60 GEOLOGY OF THE ISLE OF WIGHT. 



mentary detritus, composing the south-eastern 

 portion of England, are separable into four well- 

 marked natural groups or formations. 



I, The drift, or Alluvium and Diluvium. — 

 These are the uppermost or superficial deposits, 

 and consist of irregular layers of waterworn and 

 drifted materials, containing the skeletons of extinct 

 species of colossal herbivora — as the mastodon, 

 mammoth, rhinoceros, hippopotamus, elk, deer, &c, 

 and in certain localities of the remains of Carni- 

 vora, Rodents, &c, some of extinct, and others of 

 species still existing in these islands. These beds, 

 which rarely exhibit indications of tranquil depo- 

 sition, are heterogeneous layers of debris, winch 

 have either been transported by the sea, or by 

 river currents, or by floating ice, or driven by 

 waves of translation occasioned by elevations of 

 the bed of the ocean, into estuaries, bays, and 

 creeks. 



II. Tertiary eocene* formation of the 

 London basin. — This series is chiefly composed 

 of layers of stiff, dark bluish-grey clay, abound- 

 ing in marine shells, and having strata of sand 

 mid gravel in the upper part, and sand, gravel, and 

 mottled clays in the lower part, with freshwater 



» Eociv , a term applied by Mr. Lyell to the earliest tertiary formations. 

 MedaU of Creation," vol. i. 



