Geology

Strachey

OBSERVATIONS ON THE STRATA IN THE SOMERSETSHIRE COAL FIELDS

1719

From Philosophical Transactions of the Royal Society, No. 360, pp. 972–73, 1719.

This is all I can say in relation to the different veins of coal and earth in the coal-works in these parts; wherein all agree in the oblique situation of the veins; and every vein hath its cuff or dives lying over it, in the same oblique manner. All of them pitch or rise about twenty-two inches in a fathom, and almost all have the same strata of earth, maim, and rock over them, but differ in respect to their course or drift, as also in thickness, goodness, and use.

Now as coal is here generally dug in valleys, so the hills, which interfere between the several works before mentioned, seem also to observe a regular course in the strata of stone and earth found in their bowels: for in these hills . . . we find on the summits a stony arable mixt with a spungy yellowish earth and clay; under which are quarries of lyas, in several beds, to about eight or ten feet deep, and six feet under that thro’ yellowish loom, you have a blue clay, enclinable to marle, which is about a yard thick: under this is another yard of whitish loom, and then a deep blue marle soft, fat, and soapy, six feet thick; only at about two feet thick, it is parted by a marchasite about six inches thick. . . .

FIG. 6.—Structure section drawn by Strachey to illustrate his ideas concerning "the different veins of coal and earth," 1719.