514 boeings at culford, winkfield, ware, etc. [aug. 1 894. 



Discussion. 



The President pointed out the importance of the work in which 

 Mr. Whitaker, one of the Authors, had been engaged for so many 

 years in recording all borings and well-sinkings, and (as in the 

 present cases, described by the Authors) adding most valuable 

 information as to the contours of the ancient underground ridge of 

 Palaeozoic rocks, on which the Secondary rocks rested unconformably 

 over so large an area of the Eastern and South-eastern Counties of 

 England. 



Prof. Boyd Dawktns agreed with Mr. Whitaker in his general 

 conclusions as to the Palaeozoic floor rising to the north, and pointed 

 out that the sequence of the Palaeozoic rocks in the London area 

 and the district to the north was exactly that which may be studied 

 at the surface in South Wales, Gloucestershire, and Somersetshire. 

 He further called attention to the fact that the non-discovery of 

 coal-bearing rocks in this area was not to be taken as proving the 

 non-existence of coalfields in the London Basin. It merely implies 

 the existence of a pre-Carboniferous region between Ware and 

 Streatham, and between Eichmond and Erith, analogous to that 

 which separates the coalfield of South Wales from that of the Eorest 

 of Dean, and from that of Gloucester and North Somerset. The 

 shale at Culford seemed to him probably of Silurian age, and quite 

 unlike any Yoredale or other shales belonging to the Carboniferous 

 period. The shale at the bottom of the Harwich boring is of 

 Yoredale age, and contains Poseidonia. 



Prof. Jttdd asked Mr. Whitaker whether he had considered the 

 evidence supplied by the Northampton borings as to rocks of the 

 Palaeozoic plateau. We have evidence there of red rocks with Car- 

 boniferous plants and other fossils, and he was not sure that the 

 beds occurring at the bottom of the Eichmond boring might not be 

 the same abnormal Carboniferous rocks. 



Mr. Toplet also spoke, and Mr. Whitaker briefly replied. 



