Extract

The few following notes may help to explain the maps on which I have sketched the leading features of the mineralogy of the Channel Islands. The specimens which I collected having been mislaid, I am unable to give a more particular description of the, stones which I have noticed.

These islands are situated in St. Michael’s Bay, and from the general direction of the land, the form of the bottom, and the numerous rocks which are scattered around, may possibly have once been more intimately connected with the Coast of Normandy. Of this however any further evidence, arising from continuity or similarity of strata, is, for the present at least, inaccessible.

It will be seen that they are chiefly formed of granitic rocks. The Islands of Chozè, which lie deeper in the Bay, are of similar formation, and I am informed that Mont St. Michel is also a mass of granite. Excepting this, I have not been able to obtain any information with regard to the Coasts of Normandy or Brittany, from the Islands of Brehat to La Hogue. But from the Seven Islands to l’Isle de Siecle, including Morlaix and Treguier, I have had opportunities of ascertaining that granite is the predominant rock; and more extensive observation may possibly prove, that a chain of granitic rock extends from Cape La Hogue to Ushant, a line parallel to that granitic chain, which rans in a WSW direction, from Dartmoor to the Scilly Islands. This is rendered further probable, from the