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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



flints, the latter large and often but little rolled. The whole mass be- 

 comes also more irregular and variable, which, with its more shingly 

 and coarser character, indicates a nearer approach to the source from 

 whence these portions of the materials of this division of the Lower 

 Tertiaries were derived. The exhibition, however, of these Lower 

 Tertiaries throughout this district is very imperfect and unsatisfac- 

 tory *. 



If now we proceed northward from the Isle of Wight, we find that 

 beneath Southampton the beds between the London clay and the 

 Chalk consist essentially of mottled clays about 80 feet thick f. At 

 Fareham the railway cutting exposed a good section of bright red 

 mottled clays and the London clay with its fossiliferous Basement-bed 

 above them. At the outcrop of this group at Kembridge, between 

 Romney and Salisbury, we fiiid the only instance I am acquainted with 

 in the Hampshire Tertiary district of a character common to these beds 

 in the western part of the London district, viz. the occurrence of a 

 band of the " Ostrea Bellovacina " in a bed of greenish sand imme- 

 diately over the chalk and beneath the mottled clays J. The follow- 

 ing is the section taken from my former paper (Journ. Geol. Soc. 

 vol. iii. p. 360) : — 



Fig. 1. — Railway -cutting, Kembridge. 



Feet. 



1. Flint-gi-avel 2 to 8 



b. Mottled red, grey, and yellow clays 15 



a. Clayey yellow or greenish sand, with an underlie of the Ostrea Bellovacina 



and green-coated flints 4 



4. Chalk 6 



At Clarendon Hill the strata are very similar to those at Alum 

 Bay, but they are reduced in thickness to about 45 feet, and contain 



* One of the best sections near Dorchester is at Yellowham hill, on the Bland- 

 ford road. 



+ The^ section of these beds at the Artesian well of Southampton, as noted by 

 Mr. R. Keele, is as follows :— " These mottled clays were remarkable from the 

 almost entire absence of sand or water throughout the whole formation. No 

 organic remains were found or indications of lignite. The clay was of extraor- 

 dinary purity and hardness, and of almost every variety of colour. The last 6 or 8 

 feet of the lowest beds were of less degree of purity, the clay being mixed with a 

 coarse flinty sand as they approached the main bed of chalk ; the last 5 feet of 

 the bed was of a dark green colour, and mixed with water, with black flint, pebbles, 

 and very coarse sand, all strongly tinted with the dark gi-een colour above-men- 

 tioned." 



t There is probably some other locaUty near Salisbury where this shell occurs, 

 as the 0. undulata figiu-ed by Sowerby from the neighbourhood of that city is 

 apparently the O. Bellovacina of the Tertiary beds. 



