BEACHES, ETC., OE THE SOUTH OF ENGLAND. 281 



exist at Moiisehole, St. Loj^ Cove, Whitesand Bay, Pornarvon Cove, 

 Forth Just, Priest's Cove, Cape Cornwall, Perth Ledden Cove, Greeb 

 Tor, Pendeen Cove, Carrack Ola Point, Treeii Cove, and Porth- 

 ywidden Cove, St. Ives (see Map, PI. YIII.). 



The Raised Beaches round the Land's End vary from 4 to 15 

 feet in thickness, and are from 5 to 15 feet above high-water mark. 

 They consist of pebbles of quartz, granite, slate, and greenstone in a 

 granitic sand, together with round and subangular boulders of the 

 same local rocks — some being as much as 2 feet in diameter, — and 

 a few small, subangular chalk-flints.^ Shells are rare, except in a 

 comminuted state. The overlying Head is from 10 to 60 feet thick, 

 and consists of angular fragments of the adjacent granite, slate, 

 greenstone, and hornblende-rocks, with angular blocks of the same 

 (of considerable size) embedded in a light brown loam. Mr. X. 

 "Whitley gives the thickness of the Head between !N"ewlyn and 

 Mousehole at 40 feet. The slope of it is so gradual, in comparison 

 with the slope of the hill, that it would have originally extended 

 300 feet beyond its present base. 



(16) The North Coast of Cornwall and Devon. — On the east of 

 St. Ives Bay a Raised Beach extends from Gwythian to Godrevy. 

 The beds vary much in thickness, the Head being in some places 

 15 feet thick, and the Beach is about 5 feet above high- water mark. 

 A sketch of Mr. Ussher's, from which the following diagram (tig. 7) 

 is reduced, shows that the Head here reached to a rock, 210 feet 

 distant from the shore. 



Pig. 7. — Diagram of Godrevy Beach (' Godfrey ' in map). 



y^ 



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feet 



a. Head of angular fragments 5 to 10 



b. Grey and brown (blown?) sands, dipping inwards 10 to 16 



c. Beach, with slate fragments 1 to 5 



There is a fine example of a Raised Beach in Pistral Bay, near 

 New Quay. It extends along the bottom of the Bay, where it is 

 only a few feet (6 to 10) above the level of the present beach, to 

 the headland at the southern end, where it rises to a height of 

 between 20 and 25 feet. Pig. 8 (p. 282) is a section taken near 

 the centre of the Bay. 



^ Mr. N. Whitley estimates the relative proportions of the pebbles iu the 

 Kaised Beach near St. Ives at : — 



Hornblende-rock 20 



Granite 15 



Quartz 6 



Chalk-flints 2 



V2 



