﻿MURCHISON FLINT DRIFT OF S.E. ENGLAND. 363 



of the well-known case at Newhaven, and one which will afterwards 

 be mentioned, the overlying Plastic-clay with its grey-wether-sand- 

 stone and rounded pebble beds, has either been swept away, or so 

 re-aggregated and mixed with a tumultuous drift of chalk-flints, for 

 the most part angular, that it can nowhere be said to be in situ. 



The slopes of the Chalk Hills on either side of the Valley of the 

 Ouse, where they approach to the coast, are here and there laden with 

 considerable thicknesses of the Clay, whether to the west of Seaford 

 or to the east of Newhaven. In many spots the clay merges into 

 loam, in parts quite sandy ; in general the tint of the re-aggregated 

 mass is rusty brown and ochreous, owing to a copious dissemination 

 of iron-ore. 



The cliffs exposed to the action of the sea afford numerous sections 

 (as seen in the works of Mantell), where the drifted materials enter 

 far into crevices and holes in the White Chalk. In the district com- 

 prising the villages of Rottingdean, Falmer, and Stanmer, there are 

 abundant proofs of this infilling of the surface of the chalk, of which, 

 indeed, the cuttings of the railroad from Lewes to Brighton afford 

 numberless examples, some of which, when carefully examined, may 

 be found to pertain to the older tertiary period ; though I think these 

 will prove to be rare exceptions. At Rottingdean, the manner in which 

 the angular flint-drift has been swept into the little combe in which 

 the village stands, and where it forms a coagulated mass extending 

 to the sea-front, at once explains, in my opinion, the origin of the 

 East Sussex word " Combe Rock," first used geologically by Dr. 

 Mantell. That author* has rendered the cliffs of Brighton classical 

 by his faithful and lively delineation of this " Combe Rock " or 

 " Breccia," which he also termed the " Elephant Bed," from finding 

 in it abundant remains of these and other extinct mammals. 



If, however, in addition to the chalk-flints, we substitute tertiary 

 debris for the fragments of the Lower Greensand, such combe-rock 

 is quite analogous to the " flint-rag" of the Weald already described. 

 A large part of the town of Brighton is built on it. This breccia 

 is there made up of chalk- and flint-detritus, mixed in some parts 

 with sand, in other parts with stiff plastic-clay, and in others with 

 loam. When Dr. Mantell wrote his earlier works, cliffs of this 

 ancient concrete were visible, resting on ledges of solid chalk, and 

 extending from the Steine to Kemp Town : these I have formerly 

 examined, but they are now built up with artificial concrete to prevent 

 subsidence and decay. To the east, however, of this grand parapet, 

 i. e. immediately beyond Kemp Town, the natural features remain 

 well-exposed. They can still be thoroughly examined by walking on 

 the shingle from the end of the Terrace at Kemp Town under the 

 natural cliff (70 to 80 feet high) to the flag-staff of the Preventive 

 Station. There, at the base of the cliff, the white chalk with some 

 flint is in situ, and lies in strata which, although nearly horizontal, 

 rise a little towards the east, so as to be about six feet above the 

 higher shingle of the shore. 



* See ' Geology of Sussex,' p. 277 et seq., and plates 4 and 5. 



