Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/437



No. 1 is a view of the small port and beach of the Creux in the Isle of Sercq, exhibiting the gate of the Tunnel, through which is the only entrance into the island. The adjacent rocks are of trap, and in the distance is seen a detached mass of granite.

No. 2 is a view of the Coupée in the Isle of Sercq, taken from the smaller division of the island, called Petit Sercq. That part of the isthmus, the furthest from the spectator, is traversed by the soft vein mentioned in the Memoir, and is rapidly wearing down.

No. 3 represents one of the granite veins in Port des Moulins in the Isle of Sercq. The grauwacke has been washed away; and part of the granite itself, from the effects of rifts and decomposition, has fallen down; thus making a kind of rude door-way through the vein.

No. 4 is a general view of Port des Moulins. The rocks on the right hand are of grauwacke-slate, as also are the three insulated buttress-like rocks that appear in the distance. Behind the two furthest of these is situated the granite-vein represented in Pl. 3 : the steatitical vein described in the Memoir lies also among the distant cliffs.

No. 5 is a view of Fourchi Point in the Isle of Alderney, representing the great fracture in the porphyry rock, of which this headland is composed. The open sea is the passage called the Race of Alderney, and Cape la Hogue is seen in the distance.