196 Mr. S. V. Wood on the Red Crap 



they repose on the Chalk, while in the south-eastern area they 

 repose, in the condition of gravels, on the London Clay. The 

 southern boundary of this formation may be indicated in some 

 parts with such precision that it can with certainty be averred 

 that this was the shore in this direction of the bay of the period. 

 Along the coast south of the Stour, the denudation has in many 

 places removed this formation, leaving the London Clay to form 

 the coast-line — the lower Drift appcai'ing a few miles inland, 

 and furnishing outliers occasionally nearer the coast. Ranging 

 south as far as Chelmsford, its southern edge may be traced 

 crossing the railway-cutting a few furlongs south of Chelmsford 

 Station, from which place it extends eastward to Danbury Hill, 

 where it forms an outlier, apparently nearly 100 feet in thickness, 

 resting on London Clay. Between those two points it occurs at 

 the villages of Badow and Sandon. West of Chelmsford, it passes 

 by Writtle, and, a mile north-west of that place, is lost under the 

 Boulder-clay, a deep section being exposed at that place about a 

 furlong only from its disappearance under the overlying Clay 

 Drift. From that point to Badow, the margin of the bay depo- 

 siting the beds may be indicated with certainty; but east of 

 Badow its boundary-line has been destroyed by the great denu- 

 dation that has removed the Bagshot gravels and the upper beds 

 of the London Clay. The precise margin alluded to is shown 

 in this way. At intervals over Southern Essex, the Bagshot 

 sands and gravels, that originally extended, for a thickness of 

 about 50 feet, continuously over the London Clay, now^ remain 

 as outliers on the summits of the higher hills, as at Raleigh, 

 Galleywood, Langdon, Stock, Margaretting, Warley, Shenfield, 

 South Weald, Epping Forest, &c., uncovered by any Drift-beds, 

 the upper or Clay Drift having been removed from them, while 

 the tablelands that range from Brentwood towards Epping on 

 the one hand, and towards Ongar and the Rothings on the other, 

 are capped by these Bagshot beds, covered with patches of the 

 upper or Clay Drift, without the faintest trace of anything re- 

 sembling the lower-Drift deposit between them. 



These Bagshot beds possess so uniform a character, both in 

 their constituent material and thickness, and are so evenly and 

 uniformly covered by the Drift clay in immediate contact with 

 them, where that remains undenuded, that the idea of any ex- 

 tension of the lower Drift over this area, during the interval 

 between the two formations, is precluded. In addition to this, 

 the lower Drift, wherever it occurs, has invariably eroded the 

 whole of the Bagshot beds, so that it rests on the London Clay 

 only. This process is conspicuous near Chelmsford : there the 

 Drift gravels may be seen resting on the Ix)ndon Clay, while, 

 within the distance of a mile, the complete beds of the Bagshot 



