A, OR ALPHA.
This is the lowest consistent coal-bed in the anthracite or bituminous coal measures in the great Appalachian formations. It is frequently over looked and neglected; but we have never examined a locality in any of the true bituminous or anthracite coal-fields in the United States where it (lid not exist. Occasionally it is very small, but it always occupies the same geological position as the first coex tensive coal-bed in the conglomerate rocks. Where those rocks are of extraordinary thickness, even the second and third veins are enveloped in their strata; but where they are comparatively thin, this seam is either close above them, or directly on them.
We not only find this seam•in the anthracite regions, but it is plainly distinguished in the outlying basins of the great bituminous fields. Figure 115, representing the Sullivan county (Pennsylvania) coal, on the Loyal Lock, shows it clearly. It ranges from 2 to 4 feet in that
section, and has an extensive range, but varies much in quality.
Sometimes the coal is pure and excellent in character, but frequently it is coarse and slaty. While the upper veins only exist in limited patches in those outlying basins, this small coal A, existing in the conglomerate generally, has been preserved over a much greater extent of territory, from the greater resistance offered to the denuding forces by the hard and tenacious character of this rock.
On the Great Kanawha, in West Virginia, this small seam is also plainly recognizable on the conglomerate. It is there overlaid by the vein B, corresponding in form and character to the same vein here. It is sometimes cannel in the West.