QUATERNARY PHENOMENA IN THE ISLE OE PORTLAND ETC. 29 



2. Notes on the Phenomena of the Quaternary Period in the Isle 

 of Portland and around Weymouth. By Joseph Prestwich, 

 Esq., F.R.S., Y.P.G.S., &c. Professor of Geology in the Uni- 

 versity of Oxford. (Read June 10, 1874.) 

 [Plate I.] 



In their well-known paper on the Geology of Weymouth, Buckland 

 and De la Beche * give but a very brief notice of the Quaternary beds 

 of the district. They observe that there are no very " extensive and 

 continuous beds of gravel," and that " the largest deposit of diluvium 

 we have noticed is at Upway Street, four miles north of Weymouth ; 

 but in smaller quantities and irregular patches it is disposed over the 

 whole surface of the country, on the summits and slopes of the hills 

 as well as in the valleys." These scattered drift-beds are all referred, 

 as usual at the time, to one great inundation, which excavated the 

 valleys and overspread the country with patches of diluvial gravel. 



Mr. Bristow, in 1850 f, recorded the presence on the top of the 

 cliff at Portland Bill of a recent conglomerate, which Mr. Weston 

 in 1852 X described as a u marine shingle," consisting " of beach- 

 pebbles (with a few chalk flints);" and in 1860 Mr. R. Damon § 

 mentioued that it contained in places " numerous shells of species 

 now living in the neighbouring sea." 



Mr. Whitaker || was the first to give, in 1869, a more particular 

 account of this beach, and to specify the occurrence of Littorina 

 litorea, L. littoralis, Patella vulgata, and Purpura lapillus, extend- 

 ing on the east side of the Bill for a distance of half a mile north- 

 ward. Over the beach Mr. Whitaker noticed near " Cave Hole " 

 the presence " of a head " (the waste of Purbeck and Portland beds) 

 consisting of pebbles of limestone, flint, and chert ; and at another 

 place, of a yellowish brown loam with " Bithinia and Pupa" 



In 1870, Mr. Pengelly pointed out the occurrence, in this raised 

 beach, of Budleigh-Salterton and " granitoid " pebbles, and gave a 

 list of seven shells %. 



With respect to the occurrence of mammalian remains, the only 

 specimen mentioned by Dr. Buckland** as having been found in this 

 district was the tooth of an elephant, picked up on the Chesil Bank. 

 The first notice of such remains in Portland was made in 1852 by 

 Mr. Nealeft, who states that fragments of bones and teeth had been 

 found about 400 feet above the sea-level, in a superficial deposit, red 

 at top and passing into a black sand with large round black blocks 

 of stone. The only species named is " horse ;" but I find that Mr. 



* Trans. Geol. Soc. vol. iy. 1836, p. 44. 



f Geological-Survey Map. 



| Quart. Journ. Geol. Soc. vol. viii. p. 1. 



§ Geology of Weymouth, and the Island of Portland, p. 141. 



|| The Geological Magazine, vol. vi. p. 438. 



<j[ Trans. Devonsh. Assoc. Sc. Lit. & Art, 1870. 

 ** Op. cit p. 44. 

 ff Quart. Journ. Geol. Soc. vol. viii. p. 109. 



