GEOLOGY CROMER FOREST BED Overlying the Chillesford series at Kessingland and exposed also at the foot of the cliffs at Corton is the Cromer Forest Bed — the Cromerian or zone of Elephas meridionalis — a series of freshwater and estuarine de- posits, comprising dark peaty clay with seeds and other plant lemains, greenish stony clay, and gravel some lo or 15 feet thick. The dark peaty clay forms a black bed, perhaps an old lacustrine deposit, which lies in hollows above the rootlet bed, and these strata at Kessingland appear generally to occupy an eroded surface of the Chillesford Clay. The greenish stony clay is penetrated by roots, and has been termed the rootlet bed ; remains of freshwater shells are found in the XJnio bed, a gravelly layer at the base of the black bed, in which occur Unto pictorum and Pisidium astartoides ; while remains of elephant, hyaena, rhinoceros and deer are found at different horizons in the Forest Bed Series. These interesting layers have attracted much attention from John Gunn, J. H. Blake and others, while the organic remains from Corton were specially looked after by J. J. Colman.' The bed with rootlets was first described by S. R. Pattison in 1863.^ It is however a difficult task to clearly make out the sequence along the cliffs from Kessingland to Corton, because not only does the Forest Bed Series rise very little above the sea-level, but a great portion of the cliffs along their base is usually obscured by talus and blown sand. It requires an attentive study on many occasions during successive winter and spring seasons before a clear notion of the relations of the strata can be gained. The story however has been made out, and Mr. Clement Reid remarks that the Pliocene land fauna and flora is mostly of temperate species. There were forests of oak, Scotch pine, beech, birch, elm, hazel, hornbeam and cornel. The lakes were full of yellow water-lily, water-crowfoot and various existing species of pond weeds ; their shores were occupied by thickets of alder and willow, by osmunda, or dense growths of reeds and sedges.' PLEISTOCENE AND RECENT GLACIAL DRIFT It must be borne in mind that the divisions in geological time are simply convenient groupings. The Pliocene and Pleistocene periods merge imperceptibly whether we consider the physical changes or the strata which furnish the records. The Glacial Drifts of earlier Pleistocene age were spread irregularly across the entire country, and to this mantle of clays, sands and gravels
- Blake, 'Geology of the country near Yarmouth and Lowestoft,' Geol. Survey (1890), p. 17 ;
Prestwich, ^art. Journ. Geol. Soc. xxvii. 463 ; E. T. Newton, ' Vertebrata of the Forest Bed Series.' ^ Geologist, vi. 207. ^ Natural Science, vii. 176 ; 'Pliocene Deposits of Britain,' pp. 146, etc. I 17 3
