32 CORNISH POST-TERTIARY GEOLOGY. 



He adds : " As every part of this deposit, wrought during the 

 memory of the generation now passing away, was beyond high- 

 water mark at Forth, and even above the level of the Kaised Beach 

 at Fistral, near New Quay, it contained neither shell nor other 

 substance of marine origin, but frequently afforded granules of 

 gold." The shelf consists of clay slate. 



If De la Beche was not misinformed, we must suppose that the 

 Treloy Valley was excavated j^rior to the formation of the Raised 

 Beaches, or that the occurrence he describes occupies a very different 

 site from Mr. Henwood's section. If, however, it lay below high- 

 water mark, we might be justified in considering its formation as 

 subsequent to the submergence of the forests, and refer the tin 

 ground in this valley to a still more modern date. 



sub:\ierged forests. 



Looe. 

 Mr. Box ' noticed the exposure of oak, alder, ash, and elm trees 

 under sand and shingle, below high-water mark, on Millendreath 

 Beach, east of Looe. The trees were imbedded in compact peat, 

 chiefly composed of marsh plants. 



Foicey. 

 Mr. Peach - states " that portions of trunks and roots of trees, in 

 situ, were exposed at Ready Money, in Fowey Harbour, by a heavy 

 gale of wind ; they were rooted in a stiff clay over which leaves, 

 flags, etc., and the elytra of beetles, are found." 



PorthneUia (near Ilevagissrj). 

 Mr. Peach ' observed roots and parts of stems of trees, in situ, on 

 clay, surrounded by alluvial matter containing flags and the elytra 

 of beetles, on Porthmellin Beach, after a heavy gale. 



Fahaoutli. 

 Mr. E. Claypole ^ notices the occurrence of peat, seldom exposed 

 except at spring-tide low- water, and after heavy south-easterly gales, 

 in the curve of the shore at Gyllyngvaes, Falmouth. The peat 



' Twenty-sixth Ann. Rep. Roy. Instit. Corn, for 1844. 



2 Trans. Roy. Geol. Soc. Corn. vol. vii. p. 12. ^ zbid. vol. vi. 



* Proc. Rrist. Nat. Soc. vol. v. p. 3<5, lor 1870. 



