Page:VCH Norfolk 1.djvu/45

 GEOLOGY that there were giants in former days. The records of William Arderon (1746), of Richard Cowling Taylor (1822), later on those of Lyell, Prestwich, John Gunn, and more recently of Mr. Clement Reid, have brought vividly before us the character and physical conditions under which this variable series was accumulated. Although stumps of trees, apparently rooted on the spot, have been noticed again and again, yet in every case where attention has been paid to the particular nature of the stumps, it has been found that they have been drifted, not necessarily very far, but no single example in the main portion of the Forest Bed has been proved to have grown on the spot. The Forest Bed itself is of an estuarine character, the deposits being connected with the former exten- sion of the Rhine. Beneath it and above the Weybourne Crag is a Lower Freshwater Bed, which however is known chiefly from derived Pholas- bored cakes of peat and clay-ironstone found in the Estuarine Forest Bed. The Forest Bed consists of ferruginous quartzite gravel, sometimes cemented into an iron-pan, with bands of laminated clay, numerous masses and fragments of wood, mammalian bones and estuarine mollusca. It is but I o or 15 feet thick. Above the Forest Bed is a second or upper Freshwater Bed, marked at its base by a soil — the weathered upper part of the Estuarine Forest Bed — and this being penetrated by small roots is known as the Rootlet Bed. It contains the only vegetable growth in situ that has been noticed. Above it, and occupying hollows here and there, are lacustrine peaty beds, which have been observed at several localities between Sheringham and Mundesley. The well-known ' black bed ' at Runton has yielded specimens of the giant beaver, Trogontherium, and other remains, and in the equivalent Unio-bed at Sidestrand there have been found Vnio tumidus, Hydrobia marginata and other freshwater shells. The occurrence in the Estuarine Forest Bed of specimens of amber and jet, derived from Eocene or Oligocene strata, has before been mentioned. Specimens of them collected on the beach are sometimes manufactured into ornaments by local lapidaries. One of the largest specimens of amber which was dredged off Yarmouth weighs thirty- eight ounces. Mr. Reid has observed that the amber is cast on shore usually after easterly gales ; and he believes that both amber and jet may be derived from a bed on the same horizon as the well-known deposit on the Prussian coast, because the easterly dip of the Norfolk strata might bring in Upper Eocene and Oligocene beds a short distance east of Yar- mouth. Remains of insects and arachnids are found in the amber, and these include an Aphis^ several flies and one spider,^ Evidence of the former extent of the Forest Bed has been observed in the Happisburgh oyster-bed, three miles from the coast, where bones and teeth of elephant were formerly dredged (see p. 24). Among the animal remains from the Forest Bed Series are the sabre-toothed tiger or Machserodus (found also in Kent's Cavern, 247 ; and H. Conwentz, 'On English Amber,' etc., Nat. Science, vol. ix., Aug. 1896, p. 99. 15
 * C. Reid, ' On Norfolk Amber,' Tram. Norfolk Nat. Soc, vol. iii. p. 6oi ; vol. iv. p.