Geology if Norfolk page 2

At a later period, when the Norfolk valleys were becoming free from ice, but while it continued to exist elsewhere, floods still prevailed, but they were confined to the lower ground. Gravels of a finer character than those of the plateaux accumulated then within the valleys, but in positions which show that the floods to which they were due reached a much higher level than do those of the present day. Near the Thorpe railway station at Norwich, for instance, are some gravels which wrap the sides of the valley to a height of perhaps thirty feet above the river, although they pass also under its bed.

Whether man inhabited Norfolk before the Glacial period is still a quastio vexata, but uncivilized races, using unpolished flint weapons, certainly occupied the county during the deposition of the valley gravels, a palaeolithic implement having been found in them by the writer at Cringleford. The famous deposit at Hoxne near Diss, where more than 100 years ago these relics of primaeval man were first discovered, lies just beyond the confines of the county.

In the valley of the Nar, in West Norfolk, are some brickearths, the sediment of an estuary formerly opening westward into the Wash, from which bones and teeth of the Mammoth, Elephas primigenius, and of the woolly Rhinoceros, R. Tichorhinus, with specimens of an arctic shell, Tellina lata, have been obtained. These deposits, though probably more recent than some of the valley gravels, belong also to the post-glacial series, to a period when the climate of Great Britain was colder than it is at present.

During the post-glacial epoch, the comparative level of land and water in Norfolk varied from time to time. At one period the country stood higher than it now does, and England was joined to the continent. Hence the close resemblance between the fauna and flora of the two areas. At another time it probably stood somewhat lower.

Eventually, however, the valleys of Norfolk became choked by the accumulation of fluviatile and estuarine mud, and by the growth of peat. The low marshy ground bordering rivers like the Yare or the Wensum, now embanked and drained, were at no very distant period impassable and waterlogged swamps, along the margin of which browsed herds of extinct forms of the wild oxen, Bos primigenius, and Bos longifrons, whose fossil remains are occasionally found there, and may be seen in the Museum at Norwich. Peaty beds of similar character to these are still accumulating in the Broad district of East Norfolk, by the annual growth and decay of marsh plants.

It is not possible, within the limit of a rapid sketch, to do justice to such a subject as that of the geological history of Norfolk. It is to be feared that there are in the county at present few serious workers in this important and fascinating field of enquiry, but much remains to be accomplished, and results of great scientific value and interest still await the diligent student.