Vol. 54.] IN SOUTH WALES, DEVON, AND COENWALL. 277 



during and after Neolithic times. While not disputing the identifi- 

 cation, he wished to know on what evidence some of the deposits had 

 been classed as Glacial, and what was the distinction between them 

 and the ' stony clay ' referred to in other valleys. In the estuary of 

 the Dee there occurred a layer of great boulders at the base of the 

 alluvial deposits ; these had no doubt been washed out of a Boulder 

 Clay, but did not themselves constitute a Glacial deposit. 



Mr. C. E. DE Eance spoke of the great value of such a record of 

 observed facts as that given by the Author in his paper. It 

 mattered little whether true Glacial deposits had been discovered or 

 not in these submerged valleys in South Wales and the South-west 

 of England, as there could be no doubt that these valleys were 

 excavated by rain and rivers before the Glacial episode. Similar 

 valleys in North Wales, Cheshire, and Lancashire occur at depths 

 of nearly 200 feet below the mean tide-level, and are filled up 

 to the existing height with undoubted Glacial deposits, through 

 which posfc-Glacial valleys have been excavated 1| mile wide ^nd 

 180 feet deep, at the bottom of which occurs the modern alluvium, 

 consisting of silt, peat, and heavy gravel. The peat is connected 

 with the thick peat of West Lancashire and Cheshire, which 

 descends to a level of at least 70 feet below mean tide. On its surface 

 is Scrobicularia-clsiy, in which Roman coins occur just below high- 

 water mark at Fleetwood : so that the post-Glacial subsidence is 

 older than the Roman epoch. He connected the massive gravel 

 with the stream-tin deposits of the South-west, which he considers 

 to be of post-Glacial age. The facts given by the Author, correlated 

 with the observations made farther west, point to a common 

 cause. 



Dr. Hicks agreed with the Author that the valleys in South Wales 

 referred to were of pre-Glacial age and had originally been filled with 

 Glacial deposits. These, and others which the speaker had examined 

 on the Welsh coast, still contained Glacial deposits in the parts 

 beyond the reach of tidal erosion. The varying depths at which the 

 rock-bottom had been reached were partly due to more rapid marine 

 encroachment in some areas than others. 



Prof. Seelet regarded these valleys as evidences of upheaval of 

 the country, and of its excavation by subaerial denuding agents 

 during the Miocene or Pliocene period. Deep and narrow valleys in 

 Cambridgeshire, especially the west, were filled with Boulder Clay, 

 and they had been shown by well-sinkings to descend much below 

 the present sea-level ; so that the elevation, which affected a wide 

 area of country, was pre-Glacial and may have been a condition 

 leading up to glaciation. The inland valleys often retained the 

 filling of Boulder Clay, but those which descended to the sea had 

 been mo^-e or less scoured out, though filled with a subsequent 

 down wash of mud. 



Mr. A. E. Saltee understood from the paper that the Author corre- 

 lated the deposits found in these submerged valleys with the Glacial 

 deposits of the Thames and Erome areas on the one hand, and with 

 the stream-tin deposits of Cornwall on the other. In the former 



