yS PROCEEDINGS OF THE COTTESWOLD CLUB 



Jurassic Rocks 

 37 sq. miles 



Cretaceous 

 185 



fThe Oxford Clay - 13 sq. mis. 



„ Lower Calc. Grit 2^ „ 



„ Coral Rag - - 8 „ 



j „ Upper Calc. Grit 2^ „ 



L „ Kimmeridge Clay II^ „ 



^ „ Lower Greensand i^ „ 



„ Gault - - 8^ „ 



„ Upper Greensand I 



„ Chalk - - 7^ „ 



55K » 



These four Rivers, the Shire Stream, the Byde Mill 

 Brook, the Ray, and the Cole, with their numerous tribu- 

 taries, collectively drain 123^ square miles, and this 

 chiefly from the Oxford and Kimmeridge Clays. 



The direction of the flow of the streams is contrary to 

 the dip of the strata, which may not be conducive to 

 perennial supply, yet during heavy rain-fall they largely 

 contribute to the flood waters oi the Upjjcr Thames Valley 

 above Lechlade. 



Physical Conditions and Geological Deductions 



The clays of the Lower and Upper Lias cease to appear 

 below a line drawn from Rendcomb on the Coin to 

 Hampnet near Northleach, and on to Sherborne, Little 

 Barrington and Burford on the Windrush ; thence to the 

 Valley of the Evenlode near Charlbury, turning north 

 between Enstone and Kiddington to Nethercot on the 

 Cherwell, and then to Fawler : all below this line to the 

 Thames is occupied by the Great Oolite and Cornbrash to 

 the outcrop of the Oxford Clay. The Evenlode joins the 

 Thames one mile south-west of Cassington. 



This defined line or range of the Lias below the over- 

 lying Oolitic Rocks to an unknown depth and spread to 



