Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/300



12. The stratified rocks which occupy the country to the westward, rise in some places to a considerable height on the side of the range; the highest point where I found them, was on the Herefordshire beacon, at about one third of the elevation of that hill. The particular arrangement of these stratified rocks I shall relate in a subsequent part of this paper.

§ 13. I have deposited in the collection of the Society, a series of specimens illustrative of the mineralogy of the district I am now describing. Among these, there are several which may at first sight appear to be duplicates. but they all possess shades of difference; and in a collection of the mineral productions of any particular district, it is material that every variety should be contained, for by these gradations the connection between rocks of very dissimilar appearances is frequently made out. The specimens of the unstratified rocks are chiefly from the northern part of the range where the rock is most exposed.

Of the unstratified Rocks.

§ 14. Although some of the rocks I shall describe under this head have a slaty structure, and as such, were probably formed by successive deposition; yet as they are of comparatively rare occurrence, and when found, are only in irregular masses without any continued stratification, I shall employ this term to distinguish the rocks that compose the central part of the range, from the stratified rocks, which, as I have already said, occasionally rise to a considerable height upon the western side of it.

§ 15. The most northern point where the unstratified rocks are seen above the surface, is about a quarter of a mile in a direct line from