"THE LOWER COALS form in Western Pennsylvania a system by them selVes, as has been said already. Clinging as it were to the face of the conglomerate, the lower system fared better than the upper one, and has been left to cover an immense area. In fact, it forms by far the largest part—perhaps four-fifths—of all the coal remaining on the surface. In Ohio—except near in all the Western States, it is the only coal, and may have been originally the only coal deposited.
‘,. . . . Wherever the dip is gentle, this lower coal system prevails, the upper being swept away; but where the dip is steep and in the middle of the narrow troughs, it receives the upper system on itself. It furnishes the beds of Northern and Western Pennsylvania as far south as the Cone maugh or Kiskiminetas, those of the Alleghany River, and all the country northwestward of the Ohio. It occupies the west and south of Virginia, and provides the coal of Kentucky* and Tennessee. The cannel is, per haps, exclusive of this system.
. . . . At that time [referring to the early survey of Pennsylvania] a large bed in the upper part of the system was familiarly called the 'Elk Lick coal,' from its locality near the romantic falls of that name in Somer set. This bed, which is the upper Freeport bed of the Kiskiminetas and Alleghany Rivers, seems to be represented by the large upper coal of the Kanawha and Coal Rivers of Virginia, and by the great bed at Karthause and Clearfield to the north. It marks the upper limit of the lower coal beds, and is covered at no great distance by the remarkable sandstone strata hereafter to be discussed [the Mahoning sandstone].
"This coal-bed sometimes rivals the Pittsburg bed in size and purity of minerals, but wants its regularity. This is its fault in common with all the beds of the lower system: they cannot hold their own for any great distance in any given direction. This is particularly true of the large bed B [Buck Mountain], which lies nearly upon the conglomerate, and seems coextensive with the coal-field. • "At Towanda, on Broad Top, at Johnstown, on the Tennessee River, even at St. Louis, its sections are scarcely to be told apart. Everywhere it is about 50 feet above the conglomerate; everywhere it has a small satellite some yards below it; everywhere it is itself a variable stratum from five to twenty feet in thickness,—a double bed, with an even roof and an uneven floor, rising and falling stormily on a sea of fire-clay, which sometimes has a depth of thirty feet."
This terse and graphic description of the lower coals demonstrates clearly the identity of the Mammoth with E, or the Freeport beds, and B, or the Buck Mountain, with the last-named. In fact, the identity is minute and unmistakable, as any one who has followed us will determine. It places the Mammoth, E, beyond a doubt immediately under the Mahoning sand stone; and, since the Pittsburg seam is immediately above it,—the small seam F only intervening,—there can be no doubt in relation to its identity with the Primrose, or G.
It may be noticed that all our sections invariably show a small seam, A, under B, and our description of B will be found to agree fully with the foregoing quotation, with which we not only coincide, but offer it in evidence of the correctness of our propositions. We may, therefore, pre sume the identification to be complete and satisfactory; while the evidence is such that there can be no difficulty in tracing the respective seams through all our American coal-fields, or those of the true Carboniferous era. The bed B, lying about 50 feet over the conglomerate, and over it the fossiliferous limestone and iron ore; the beds E, immediately under the Mahoning sandstone, and in the vicinity of the Curlew, or Freeport, limestone; and the Pittsburg bed G, over the Mahoning sandstone and accompanied by its peculiar limestone and iron ore, are all so easily and readily distinguished that there can be no mistaking them. Confusion may arise in localities, owing to the split or separation of seams; but the main bed is always identical with its prototype, or the accompanying sandstones, limestones, or ores will always indicate the bed and its identity.
On the Great Kanawha the lower coals are perhaps in their maximum size and best condition, and present a magnificent column of 14 seams and 50 feet of workable coal.