The Essex Naturalist
7
The advance of the Anglian glacier blocked this course and diverted the
Thames into its modern route to the Southend area, though initially it flowed
on northwards from Southend to rejoin its old course in the Clacton area (Fig.
2b). An early history of the Thames in eastern Essex is given by Gregory (1922).
Recent overviews are given by Gibbard (1985, 1994, 1995) Whiteman and Rose
(1992), Bridgland (1994), Bridgland et al. (1995) and Sumbler et al. (1996).
This review will concentrate on the detail and context of the history of the
Lower Thames, the portion of the river downstream of London.
To understand the geological history it is necessary to understand (a) the
geological processes and (b) the Stratigraphical procedures involved. There are
still debates about the nature of these processes and procedures.