THE 
GEOLOGICAL MAGAZINE. 
NEW SE RIESs DECADE Vi VOR Vil: 
No. II.— FEBRUARY, 1910. 
@RPtG aN VATE), “ASkvl teGria aS: 
od 
J.—Tue Scurrrurrnnes or tHe CHatk Downs or Kent, Surrey, 
anv Sussex.' By Groren Crinen, F.G.8., F.S.A. Scot. 
(PLATE VI.) 
fY\HE aim of this paper is to offer an explanation of the phenomena 
intimately related to the sculpturings of the Chalk Downs ‘in the 
district under review, namely :— 
(1) The Dry Chalk Valleys. . 
(2) The River System of the Wealden area, as far as it relates to 
the Chalk Downs. 
(3) Incidentally, the Denudation of the Wealden area. 
The various sculpturings of the Chalk Downs fall naturally into 
two main groups, viz. :— 
(1) Dry Valleys, comprisinge— 
(2) Simple coombes, or short valleys, without tributary valleys, and 
(4) Complicated, sinuous valleys, usually extending for some miles, and 
with numerous tributary valleys. 
(2) Wet Valleys, cut through the North and South Downs, in which flow rivers 
which drain the Wealden area. 
The chief characteristics of the Dry Valleys (1) are steep, sloping 
sides, rounded outlines, absence of terraces, general absence of deposits 
of flints, etc., and proportionately large area of valley as compared 
with unsculptured areas. 
The simple coombes or short valleys (@) are found usually on the 
Chalk escarpment opposite the Weald, and are remarkable for their 
steepness, both of sides and the general fall of the level of their 
deepest parts. (See Pl. VI, Fig. 1.) 
The complicated, sinuous valleys (6) are found usually on the 
northern slope of the North Downs and the southern slope of the 
South Downs. The number of tributaries and the breadth of 
the valleys are two remarkable features to which no one yet seems 
to have drawn particular attention. They are points which certainly 
do not appear to have been sufficiently explained by the theories 
hitherto advanced by geologists. If at first they seem to present 
‘difficulties, these very difficulties are of the greatest value as indicating 
1 This paper is substantially the same as that communicated to the Geological 
‘Society of London, April 7, 1909, certain revisions having been made subsequently. 
A short abstract only was printed in the Q.J.G.S., vol. Ixv, pp. 208-9. 
DECADE V.—VOL. VII.—NO. II, 4 
