488 



MR. H. ODLrNG ON THE 



[Oct. 1 913, 



III. Details of Sections. 



(a) 1 Ardley Section (fig. 2), 



A very complete section was 

 afforded by the cutting on the 

 Great "Western Railway (new 

 Birmingham main line) between 

 Bucknall Bridge and Fritwell 

 Tunnel. In a distance of about 

 3| miles all the beds were exposed, 

 from the base of the Cornbrash to 

 the top of the Upper Lias. 



The beds may be described as 

 undulating, with a general south- 

 easterly dip ; about two-thirds of 

 the way between the Fewcot & 

 Somerton Road and the Fewcot & 

 Middleton Road, a reversed fault 

 with a north-westerly downthrow 

 brings the uppermost beds of the 

 Forest Marble against the basal 

 beds of the Great Oolite. The 

 cutting, therefore, virtually affords 

 two sections. 



South-east of the fault, all the 

 beds are exposed, from the base 

 of the Forest Marble to near the 

 base of the Chipping-^Norton lime- 

 stone Series ; while, north-west of 

 the fault, the beds from the base of 

 the Cornbrash to the top of the 

 Upper Lias are exposed. The 

 complete section thus afforded is 

 as follows : — 



SpUBS 



uoidiiiBijjJOfj 



Cornbrash (as a subsoil in 

 the fields near the fault). 



Thickness in feet 

 Forest Marble. 



Blue clay 2 



False-bedded limestones 5 



Blue clay 1 



Flaggy limestones 



Dark-blue and green 



clay 8 



ichcs. 



Letters prefixed to headings of sections refer to the map (fig. 1) p. 486. 



