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.

    164/402 (page 152)
    rock is granite, and the overlying rocks are all of the dense, compact, and durable character of metamorphic rocks in general. A few con- siderations will render this more apparent. The position of these islands in the midst of a powerful tidal current, and the fact that the great Atlantic wave is propelled against them with a force but little diminished from its having entered the Channel, deserves particular notice when we seek to account for the pecu- liarities of its coast line. The comparative durability also of the rocks which form it, their chemical composition, and their mechanical structurcj should be borne in mind would we inquire into the effect of such a position upon these islands. It will be again necessary for us to remark upon the waste of the coast by the incessant action of the sea and its restless currents; but in the meanwhile it may be ob- served, that this is very much determined, not alone as to its extent, but as to the form it assumes, by the greater or less resistance of the materials operated upon. The existence of a number of minute bays having strictly defined outlines can nowhere be pointed out in an island the coast of which is composed of alluvial matter, or of the ordinary materials composing fossiliferous strata. The formation of a bay in the coast of an island situated like that of