THE NEW RIVER COAL-FIELDS.
These coal-fields are located principally in Montgomery and Pulaski counties, in Southwestern Virginia, and on the waters of the New River, which is.a, continuation of the Great Kanawha. The formation of which these fields are parts is very extensive,—apparently of equal extent to the vast area of the Appalachian formations, or the Vespertine period of the Palaeozoic strata. It undoubtedly belongs to the proto-Carboniferous, or lower coal measures, and is, consequently, older than the true Carboniferous of the Alleghany and the Western coal-fields. Its place is between the red shales of the East and the Old Red Sandstone, or in the Vespertine of Rogers, and below the Mountain or Carboniferous limestone of the Western formations.
The outcrops of this strata, and frequently its accompanying thin seams of coal and ,carbonaceous shale, can be traced from the Sharp Mountain, and the northern limits of X, or the Vespertine, to Tennessee, south of which it does not come to the surface, as far as our experience goes. It has been picked and pried into at many localities, and occasionally thin seams of crushed and impure coal are found, generally anthracite in cha racter, but too impure, irregular, and thin to be of any certain commercial value, except in the single instance of the New River coal-field, where it has been developed in several beds of workable coal, partially anthracite. North of Harper's Ferry, on the Potomac, this formation seems to lie west of the Great Valley ; but on crossing the Potomac it enters the valley known as The Valley in Virginia, and is found along its western border, at the foot of the North Mountains, and in close proximity to the lime stones, where the eastern outcrops of the overlying strata are inverted. Various attempts have been made to mine this coal, on the Juniata, in Sidelong Hill, near the Potomac, at the " Dora Mines," on the north branch of the Shenandoah River, in Augusta county, Virginia, at the " Catawba mines," near Fincastle in Botetourt county, at the Price Mountain and Brushy Mountain mines in Montgomery county, and many points farther south ; but we do not know of any successful mining ope rations except those in Price's Mountain and the North Mountain in Montgomery county, Virginia, and near the New River.
Here the coal is found in two parallel basins, of limited extent, but of considerable depth. Price's Mountain basin is perhaps a thousand feet below water-level, while its highest bed may be found over 500 feet above it. The strata dipping to the east—or nearly so, as the " strike" is north east and southwest—have a gentle inclination of about 25°; but the west dip is inverted, with an angle of 75° to 80° cast. The North Mountain basin has the same gentle east dip and the same abrupt and inverted west dip; but the basin is not as deep as that of Price's Mountain, and the coal is a semi-bituminous, instead of an anthracite, as it is in the former.
Both basins are narrow, single troughs, not over 1000 feet wide, except at the southern end of Price's Mountain, where the measures are "tumbled" or crushed, and dislocated, and the coal worthless. But all these formations partake of the inverted feature peculiar to the Eastern Paleozoic strata, so fully developed in the anthracite formations ; and much of the coal even here, where it exists in its most favorable condition, is crushed and de stroyed as an article of value. The crushing forces of the lateral contrac tion which folded the lithological structure east of the Alleghanies in sharp and oft-repeated axes have been powerfully exerted in this region, and not only crushed and disturbed the coal-seams, but so disarranged the regular order of the strata that much labor and study is necessary to unravel it. But here is the proper place to study those peculiarities, which extend to so great a limit and shroud in doubt so many of our geological problems. The writer spent several months in this locality during 1858-59, and has found the lessons there learned of much value to subsequent investigations throughout the extended line of inverted Eastern strata.