BARTON CLAY. 



n^ 



Phorus aggliitinans. Corbula pisum. 



Calyptra^a obliqua. Pholadomya, sp. 



Dentalium, sp. 



Ostrea flabellula Echinoderm. 



dorsata? 



Pecten corneus. Operculina, sp. 



Cardium, sp. Nummulina Prestwichiana. 



Lead-coloured clay, with few fossils - - - - 3 



Rostellaria macroptera. Corbula pisum. 



Dark sandy clay, with fossils (principally small bivalves) - 9 (> 



Rostellaria ampla. Area aviculma. 



Fusus regularis? Leda, sp. 



Pleurotoma exorta. Nucula, sp. 



Voluta nodosa. Cardium parile. 



Turritella imbricataria. Cardita globosa. 



Melania? Cultellus, sp. 



Calyptraea, sp. Corbula pisum. 

 Solarium plicatimi. 



These details of the lower beds are given to show how gradual 

 is the upward passaj^e, both lithological and palseontological, from 

 the Rracklesham Series, aheady described at p. 115, into the 

 overlying Barton Clay. 



When the original survey of the Island was made an inland 

 exposure of the Barton Clay was visible at Gunville. This is 

 now overgrown, and no new sections are at present open. The 

 Brick Yard at Gunville showed srhelly clay, from which were 

 obtained numerous sharks-teeth and some mollusca. Unfor- 

 tunately few of these have been preserved, and the new Brick 

 Yard on the west side of the road only shows Pleistocene Brick- 

 earth, resting on the upturned edges of the Lower Bagshot Sands, 

 with perhaps in one place a trace of the base of the Bracklesham 

 Series in some green sandy clay. 



At the east end of the Island the Barton Clay is seldom well 

 seen, owing to the accumulation of beach, and to the landslips 

 and mud-streams wliich constantly obscure this part o£ the cliff. 

 However in 1886 the sections were exceptionally clear and Mr. 

 Keeping was able to examine this part of the coast and to measure 

 the following section.* 



Section of the Barton Clay in Wldtecliff Bay. 

 (Measured by Mr. H. Keeping in 1886.) 



Ft. In. 

 Blue sandy clays, mth mottled brown patches of soft earthy 

 ironstone near the base. The upper 15 feet consist of bluish 

 sandy clay, containing - - - - - 50 



Terebellum sopitum, Brand. Calyptr^a trochiformis. Lam. 



Voluta humerosa, Edw. Ostrea flabellula,Lflm. 



Pyrula nexilis, Lam. Pecten carinatus, Sow. 



Natica, sp. , sp. 



* See Geol. Mag., dec. III. vol. iv. p. 70. 



