PROCEEDINGS OF THE COTTESWOLD CLUB 77 



Nearly two square miles of alluvial soil covers the 

 Oxford Clay a little south of the Thames from Blackford 



to Inelesham. ., , 



The Oxford Clay occupies nearly 15 square miles and 

 the Corallian nearly y/.. The small amount of drift or 

 alluvial soil resting upon the Oxford Clay does not exceed 

 2 square miles. 



BASIN OF THE RiVER COLE 



The Cole enters the Thames half-a-mile east of Lechlade 

 Bridge, and a little above or west of St John's Weir 



The Cole is the chief stream in the Swindon Basin, 

 rising both in the Portland Sands of Swindon and the 

 Chalk and Upper Greensand of Chisledon and Liddington 

 flowing for two-and-a-half miles over the Gault and Lower 

 Greensand to Foxbridge. Another set of tributary streams 

 rise in the Upper Greensand between Wanborough, 

 Bishopstone and Ashbury, flowing over the Kimmeridge 

 Clav to where the roadway crosses the Wilts and Berks 

 Canal, there becoming the main stream at Warneford 

 Place a branch of which drains the Sevenhampton Valley 

 in the Oxford Clay and Calcareous Grit and unites at 

 Warneford Place. The Cole then winds its way into, and 

 over the Oxford Clav Vallev to Coleshill, five miles north 

 of which it reaches" the Thames at St John's Bridge and 

 Weir The tributaries of the Ray and Cole rise and 

 nearly meet at Great Copse, each rising on either side 

 of the main road to and from Swindon. 



The Cole like the Ray chiefly drains from the surface 

 of the Oxford and Kimmeridge Clays and Gault, which 

 during heavy falls of rain release from their surfaces large 

 volumes of water. 



The Cole drains an area of about 56 square miles from 

 five divisions of the Jurassic and four of the Cretaceous 

 Rocks, viz. : 



