ALLUVIAL DEPOSITS. 52/ 



wall, have attracted much attention, and the beds have been described by De la 

 Beche, W. J. Henwood, J. W. Colenso, J. Carne, and others. The following 

 Section at the Fowey Valley Works was noted by Mr. S. R. Pattison : ^ — 



Ft. in. 



Peat 14 o 



Fine washed sand 2 6 



Peat, containing Hazel-nuts, etc., and antlers of Deer 4 6 



Sand and rounded stones, with much tin I ft. to 7 o 



Peat, containing numerous trees, etc 3 ^ 



Granite, on the surface of which large quantities of tin 

 were found. 



According to Mr. Ussher the Stream-tin beds may be about the age of the 

 'Head' (see p. 495), or formed during subsequent submergence. The Forest- 

 growth was of later date. 



Mr. P. O. Hutchinson has called attention to a Submerged Forest and to 

 a peaty-bed near Sidmouth.^ 



At Poole Harbour a Submarine Forest has been observed ; ^ and Peat has been 

 dug at Knighton Bottom, near Bournenioulh.* Peat also occurs in the Forest of 

 Woolmer.* Submarine Forests have also been noticed at Southsea and Ports- 

 mouth, « Bracklesham Bay, Pagham, Felpham, near Bognor, Pevensey Bay, and 

 St. Leonards ; '' and Peat occurs in the Lewes and Arundel levels. Scrobicularia- 

 clay occurs at Pagham Creek (now reclaimed), and at Lower Lancing, east 

 of Worthing. 8 (See p. 519.) 



In the Isle of Wight, at Tollands Bay, there is a lacustrine deposit containing 

 recent species of Helix, Cyclostoina, Siiccinea, Lhnncsa, Planorhis, etc.* 



At Romney Marsh and the Sussex Levels the whole of the Alluvium is below 

 the level of high-water at spring-tides, but the access of the sea is prevented by 

 tracts of shingle bordering the marsh, which are partly piled above the level of 

 high water, and by artificial banks which have been erected where no natural 

 barrierof shingle exists.''' 



Cervus megaceros, Bos primigenius, etc., have been met with in the Alluvial 

 deposits of the Kennet Valley.'^ Near Newbury the peat has been dug for fuel, etc. 

 The following section of the beds was noted by Prof. T. R. Jones : — 



Alluvium. 



Shell-marl, called 'malm,' with freshwater Mollusca, I in. to 8 ft. 



Peat, 10 ft. in places. 



Shell-marl, with remains of Beaver, etc., i or 2 ft. 



Gravel. 



In the immediate neighbourhood of London, the Alluvium of the Thames valley 

 does not occupy a very large area, but much of the land formed of it south of the 

 river at Lambeth and Kennington is but little above the Thames high-water mark, 

 and in Bermondsey parish there is land below this level. A considerable thickness 



' Trans. R. Geol. Soc. Cornwall, vii. 34 ; this and many other sections are 

 given in a paper by W. A. E. Ussher, Post-Tertiary Geol. Cornwall, 1879, pp. 

 27, 32,44; G. Mag. 1879, p. 251. 



2 Trans. Devon Assoc. 1873 ; Nature, Oct. 21, 1880, p. 584. 



^ Lyell, Principles of Geology, edit. xi. ii. 536. 



* W. B. Clarke, Proc. G. S. ii. 599. 



5 White, Nat. Hist, of Selborne, ed. by Bell, vol. i. p. 17. 



® Sir H. James, Q. J. iii. 249. 



'' Mantell, Geol. Sussex, p. 288 ; Dixon, Geol. Sussex, ed. 2, p. 146. 



^ Dixon, Geol. Sussex, ed. 2, p. 81. 



* Trimmer, Q. J. x. 54 ; Bristow, Geol. I. of Wight, p. 98. 

 '" Drew, Geol. Romney Marsh (Geol. Surv.). 



" Geol. Hist, of Newbury, 1854, p. 40; Geologist, v. 317. 



