Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/79

 at Elginham; near Craster; neat Beadnell; near Belford; and at Tweedmouth in the vicinity of Berwick.

In the north-eastern part of Northumberland, near the sea, the seams are tolerably thick, and very good in quality; that of Shilbottle for instance, which supplies Alnwick with coal, (see the section below.) The mines are usually of inconsiderable depth in comparison of those in the Newcastle coal-field; that of Shilbottle is one of the deepest, measuring 45 fathoms. That of Newton (see the section page 71,) measures 16 fathoms, and some of the pits near Berwick only 15 fathoms. The mines of Stublick and Wall, on the borders of the mountainous district, are severally 16 and 19 fathoms deep, and each contains three seams of coal. (See the sections p. 70.)

The coal alternates with slate-clay, limestone, and sandstone, and at many of the places where coal is worked, limestone is also quarried. In the maritime district, from the Coquet to the Tweed, the measures dip to the south-east, and unlike the beds of the Newcastle coal-field undulate with the surface of the earth.

The following sections will give some notion of the measures that accompany the coal to the north of the mountainous district.