78 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



The series of local sections forming the diagrams A, B, & C, PI. I. 

 have been arranged with a view to show the original structure and 

 sequence of the beds of the Woolwich and Reading series, and of the 

 other two divisions of the Lower London Tertiaries at the commence- 

 ment of the London Clay period, as also to prove the correlation of the 

 strata, and to render apparent the remarkable changes of lithological 

 character which the strata undergo in their range from Wiltshire to 

 the coast of Kent. These sections are either described in the text, 

 or in the explanation of plates ; whilst a few others, which possess 

 features which those sections do not embrace, are given in separate 

 figures. 



§ 1 . Range and General Physical Features of the " Woolwich and 

 Reading series." 



Throughout the Isle of Wight and the western portion of the 

 London Tertiary district, this middle group consists of unfossiliferous 

 mottled clays passing into or alternating vdth non-persistent sands : 

 as it approaches near to London, strata of laminated and carbonaceous 

 clays, sands more calcareous, and thick shingle beds of flint pebbles, 

 with fluviatile and sestuarine shells, set in and replace the mottled 

 clays. Following the group still further eastward we find it gra- 

 dually becoming less pebbly and argillaceous, and at last passing en- 

 tirely into light-coloured pure quartz ose sands mixed with more or 

 less green sand, and containing in i i s extreme eastern range a distinctly 

 marine fauna. Viewed horizontaJy this middle division may there- 

 fore be divided into three distinct areas of — 



W. C. E. 



Sands and Mottled Clays. Pebble beds, Sands, and Quartzose and Glauconi- 



(Eeading and the Isle of laminated Clays. ferous Sands. 



Wight.) {Woolwich, Blackheath, and (^HerneBayand Canterbury .) 



Bromley.) 



These lithological changes are effected in an east and west direction 

 in both the London and the Hampshire districts. In the latter, 

 the last (E.) form of structure is only partially developed. It exists a 

 few miles east of Newhaven, and, with the second, is well exhibited 

 in an outlier on the coast three-quarters of a mile south of that town. 

 The latter shows again at the west of Brighton, but there merges 

 into the first (W.) form, which is continued by Lancing and Arundel to 

 Botley near Winchester, in a narrow belt marked by its generally 

 well-wooded surface, and by a succession of villages. These beds then 

 pass two miles south of Salisbury, thence a few miles north of Ware- 

 ham to near Dorchester, becoming more sandy as they proceed west- 

 ward. Returning along their southern outcrop they pass by Lul- 

 worth to Studland, and in the Isle of Wight range, as is well 

 known, through the centre of the island from Alum Bay to White 

 Cliff Bay. 



Throughout its northern range this division only occasionally pre- 

 sents any marked surface-features, and the sections are small, indi- 

 stinct, and far apart. On its interrupted southern outcrop the ver- 

 tical position of the strata restricts them to within so narrow a band, 

 that they can rarely be seen except in the coast sections. 



