, from Taylor, gives a slight impression of the form and character of the coal measures in Tennessee. It is very minute in scale, and conveys no idea of the great elevation at which the coal exists on the huge Cumberland Mountains, which tower a thousand feet above the valleys at their base. From this elevation the coal must descend to transportation on the Ten nessee River, since all the coal of this region exists on the mountain-tops.
The Silurian rocks mentioned at f are tilted or inverted by the sharp axes of the folded gneissic strata which form the overlying Silurian and Devo nian in long, narrow and steep troughs and ridges to the east of the Cum berland Maintains, as the same strata are folded to the northeast in the anthracite fields and intermediately.