I48 HAZZLEDINE WARREN : STUDY OF PRE-HISTORY IN ESSEX. 
Rayleigh Hills (A. E. Salter, E.N., xiv., 1907, p. 267). 
Eolith from the high level gravels. 8 
Obscured Interment (E.N., xv., 1908, p. 146). Dr. A. E. 
Salter found a portion of a skeleton in a pit on One Tree 
Hill (Laindon Hills). It was found 6 feet from the surface 
in Bagshot Sand and showed no evidence of disturbance 
or of the existence of a grave. The lesson from this is 
sufficiently obvious, and needs no comment. 9 
III.— Relation of Paleolithic and Glacial Deposits. 
In considering this problem, we should always hold in mind 
the influence of the pre-Glacial undulations of the land on which 
the drift lies, and also the anomalies of glacial erosion. We 
must be prepared for striking irregularities, particularly in the 
case of those narrow, deep, drift-filled channels which never 
possessed an outlet to the sea corresponding with their own 
depth and are essentially of the nature of lake-basins. 
Cam Valley (W. Whitaker, E.N., iii., 1889, pp. 140-2 ; iv., 
1890, p. 117 ; ix., 1895, p. 169). Such a drift-filled channel 
has been proved by borings at Newport, Wen den, and 
Littlebury. At the former place, 340 feet of drift has 
been proved (140 feet below O.D.), without touching the 
bottom. As the country rock is chalk, there can be no 
doubt of the accuracy of this conclusion. 10 
Kelvedon (G. F. Beaumont, E.N., i., 1887, p. 189). Another 
similar channel, reaching a depth of 194 feet (106 feet 
below O.D.), may exist here. Contributary evidence [12] 
supports the accuracy of this conclusion, although in itself 
it rests largely upon the interpretation of the well-sinkers’ 
descriptions. The record speaks of 194 feet of “ blue 
clay, stone, and chalk ” over-lying “ blue Clay.” It is 
assumed that the former is all true Boulder Clay, although 
the London Clay contains much septarian material, which 
might be described as “ stone and chalk ” by a non¬ 
geologist. 11 
Blackwater Valley (W. H. Dalton, T. & P., ii., 1881, p. 15 ; 
E.N., iv., 1890, p. 104). In the higher reaches, the Boulder 
Clay forms only the top of the plateau between the Guith 
and the Blackwater. Between Feering and Witham, it 
has descended into the valley and has cut through the 
Glacial gravel deeply into the London Clay, but does not 
rise far on to Tiptree ridge. The Pleistocene Valley gravel, 
about Kelvedon and Witham, overlies this Boulder Clay. 12 
Kelvedon-Tollesbury, visit to new railway ( E.N ., xiii., 
