76 PROCEEDINGS OF THE COTTESWOLD CLUB 



- 7^ sq. mis. 



Jurassic 



Cretaceous 



1% 



'The Oxford Clay - 



,, Lower Calc. Grit - ^ 



„ Coral Rag - - ^y^ 



,, Kimmeridge Clay - 15 



,, Portland Sands and 



L Purbeck 



,, Lower Greensand 



„ Gault 



„ Upper Greensand 



„ Chalk 



As before stated the waters collected from the southern 

 Cretaceous escarpment drain or flow north, w^hilst the 

 rocks dip south-east, and the probable underground line 

 of parting between the Basin of the Swill Brook and the 

 Dance and Ray is nearly coincident with the western and 

 local watershed of the Dance Brook. 



Area between the Rivers Ray and Cole, (the 

 HiGHWORTH Streams) 



These streams drain directly into the Thames by the 

 Shire Ditch, the Byde Mill Brook and small streams. 

 The drainage area between the Ray and the Cole occupies 

 eighteen-and a half square miles, fifteen of which is upon 

 the Oxford Clay: the remaining or Corallian Beds (Calcare- 

 ous Grit and Coral Rag) supply water from the united 

 drainage of 3^ square miles. 



This district supplies the Thames at Blackford, through 

 the western branch, or Shire Ditch tributary, and the 

 eastern or Byde Mill Brook near Inglesham, a north- 

 west and south-east Fault ranges between Hannington 

 and Highworth, nearly reaching to Sevenhampton. 



