362 PLEISTOCENE GEOLOGY OF THE THAMES VALLEY.
of this disturbance is coincident with that of the east and west
valley to the south of Sockett's Heath mentioned above. There
can hardly be any question as to the cause of the disturbance
affecting this gravel. The synclinal folding of the lower part,
the irregular character of the detritus which fills up the hollow
thus formed, and the vertical position of the constituent stones
of the latter seem to admit of but one explanation. All these
Fig. 2. Section in Sockett's Heath Gravel Pit. 1, Irregular Gravel ;
2, Unstratified Sand ; 3, Unstratified Loan ; 4, Regularly Stratified
Sand and Gravel, false bedding in places ; 5, Thanet Sand (full thick-
ness not shown.) X—X, The floor of pit, below which the drawing is
diagramatic.
characters were brought about as the result of the underground
dissolution of the Chalk by water charged with carbonic oxide
and organic acids acting along a more or less definite line of
weakness. This section simply supplies proof of the existence
of a process operating in the district whereby the surface of the
Chalk is dissolved away, the result of which is that furrows and
grooves are eroded in it into which the superjacent strata gradu-