Origin of the Bale of Jftarshtooob 

 of the (Smnsaiib ills of 



By A. J. JUKES BROWNE, B.A., F.G.S. 



(Published with the permission of the Director-General of the Geological 

 Survey of Great Britain.) 



(Read at Dorchester, Nov. 20th, 1S96, and again on Pilsdon Pen, 

 June 8th, 1897. ) 



JTEHE great sheet of chalk which, with the subjacent 

 Greensand and Gault, stretches through so 

 large a part of Southern England and 

 underlies the whole of the Hampshire Basin, 

 terminates abruptly in West Dorset. There 

 is no doubt that the Upper Cretaceous Rocks 

 once spread continuously over the Jurassic 

 hills east of Bridport and across the Vale of 

 Marshwood, and were united to the corres- 

 ponding beds in East Devon, where the Chalk and Greensand are 

 so conspicuous in the cliffs near Beer Head. 



To some it may seem that this statement is rather too 

 imaginative, since, at the present time, there is a broad intervening 

 tract, from the centre of which all traces of Cretaceous strata have 

 been removed, and around which only a few isolated patches or 

 outliers of Greensand remain as relics of their former extension ; 

 yet to the eye of a geologist these very outliers, of which Pilsdon 



