372 PROCEEDINGS COTTESWOLD CLUB 1912 



A lake of moderate depth could have been held up by 

 ice advancing from the Irish Sea along the area of the Bristol 

 Channel, the barrier being reinforced by glaciers from Central 

 and South Wales' and by Glacial debris carried down by the 

 Severn, Wye, Usk, and Taff. 



There are, however, no traces of moraines in the tideway 

 or on the eastern banks of the Channel, over which any effec- 

 tive barrier of ice or moraine matter must have extended ; 

 yet it is possible that the evidence may have been removed by 

 slight submergences such as may well have occurred in the 

 region in question with its characteristic rapid tides. 



The shoaling of the water on the north of the Flat Holmes 

 has been considered to point to the existence of a moraine ; 

 and the great variety of the rocks found there and in other 

 parts of the Channel is cited in support of this contention ; 

 but the question of erratics is complicated by the unloading 

 of ballast from vessels hailing from Baltic and British Ports. ^ 



On the supposition that the Sands were deposited in an 

 estuary or lake in the Severn Plain, limited to the depth of 

 which there is any evidence, it would be difficult to account 

 for their occurrence at the elevations they attain at Charlton 

 Kings and in the Dowdeswell Valley. They may, however, 

 have been tarried thither by winds' in dry seasons, the thin 

 layers of sand being covered with Jurassic debris on the 

 recommencement of the flow of water down the valley of the 

 Chelt, thus causing a rude stratification that indicates seasonal 

 or other periodical changes with intervals when the fiood wash 

 of gravel from the hills was suspended. 



The Cheltenham Sands do not appear to have been 

 derived from Jurassic rocks of the Cotteswolds or from the 

 arenaceous soils of the plateaux, since they are of much 

 coarser grain than either. It is possible that they may have 

 been carried by torrents from melting ice in the upper part of 

 the Avon Valley, where sands of similar colour and texture 

 occur, the coarser materials being carried by the main stream 

 down the centre of the Severn Plain, the finer burden settling 



1 C/. Geikie, "The Great Ice Age," p. 363. 



2 Mr. F. G. CuUis, of Bamwood Court, informs rae that some large water-worn granite boulders 

 now in his grounds came from the Baltic as part of the ballast of a timber ship. 



3 As in the case of the Blown Sands that extend to the Chalk escarpment of Yorkshire and 

 Lincolnshire. 



