A NEOLITHIC FLOOR.
261
There is, nevertheless, evidence that land which was occupied
at some time during the Roman period is now buried in river mud,
or covered by the sea, as is shown by Mr. Dalton in his recent
paper, together with notes by Dr. Laver.8 Portions of towns
like Othona are washed away ; the extensive site of the Up-
church potteries is now covered by the sea at every high-tide ;
the foundations of Roman buildings at Southwark lie many feet
under ground, covered with a deposit of tidal mud. Roman
sepulchral remains are found in several of the Kentish marshes,
which are now regularly inundated, and also in the gravel of
Moorfields, buried under many feet of black peaty mud.
On the other hand the Roman port, Rutupiae (Richborough),
is now far inland, while at other points there are no indications
that any appreciable change of level has taken place.
Tidal action and slight local earth movements may be held
to explain these seeming inconsistencies, but I venture to think
the evidence points also to some change of far-reaching extent,
during Roman times, but not one wholly of subsidence. It
seems probable that one of those breaks in the general lowering
movement occurred at this period, and that about the time of
the coming of the Romans a slight elevation of the east-coast
took place. This, after an interval, was followed by subsidence,
which has continued, though apparently at a slower rate of
progression, to the present time. (See Fig. 9.)
Mr. Hazzledine Warren" tells me that he has noticed indi-
cations, on the Lincolnshire coast, of a depression of the land,
which "suggest that considerable inroads of the sea upon the
marsh lands took place about the middle of the Roman occu-
pation. These inroads may well have been caused by some
slight subsidence."
There are many evidences of a like phenomenon on the Essex
Coast and the Thames district. Unless this subsidence were pre-
ceded by a movement in the opposite direction, we have to
suppose so great a fall in the level as to be in conflict with other
evidence, while such an alteration, as I have suggested, would not
necessarily imply that the level at the present time, is much
changed since the latter part of the Roman period. The marked
changes having taken place during the earlier portion of the
8. Essex Naturalist. Vol. xvi., pp. 96-101. "Subsidence of Eastern England and
adjacent areas.''
9 See Essex Naturalist. Vol. xvi., 100.