286 Geological Society : — 



sequence between the pre-glacial drifts and the earliest post-glacial 

 drifts of the valley, which is probably covered by the extreme glacial 

 epoch. It was a time of erosion, rather than of deposition in this 

 area. Of the earliest drift of the Darent valley, little has escaped later 

 denudation. The bank of coarse gravel on the hill on the west side of 

 the valley between Eynsford and Earningham, certain flint-drifts 

 in the upper part of the valley, and a breccia of chalk-fragments on 

 the hill west of Shoreham, may be referred to this period. 



iv. The High-Level or Limpsfield Gravel Stage. — The gravel at 

 Limpsfield occurs on the watershed between the Darent valley and 

 the Oxsted stream, but the author agrees with Mr. Topley that the 

 gravel belongs to the Darent system, and Westheath Hill may be 

 part of the original ridge separating the two valleys. This gravel 

 is post-glacial, and the denudation of the area had made considerable 

 progress at the time of its formation, for the Chalk escarpment rises 

 200-300 feet, and the Lower Greensand 100-200 feet above the 

 gravel-bed. The author traces outliers of this gravel down the 

 valley at lower and lower points to the Thames valley at Dartford, 

 and correlates it, not with the high plateau-gravel, but with the 

 High-level gravel of the Thames valley, and shows that its com- 

 position indicates that it is derived from the denudation of the Chalk 

 and Tertiary beds. Mr. A. M. Pell has discovered numerous imple- 

 ments in it, mostly of the smaller St. Acheul type, and the author 

 hopes that they will soon be described by their discoverer. These 

 implements agree in general type with the " Hill group" of the Shode 

 valley, and not with the older group of the Chalk plateau, or those 

 of the lower levels of the Thames and Med way. 



v. Contemporaneous Drift of the Cray Valley. — Implements of this 

 age have been found by Mr. Crawshay and by Mr. P. Norman, near 

 Greeu Street Green, in gravel which is more than 100 feet below the 

 Red Clay of the plateau. 



vi. Brielc-eartlis of the Darent Valley. — These are traced along the 

 upper course of the valley from near Limpsfield. They seem to 

 show glacial influence, and Mr. Bell has discovered a few implements 

 in them. The Limpsfield deposit is from 10 to 30 feet below the 

 adjacent gravel. Brick-earth, possibly of somewhat later date, also 

 occurs near Dartford. 



vii. Other Gravels of the Darent Valley : The Chevening and 

 Dnnton Green Drifts. — The relations of the gravels grouped under 

 this head are more uncertain than those of the Limpsfield stage. 

 Various features in the gravels point to the temporary return of 

 glacial conditions during the period of formation of these and the 

 brick-earths ; and these are described in detail. 



viii. The Loiv-levd Valley-Gravels. — The correlation of these is 

 also uncertain. West of Dartford is a bed corresponding with that at 

 Erith in which Mr. Spurrell found a palaeolithic floor. It contains 

 land- and freshwater-shells. The surface of the Chalk is here 

 festooned under a covering of the fluviatile drift. The author 

 attributes this festooning to the effects of cold. 



