Rambles among the Channel Islands / by a Naturalist.

Date:
[1855?]
Catalogue details

Licence: Public Domain Mark

Credit: Rambles among the Channel Islands / by a Naturalist. Source: Wellcome Collection.

    129/402 (page 117)
    which serves to show that they were formed by the deposit of layer upon layer of the sub- stance of the rock,—in a mass of granite. It is all solid, compact, crystalline, and homogeneous, or nearly so. But the rocks of the second series, still belonging to the rocks destitute of organic remains, and including gneiss, chlorite, hornblende, schists, &c., appear to have been formed from alterations taking place in the rocks belonging to the first series, and such rocks, often called metamorphic, exhibit traces of stratification. As a general rule, such rocks appear to be next in point of antiquity to those of the first series. After these, and generally overlying them,—in other countries, not in the Channel Islands,—are found rocks and beds containing various organic remains : and up to the surface itself such remains continue to be found, and in greater abundance. All those strata containing organic remains or fossils are considered to be newer than those of the first and second series, and it is deserving of especial notice, that no such strata are to be found in the Channel Islands. The older beds of strati- fied rock, and the granite, the most ancient of all, form their external structure. It is of rocks belonging to these two classes or series —the rocks of eruption, and the rocks formed by alteration of these rocks—that the Channel