VERTICAL SECTION, NORTH MOUNTAIN COAL MEASURES.
Figure 115 is a vertical section of the measures in the principal body of coal lying within the area described, and near where the Berwick turnpike crosses the Loyal Lock, east of Old Shinarsville. The lower bed, A, in this basin may extend over an area of 3000 acres, but the upper bed, E, does not occupy one-third of that area. The basin is limited, but the coal is good, and closer to the anthracite in character than any other de posit of the Alleghany formations. It is bituminous in fracture and appearance, but nearly anthracite in cha racter and constituency, and contains nearly 90 per cent. of carbon.
In figure 115 we find a close resemblance to the anthracite measures, and a perfect identity of the seams, as a connecting link between the two forma tions. This is the most eastern of the Alleghany basins, and the nearest to the anthracite fields. It is, beyond doubt or question, part of, and was once con nected with, the great Alleghany field ; consequently, we need not seek for proof to identify the seams, be cause, if the measures belong to that great field, the seams must also belong to it, and though they may change in size and relative distances, they will always occupy their proper place in relation to , each other.
Our object now is to identify this formation with the anthracite formations, and prove the identity of the respective seams; and, having done this, we submit that the question of identity may be settled as a general application, though we may find difficulty in tracing the seams through all their changes throughout the Western coal-fields. This, however, we believe can be done, and we expect to do it satisfactorily.
Those who have followed us in our descriptions of the anthracite fields, and observed our vertical sections of the respective regions, will at once recognize A, in figure 115, as synonymous with A, or Alpha, in those regions. Here it exists in the conglomerate, and ranges from 18 inches to four feet in thick ness, and is found over a large portion of this field in detached deposits, but only occasionally overlayed with the upper seams. We think this
seam occupies at least ten times the area of the next overlying seam, and perhaps a hundred times the extent of the upper seam, E. The coal of A is generally bright, pure, and excellent for smiths' purposes towards the centre of the field, but is dull and impure towards its margin to the east.
Immediately above A, and only separated by 20 or 30 feet of coarse sandstones and slates, is B, or the Buck Mountain bed, which is a persistent seam, and is as extensive as the coal measures. It is the Blossburg and Ralston working bed, and is generally good and productive, though liable to frequent changes. C, or "Gamma," occupies its proper place, and exists in its usual size and character. It is thin here as in the Broad Top coal field and elsewhere.
D, or the Skidmore, holds its proportion in comparison with the accompanying seams, and occupies its proper place in the measures; though the whole distance from A to E is not greater here than the distance in some of the anthracite basins from D to E,—yet the depreciation of the intervening strata is general and uniform.
E is the Mammoth beyond doubt, and presents its character both in structure and character, as well as its position in the measures. It is a large bed, resembling closely the "Big vein" of the Cumberland region, and is rarely met with in the outlying patches of the Alleghanies. We have been at some trouble and expense in personally investigating this inter mediate coal deposit, for the purpose of following closely the change from anthracite to bituminous, and obtaining a connecting link to identify the seams. We submit the result confidently, as the best evidence of the cor rectness of our propositions.