1916.] THE PLEISTOCENE PERIOD. 343 



The extremes of elevation of the different deposits are 

 23 feet and 30 feet, measured at the centre of the separate 

 deposits. The thickness averages 4 feet with extremes of 

 6 feet and. 8 feet. 



An example of one of the deepest deposits is to be found 

 at Jethon, on the part of the island which faces Herm. 



I show a photograph, taken by Mr. Leale, expressly for 

 this paper. (It is marked No. 1 in the illustrations.) 



The deposits of this beach in Guernsey are very numerous 

 and situated as follows : — 



East Coast. — At St. Martin's Point and along the cliff to 

 Divette, the beach deposit is found, with but slight breaks, 

 underlying the cliff head. (See photographs 2 and 3.) Here 

 the beach is only a thin line of pebbles and constitute the last 

 remaining remnant of former extensive benches. At Fermain 

 Bay, North point, the deposit is thicker, but from there to the 

 Vallette only small and easily missed patches are met with. 

 Under High Street, at the end of the Arcade, there is an 

 extensive deposit which was exposed to view when the Arcade 

 was repaved. From the Town to the Longstore excavations 

 have proved that the beach, at one time, covered a large area. 

 This is not now visible. The old sea line, hence washed the 

 land below the Cotils. A. remnant, protected so far from 

 sea erosion by an out-crop of rock is visible a short distance 

 north of the Longstore, and by further deposits Ave trace 

 the old beach line inland along the Bouet Boad, losing 

 it not far from the mill at the lower level. We find 

 it again at Barker's quarry and again at Spur Point. I 

 have not met with any deposit on the East margins of the 

 Braye-du-Valle, but around the coast of Bordeaux harbour 

 and the adjoining hommets the beach is strongly in evidence. 

 The beach continues around the Fort Doyle promontory, and 

 on reaching the North of l'Ancresse it brings us to its largest 

 remaining deposit at Fort Le Marchant. This beach demands 

 a description of its own. 



Although there is but a small portion of the beach 

 originally deposited here, it nevertheless is a most extensive 

 example of the beach of this elevation. It is now about 

 1,000 yards in area and occupies the whole of the low ground 

 between the Catellaine hill and the Fort. It is fast being 

 eaten away by the sea which, as soon as its work is ended, 

 will separate the Fort from the land. The erosion is so rapid 

 here that the sea is mixing the old beach material with the 

 new so as to be distinguishable w r ith difficulty. The section 

 exposed is about four feet in thickness as an average, reaching 

 eight feet on its landward limit. (See photograph No. 4.) 



