THE CHANGING COASTLINE OF ESSEX
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as a long, narrow ridge, together with any secondary material
like shellcasts brought to the area by normal shoreline
processes. The possible stages in the evolution of the
feature are given in Fig. 6. In this explanation it will be
noted that the marsh on the landward side of the ridge is
regarded as being older than the ridge, whereas in the
offshore bar hypothesis the marsh is formed later. Although.
Fig. 6. Stages in the evolution of the Dengie Peninsula shoreline.
as far as the author is aware, the marsh bar has not pre-
viously been described in the British Isles, similar forms
have been recognised by D. W. Johnson on the New Jersey
coast of America. (Johnson, 1919.) He distinguished them
from true offshore bars by their small size and irregularity
and in that they are usually found on unexposed coasts