Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/371

 in the conglomerate. In some places it is very friable, in others it forms a hard stone, in thin strata dipping gently to the north and following the inclination of the hill. Near Bincombe and Doddington it is also found, and in both those places it is very white and friable, and contains a great deal of green and blue carbonate of copper, the latter often beautifully crystallized. It was in this sandstone that the mining near Doddington, already mentioned, § 16. was begun. Near Ely Green it is mixed with large red patches, which are very argillaceous, and are chiefly composed of angular fragments of grauwacke; at the bottom of the section the sand becomes more compacted and seams of stratification are distinct. This sandstone I conceive to be the same as that which lies upon the conglomerate at Alcombe.

§ 30. Besides the conglomerates and the sandstone that accompany them, there is a member of the same series which requires to be more distinctly pointed out. It is a red argillaceous sandstone, containing a variable quantity of calcareous matter, but its most characteristic feature is its being always accompanied by spots and stripes of a greenish colour. These greenish parts are of all sizes, from a mere speck to such a degree of magnitude that they often exceed the red portion of the rock, and when this is the case they become much more indurated, and contain a larger proportion of carbonate of lime. There is seldom any marked line of boundary, the passage from the red to the greenish parts being quite gradual: it is occasionally variegated with yellow, and those places abound with dendritical delineations of manganese. It is of a uniformly fine texture, and I never found it to contain any fragments, either angular or rounded. It is the same rock which covers so great a portion of the Midland counties of England, which contains the gypsum of