Page:VCH Sussex 1.djvu/54

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A HISTORY OF SUSSEX reef-building corals are absent ; but this may be due more to the muddi- ness of the water than to the absence of sufficient warmth. The large foraminifera also, though of extinct species, suggest tropical seas, and it is interesting to find in Egypt whole hills made up of nummulite lime- stone, belonging to a period not far removed from our Bracklesham. The palms also point to a high temperature, though the cones of pine occasionally found associated suggest a climate somewhat less warm. Few pines are now found in the tropics ; but on the other hand in the Bracklesham Beds pine-cones are rare and may have drifted enormous distances, while nuts of nipa occur in profusion in certain beds, as do the tropical shells. It has been asked. In what direction lay the continent or large island from which flowed the river that brought this mass of sediment and all this driftwood ? The question is not easy to answer, for though slight indications point to land to the west or perhaps south-west, yet Bracklesham Beds of similar character, though much thinner, and containing the same nipa {Nipa burtini) are found in Belgium also. Perhaps the most probable analogy is with a tropical archipelago, such as the Malayan, with its dotted large and small islands. The few land animals found in the Bracklesham Beds are more suggestive of scattered islands than of a continent anywhere very near to Sussex. From the Bracklesham period onward through several other periods the records have been destroyed in Sussex, and all that can be done is to outline roughly the probable course of events up to the Glacial epoch. This we are enabled to do through records preserved in adjoining counties, though for some stages the history is still so obscure that reconstruction is impossible. The marine Barton Beds, which complete the Eocene series, are well developed in Hampshire and the Isle of Wight, and they doubtless once extended over Sussex also. Whether this was the case with the fluvio-marine Oligocene strata which succeed is more doubtful ; for the deposits, though 600 feet thick no further off than the Isle of Wight, consist so largely of lacustrine sediments that land cannot have been far distant. Slight indications however suggest that the land then lay to the south and west, and that the deposits became more marine towards Sussex, and are therefore more likely to have been continuous over that county. The succeeding Miocene period has left no records either in Sussex or anywhere else in Britain ; but it is almost certainly to this period that we may refer the great earth movements which caused the folding and bending of the strata to which reference has already been made. The mode by which we arrive at this date is as follows : The Eocene and Oligocene strata of the Isle of Wight form a continuous series without break up to the Middle Oligocene ; but the whole of these rocks have been tilted and folded as one mass, so that in places the bedding is now vertical : therefore the great period of disturbance was later than Middle Oligocene. To ascertain the date when the great movements had ceased we reason thus : The earliest Pliocene Beds of Kent rest on an eroded 16