﻿MURCHISON FLINT DRIFT OF S.E. ENGLAND. 



383 



near Yalding Station, capping a small elevation of Lower Greensand 

 (Neocomian). 



The arrangement of the drifted materials also shows, that the waters, 

 whatever they were which translated them, acted in an opposite di- 

 rection to the present Medway ; for in proportion as you approach to 

 Maidstone and the North Downs, the fragments of flint become larger 

 and much more abundant. 



In cutting the line of the Dover Railroad from Tunbridge to Folke- 

 stone, various other heaps of drift were removed from the surface of 

 low domes of the Weald-clay on which they had been arrested, as at 

 Marden, Headcorn, Pluckley, &c. At Marden, and at about a 

 quarter of a mile east of the station, the excavations made in the sum- 

 mit of a low dome are still to be seen, whence much brick-earth or 

 loamy clay, with a thick mass of shingly gravel, chiefly the detritus 

 of the Lower Greensand hills, were abstracted from the surface of 

 the Weald-clay for the construction of the railroad. The teeth and 

 defences of a Mammoth were found here under about 1 5 feet of this 

 detritus*. The position of these remains at a height of about 70 

 feet above the river Beult or its tributaries, renders it impossible to 

 suppose that they were accumulated under the silt and gravel of any 

 stream which did not extend over all the lower country between the 

 hills of Lower Greensand on the north and those of the Hastings sands 

 on the south. Here also, as at Pease Marsh, the remains were found 



species, we might then suppose, that at the period when the sea formed the Brigh- 

 ton pebble-heds, it entered up an estuary as far as Aylesford ; which at this day 

 is very little above the influence of high spring-tides. This subject calls for elu- 

 cidation. The Pholades may, however, have belonged to an early tertiary or older 

 period, and thus prove alien to the present subject, an opinion to which I incline, 

 because the beds affected by them are separated from the flint-drift by a band of 

 mud-like loamy silt, in which many fragments of shells of the Lower Greensand 

 occur. I willingly leave this subject in the hands of Mr. Prestwich, to whom 

 Mr. Bensted has also indicated the above-mentioned curious phenomenon, and 

 who has been occupying himself for some time in the study of the superficial de- 

 tritus of Kent. When the remains of Hycena were found many years ago in fis- 

 sures of the Maidstone Grit by Mr. Braddich, at Boughtou Malherbe, six miles 

 S.E. of Maidstone, I visited the locality in company with Dr. Buckland and other 

 geological friends. Whether the cavities in which the bones occurred were really 

 at any time inhabited caves, as our able and zealous leader wished to prove, or 

 were simply a portion of the drift so often alluded to, I have a distinct recollec- 

 tion that the bones had been preserved under a copious accumulation of imper- 

 vious loam and clay, which had spread over the orifices and plugged them up, at 

 considerable altitudes. Mr. Bensted has since informed me that in some of the 

 cavities of his quarries, 150 feet above the Medway, fossil bones have also been 

 found under great masses of similar drift. The chief localities where fossil Mam- 

 malia occur in this part of Kent have, indeed, been clearly described by Mr. Mor- 

 ris (Loudon's Mag. Nat. Hist. vol. ix. p. 593, 1836) ; and this good naturalist 

 informs us that the species of shells {Helix hispida, Pupa marginaia, and Succinea 

 oblonga), found usually in the upper (loamy) portion of the detritus, belong to 

 land Testacea, and to such as " inhabit the banks of rivers and marshy places, no 

 decidedly freshwater shell having yet been detected ; " whilst the large fossil 

 bones lie in the lower mass and under the clay. — [Added when the Memoir was 

 in type, October 1851.] 



* Although the author previously knew of gravel overlying the Weald-clay at 

 Marden (South-Eastern Railway), he only heard of the fossil bones found there 

 since the Memoir went to press. — R. I. M. 



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