16 Dr. MacCulloch's Account of Guernsey, 



nodules rudely approaching to ocular agates. These are accompanied 

 by veins of mica and felspar in various states of decomposition, appa- 

 rently from the failure of the mica, and by veins of chlorite con- 

 taining here and there pyrites, together with talc and quartz, and 

 talcaceous schistus, and a mixture of greenish steatite, felspar, and 

 quartz. The rocks here also are of trap formation, and the beach is 

 covered with jaspideous pebbles as at Havre Gosselin. 



Such is Grande Havre, and the number of the soft veins here 

 existing may serve to account for the great waste the land has under- 

 gone. The Coupee is becoming daily lower to the eye. 



The southern point of the island is formed of a sienite, but there 

 is no opportunity of tracing its connexion with the trap of the 

 western shore; for, from the Coupee to I'Etat there is no access, 

 unless under circumstances of weather which rarely occur. 



The Etat very much resembles in shape the Mewstone of Plymouth, 

 and from its appearance and inclination is probably of the same for- 

 mation as that I have been describing. The felspar of the sienite 

 is invariably white, and not nearly so beautiful as that of Guernsey 

 before mentioned. It is intersected by various trap veins, one of 

 the most remarkable of which near Paregorois runs N and S, in- 

 clining about 3° to the W, and is about six feet in thickness. This 

 vein consists of trap porphyry and amorphous trap ; and besides these, 

 regular hexangular blocks, the sides alternately large and small, are 

 quarried out of it. I was unable to find in what position they lie, 

 as the vein was only accessible at low water, but from what I ob- 

 served in a similar vein at Experquerie, I am inclined to think that 

 the columns lie across it. Their joints are fiat. Some veins of a 

 brick red felspar are also here to be observed, and in some places the 

 sienite passes into greenstone ; but as this part of the coast is almost 

 inaccessible, it is difficult to say what varieties may exist in it. The 



