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in of the great Glacial subsidence. They consider them to be unconformable to the Chillesford Beds, because in certain places along the Bure Valley and near Halesworth, the Chillesford Beds have been denuded prior to their accumulation. They are characterized by the first appearance in England of Tellina Balthica (solidula). The other fossils include Tellina obliqua, Cyprina Islandica, Leda obiongoides, Cardium edule, Litorina litorea, &c.
These beds range from the Bure Valley past Norwich to the neighbourhood of Southwold, and expand northwards into the Weybourn sand. In the Norfolk Cliffs they form a very variable series.
East of Cromer the sand becomes charged with lignite, and often laminated with bands of lignitiferous clay, in which condition it constitutes the Laminated beds' of Mr. John Gunn. It passes up in places by interbedding into the Cromer Till.
In some localities near Norwich there is no definite line of separation between the Bure Valley Beds and the Chillesford Beds, and Fluvio-marine Crag beneath ; and moreover they seem all of them to be so closely connected in their derivation and method of accumulation, that I prefer classing them together as one group-the Norwich Crag series,
REST BED SERIES.
One of the most remarkable deposits with which we are acquainted is the so-called Forest Bed of Cromer on the
Mr. Gunn considers these Laminated beds to represent the Chillesford Clay; he, however, uses the term Laminated series as a comprehensive term for all the strata from the Fluvio-marine Crag to the base of the Glacial series, and in the same sense as the term Norwich Crag Series is here used.
Norfolk Coast. This bed, so noted for the Mammalian remains which it has yielded, maintains a remarkable persistence wherever it has been observed, at about the same level, along the shore or fore-shore between Runton in Norfolk and Kessingland in Suffolk.
The Forest Bed occurs at the base of the Glacial series, and beneath the pebbly sands and the laminated beds (=Bure Valley Beds). But its precise relations to the lower portion of the Norwich Crag Series have not been determined. Its junction with the Chalk has never been observed, and therefore the total thickness of the series is unknown.
Its persistence thus along the coast is all the more remarkable if, as Lyell considered, there must have been a subsidence of the forest to the amount of 400 or 500 feet, and a re-elevation of the same to an equal extent, in order to allow the ancient surface of the Chalk with its covering of soil, on which the forest grew, to be first covered with several hundred feet of drift.
As the Forest Bed is intimately associated with several other beds of local interest, the term Forest Bed Series seems most applicable to these deposits.
To the indefatigable researches of Mr. John Gunn we chiefly owe our knowledge of the physical geography and the very interesting fauna and flora of the period when these beds were deposited. Some of his remarks I now quote.
“The soil of the Forest Bed appears to consist of an argillaceous sand and gravel (pan), or a compound of both, and to have been deposited in an estuary. Bones of Elephas meridionalis, together with a great variety of deer and other mammals, sharply fractured, but not rolled, are found in it, especially in the gravel, which is called the “ Elephantbed on that account. These are associated with the bones of whales and fragments of wood, indicating that the Estuary
was open to the sea, most probably northwards, for the admission of the whales; while it appears to have been closed at the Straits of Dover and Calais, to afford a passage for the mammals into this country. This deposit of the soil may be regarded as the first phase of the Forest Bed; and here, we may observe, a long interval may have intervened between this and the second phase, which dates from the raising of the soil to the surface of the waters and the growth of the forest upon it. In this the remains of the E. antiquus are most abundant; other varieties of the Elephant are found here, together with Rhinoceros etruscus and Trogontherium Cuvieri. This may be regarded as the true Forest Bed; the stools of the trees belonging to it are visible along the coast at various places from Kessingland to Cromer.' (Gunn.)
A black freshwater peaty clay, with Unio, &c., and a rootlet-bed' occur above the Forest Bed at Runton, Kessingland, &c.
Blue clay and gravel indurated into “pan’ may be traced at intervals along the coast near Overstrand Gap, Mundesley, Trimmingham, and Cromer. At Bacton the clay is of a greenish colour.
Those who wish to examine the Forest Bed of Cromer may be disappointed in not being able to determine its exact relations to the Glacial beds in the cliff-sections, for seldom save at low tide can the Forest bed be seen at all, and it is only at a few places that it has been seen in situ beneath the Glacial beds, owing to the recent deposits of sand and shingle that are banked up against the cliffs.
Through the Forest Bed are scattered cones of the Scotch and spruce firs with the seeds of recent plants, and the bones of at least twenty species of terrestrial mammalia. These mammalian remains occur chiefly in the pan, and include
Elephas meridionalis, E. antiquus, Hippopotamus major, Rhinoceros etruscus, Bison priscus, Cervus (several species), Trogontherium Cuvieri (a gigantic Beaver), &c.
We are greatly indebted to Mr. John Gunn for the large collection of these remains placed in the Norwich Museum, and to the late Rev. S. W. King for a collection now in the Museum at Jermyn Street.'
Messrs. Wood and Harmer consider that with the exception of certain cetacean vertebræ found in the Chillesford Clay at Chillesford, it is open to question whether any of the Mammalian remains obtained from the Fluvio-marine Crag, or from the Chillesford beds, belonged to individuals which lived during the accumulation of these deposits. The Mastodon teeth found in the Red and Fluvio-marine Crags, and in the Chillesford Beds, have, they think, been derived from destroyed freshwater deposits intermediate between the Coralline Crag and the Red Crag. From the fact that no trace of the Mastodon has yet been found among the abundant elephantine remains from the Forest Bed, they consider it doubtful whether that animal lived during the age of the Chillesford Crag ; since the Forest Bed, if it be not actually coeval with this deposit containing Mastodon remains, is evidently separated from the latest of them by an interval of time too slight (and accompanied apparently by no change of climate) satisfactorily to account for the disappearance of this great proboscidean genus.
Thus, while there is no evidence to show that the Forest Bed Series, with its estuarine soil, its land surface, and subse
1 A great number of Mammalian remains have been dredged off the cuast ; according to Mr. S. Woodward, the Oyster Ridge off Happisburgh and the Knole Sand off Yarmouth have contributed most largely. He mentioned that at one time the Rer. James Layton of Catfield had as many as 600 grinders of the Elephant! Most of these remains, however, belong to a Post-Glacial deposit, and not to the Forest Bed.
quent freshwater deposits, may not have been accumulated (at any rate in part) contemporaneously with the deposition of the Fluvio-marine Crag, its exact relation to the Chillesford Beds is a matter of dispute, but there is no question whatever that subsequent depression allowed the Bure Valley Beds to extend over a larger area than that occupied by the Fluvio-marine Crag and Chillesford Beds, and to rest in places directly upon the Forest Bed Series.