Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/369

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1869.]
ORMEROD—DARTMOOR GRANITE.
273

they at present exist. The ancient rivers had no doubt run at far higher levels than at present. Even the watersheds afford no gauge of the ancient bounds of the rivers.

Mr. Evans stated his belief that the gravels on the plateau between the Little Ouse and the Wissey belonged to the Glacial series. He could not agree with the author in limiting the occurrence of the implements to the base of the beds, in ignoring the eroding power of rivers, or in regarding the deposits at Lakenheath and Vaudricourt as remote from all possible river-action. He maintained that the whole of the phenomena were in accordance with the excavation of the valley, since the highest beds with implements had been deposited near Brandon, and pointed out that a large part of the great plain of the Fens had probably been formed principally by tidal action, since the deposit of the gravel-beds at Shrub Hill.

Mr. Searles Wood regarded the valleys of the district under consideration as not formed by river-action, but by tidal action during emergence of the land. He regarded the higher gravels mentioned as not of river origin, and dissented from the hypothesis of the rivers of the south of England having formerly run at very high levels.

Mr. Flower, in reply, could not accept the belief that the process of the manufacture of these implements could have been carried on during the very lengthened period supposed by Mr. Evans, as, if so, other traces of the men who formed them would have come to light. He thought the French theory of diluvial action was more in accordance with the phenomena than that of fluviatile transport.


May 12, 1869.

Francis Henry Brown, Esq., of Bishwell, near Swansea; Samuel Jenkins, Esq., 13 Clement's Inn Passage; Lieut. Walter Haweis James, R.E., Brompton Barracks, Chatham; Charles Lambert, Esq., 3 Queen Street Place; Gordon Broome, Esq., Royal School of Mines, and Thomas William Gardner, Assoc. Inst. C.E., 10 St. Augustine's Square, Camden Road, N.W., were elected Fellows of the Society.

The following communications were read:—

1. On some of the Results arising from the Bedding, Joints, and Spheroidal Structure of the Granite on the Eastern Side of Dartmoor, Devonshire[1]. By G. Wareing Ormerod, Esq., M.A., F.G.S.

The following pages will be confined to observations on some of the effects which bedding, perpendicular joints, and spheroidal structure have produced in the physical features of Dartmoor. In the report on the geology of Cornwall, Devon, and West Somerset, Sir Henry de la Beche states (page 157) "that the granite of Dartmoor

  1. The district described in this paper is included in the Map published in the Quarterly Journal of the Geological Society, vol. xxiii. p. 418.