EOCENE. 



427 



EOCENE. 



u ^ 

 o 



The Eocene strata have been divided as follows : — 



i . 



Upper Bagshot Beds. 



Middle Bagshot Beds, j ^^^^^x^^^m Bed 



Upper 

 (Oligocene' 



Middle. 



Fluvio-Marine Series of the Isle of Wight and 

 Hampshire. 



Upper Bagshot Beds. j Bartonian. 



Barton Clay. )^ 



.Lower Bagshot Beds. 



'London Clay and Bognor Beds (Upper London 

 Tertiaries). 

 Lower. -! Oldhaven and Blackheath Beds. ^ Lower 

 Woolwich and Reading Beds. \ London 

 Thanet Beds. J Tertiaries. 



The strata are on the whole conformable, but there are evidences 

 here and there of local, and, probably, contemporaneous erosion. 

 Our knowledge of these divisions is chiefly due to the researches 

 of Prof. Prestwich. 



The Eocene strata are characterized by living families and 

 orders of Mammalia ; among living genera is that of the Opossum 

 {Diddphvs). From the occurrence o{ Palccothcrium the term Palseo- 

 therian was used by John Phillips for this series.^ 



LOWER EOCENE. 



THANET BEDS. 



The name Thanet Sands was given by Prof. Prestwich in 1852, 

 from the fact that the beds are best exhibited in part of the Isle of 

 Thanet and adjacent country.^ 



The series consists of pale-yellow quartzose sand and loam, with 

 sometimes greenish particles ; so that in places it becomes an 

 impure argillaceous greyish greensand. A marked feature is the 

 occurrence of green-coated flints at the base of the deposit, resting 

 on the Chalk. The thickness of the beds is variable; under 

 London it is about 20 feet, in West Kent upwards of 60 feet. 



1 For figures of fossils see Monographs of the Palreontograph. Soc. ; Eocene 

 Mollusca, by F. E. Edwards and S. V. Wood ; Crustacea, by T. Bell ; Reptilia, 

 by R. Owen and T. Bell, etc.; Plants, by J. S. Gardner and Baron C. von 

 Ettingshausen ; see also Lowry, Chart of British Tertiary Fossils. 



2 Q. J. viii. 235. 



