44
THE ESSEX NATURALIST.
south the dominant direction is west to east. The north-western
"rakehead" (the Chelmer, Brain and Pant) appears to be
flowing towards the Hanningfield syncline lying along the
south-western termination of the Tiptree feature—the syncline
passing north-eastwards beneath the Blackwater estuary. The
southern streams are directed to a continuation of the same
depression which forks eastward beneath the Crouch valley
(fig. 1). It would appear that this buried "Y"-shaped de-
Fig. 2. The Existing Rivers of Eastern Essex.
pression near the upper Crouch was once the district containing
the longitudinal consequent stream to which these northern
transverse consequent streams flowed. These observations seem
to give further support to the following theories of the Proto-
Thames' channels, in which we shall be able to trace the shift
of these channels across the arms of the "Y" and the forma-
tion of the three broad south-eastern surface valleys. These
successive river channels have been traced with some accuracy
on the evidence afforded by the water-borne sands and gravels
to which reference has already been made.