Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/299

 compounds to which their terms are applied, and particularly those in which theory is involved. They would thus be following a more precise and more philosophical method, the accuracy of their observations would be more firmly relied on in the present day, and there would be a greater probability of their proving valuable in a more advanced state of the science. Those who have had an opportunity of seeing the various rocks to which the names grauwacke and greenstone are applied, will perhaps agree with me in the opinion I have thus ventured to advance.

§ 11. Before proceeding to a detailed account of the several rocks met with in the Malvern hills, I shall point out the general structure of the great masses. The central part of the range, and nearly the whole of the eastern side consist of the different compounds of felspar, hornblende, quartz, and mica, I have already alluded to. These are irregularly heaped together in large masses, and in no part could I discover them disposed in any way that could be considered as continued stratification. In some instances, the materials of the rock are so arranged as to give it a fissile appearance, and in these cases, the slaty structure is either vertical or very highly inclined. But the masses themselves I never found to be of any great extent; and they are frequently inclined to different points of the compass within a very short space. Except in regard to the granite, I did not discover any uniformity in the occurrence of any one compound in particular situations, but all seem confusedly heaped together. The granite is sometimes found in the highest parts of the hills, but chiefly prevails in the lower parts, particularly towards the northern extremity, either in large masses, or what is very frequent, forming veins which traverse the other rocks. These veins or shoots are for the most part narrow, and, as far as'1 had an opportunity of ascertaining, they generally become more so, the higher they ascend.