SECTIONS OF OTITEIt SEAMS.
Fig. 28 is a section of Scranton D vein, or our H, which lies above the Primrose, and corre sponds with the Orchard. This section is from the Bellevue mines, and is not worked; at other points it is found in a workable condition, and ranges from five to seven feet in thickness.
Fig. 29 is F, having the same denomination in both nomenclatures, and corresponds with the Holmes, which lies between the Mammoth and the Primrose. This section is from the Diamond Mines, and is near its average proportions and condition in the Scranton district.
Figs. 30 and 31 are I and K at Scranton, and C and B, as we have named them, and as appear on their face. Fig. 31 corresponds to the Buck Mountain vein, which will be found fully exem plified in other regions.
The highest vein at Scranton is C, or I of our scale. The accompanying notes show its size and character.
Seam D, or H, lies under the Mammoth, and corresponds with the Wharton or Skidmore. Its size in the Scranton district varies from seven to nine feet, as a mean, but sometimes it is much less. C and B are worked and used as furnace-coals by the Lackawanna Iron Company.
The total thickness of the workable scams at Scranton is about 62 feet; but of this thickness not less than 20 feet are rejected as refuse or con sidered unworkable, which reduces the amount of productive coal to 42 feet. The breadth of the basin at Scranton or vicinity varies from three to five miles, and may be estimated, as a mean, at four miles, underlaid by the lower veins. The upper veins do not cover more than half this area:
consequently, the workable or productive thickness cannot be estimated as an aggregate over the entire area. We think that 25 feet total thickness over the entire area of the four miles breadth will be fully up to the standard. The length of the Scranton district is not defined, but the above estimate will hold good throughout the Lackawanna region, from Pittston to its eastern extremity.
The mode frequently pursued of finding the total working thickness of coal, and estimating its productibility over the entire area of the field or basin, is seldom practicable. In deep basins, where the veins dip at a high angle, the total thickness will often more than cover the area of the surface; but this is oftener the exception than the rule.
The composition of the sedimentary strata, or the materials constituting the coal measures at their eastern extremity, is finer in grain and appear ance than near the centre of the basin at Pittston or portions of the field farther down. It would appear, from these circumstances, that the current depositing the sediment of this portion of the coal-field came from the west; but the inference, from the nature of the sediment, would be that it came from some central portion of the field.
There is no evidence of a rapid current flowing east from Pittston, but there is of one flowing west.