Page:A Treatise on Geology, volume 1.djvu/184

From Wikisource
Jump to navigation Jump to search
This page has been validated.
168
A TREATISE ON GEOLOGY.
CHAP. VI.

section is, however, much in accordance with the views of Hoffman, who, in north-western Germany, finds the carboniferous limestone and coal buried in a great body of red sandstones; the lower ones being attributed to old red, the upper ones to new red.

The total thickness of coal workable in the English and Scottish coal fields, is generally about 50 or 60 feet: this is, in most districts, divided into 20 or more beds, of a thickness from 6 feet to a few inches, alternating with from 20 to 50 or 100 times as great a quantity of sandstones and shales. But in some districts (Cumnock in Ayrshire, Dudley and Bilston in Staffordshire) many beds of coal, deposited one upon another with but little intervening earthy matter, constitute one mass 30 or 40 feet in thickness, in which the different beds are easily traced, and possess different qualities, probably depending on the original differences of the component vegetables, and the manner of their accumulation.

In the Newcastle coal district, the coal beds are arranged in the following order by Mr. Westgarth Forster:—

Yds. Ft. In. Yds. Ft. In.
Brown post, or grindstone sill 24 0 0
Coal 0 0 6
Rock measures 10 0 0
Coal 0 0 8
Rock measures 22 0 0
Coal 0 0 6
Rock measures 15 2 6
Coal 0 1 0
Rock measures 1 1 1
Coal 0 0 6
Rock measures 7 1 0
Coal 0 0 8
Rock measures 6 1 0
Coal 0 0 8
Rock measures 19 1 0
Coal 0 1 0
Rock measures 16 0 0
Coal (High Main) 2 0 0
Rock measures 11 0 0
Coal (Metal Coal) 0 1 7