On some Intrusive Igneous Rocks in Cawsand Bay, near Plymouth

Abstract

Several of the principal features in this locality are described by Sir Henry De la Beche, in his “Report on the Geology of Cornwall, Devon, and West Somerset;” but the plan of that work was, of necessity, limited in a great degree to general views. To have entered into detailed descriptions of local phaenomena, in so large a field, would have required the labour for many years of several observers in the investigations, and the results would have filled many volumes of description. The author of that Report has however dwelt upon many of the more remarkable places where the phaenomena throw light upon important questions of theory; but, in these days, when geological researches demand far more minute observation, when, as our President has on more than one occasion inculcated, the ground must in many cases be gone over inch by inch, ample opportunities will long remain for diligent observers to fill-in details in the masterly outlines of the geology of the West of England, which have been drawn by the skilful and practised hands of De la Beche, Sedgwick, and Murchison. Devon, and West Somerset;” but the plan of that work was, of necessity, limited in a great degree to general views. To have entered into detailed descriptions of local phaenomena, in so large a field, would have required the labour for many years of several observers in the investigations, and the results would have filled many volumes of description. The author of that Report has however dwelt