Beports and Proceedings — Geologists' Association. 187 



Geologists' Association. — 1st March, 1872. — Professor Morris, 

 F.G.S., Vice-President, in the Chair.— 1, '•' On the Geology of Hampstead 

 (Middlesex)." By Caleb Evans, Esq., F.G.S.— The author described 

 the deposits which had been exposed from time to time during the 

 last few years in and near Hampstead. The principal excavations 

 noticed were the several drainage works near Child's Hill, . on 

 Hampstead Heath, and in Frognall Lane, and the tunnel on the 

 Midland Eailway under Haverstock Hill. It appeared from these 

 sections that the Lower Bagshot Sand which caps the hill passes 

 downwards into a dark sandy clay about fifty feet thick, abounding 

 with fossils, especially Voluta nodosa and Pectunculus decussatus. 

 The Pectuncidtis bed passes down into the London Clay of ordinary 

 character, which forms the lower part of Hampstead Hill. The 

 author noticed the great changes in physical geography which must 

 have taken place during the time that intervened between the 

 deposition of the Woolwich Series and that of the Lower Bagshot 

 Sand. He considered that remains of the Glacial deposits probably 

 exist on the north side of the hill. The position of these deposits 

 on an eroded surface of the London Clay showed the large amount 

 of denudation that had taken place prior to the Glacial epoch. The 

 author, in conclusion, directed attention to the existing valleys 

 around and to the north of Hampstead, which he considered had 

 been formed by means of the springs issuing from the water-bearing 

 Eocene sand and the Glacial gravels. — Mr, A. Bell thought the 

 leaf-beds of the Middle Eocene indicated freshwater conditions. — 

 Mr. H. Woodward considered the presence of XantJiopsis in these 

 beds evidence of marine or estuarine origin. He pointed out the 

 great value of the maps and sections exhibited by Mr. Evans. — 

 Professor Morris spoke of the foreign equivalents of the London 

 Eocenes, during the deposition of which great changes of level took 

 place. Though there are no traces of the Woolwich bed-s in the 

 Belgian area, these deposits are represented near Epernay in France, 

 while the London Clay forms a considerable area in Belgium. The 

 patches of London Clay on Salisbury Plain indicate the extension 

 of the Lower Eocene sea over that area, and Bracklesham species 

 are found at Chertsey. With respect to the Glacial deposits, the 

 Professor considered their importance to Middlesex very considerable, 

 and thought it not improbalDle that the towns of Barnet, Hendon, 

 and Finchley owed their origin to the presence of these deposits. 

 The physical features of the country north of Hampstead are 

 different from those south of that place, and this difference is due 

 to the Glacial deposits. Though the valleys of the district have 

 been formed, as we now see them, by the rivers, their formation 

 commenced during the rise of the land from the sea. 



2. " On a Eecently-exposed Section at Battersea." By John A. 

 Coombs, Esq. — This was a brief description of a section exposed 

 at the works of the London Gas Company now in progress near 

 Battersea. The Thames valley-gravels are cut through, and several 

 feet of the London Clay are exposed. The gravels, which show 

 much false bedding, yield mammalian remains, but the Gyrena 



