76 F. Barlce, Whcelton Hind, and A. Scott — 



safely infer that some of their lateral branches have already been 

 obliterated. But the normal angle of the head of a chine is less than 

 that of the cliff, and therefore there will come a time when all that 

 is left of the former is an indentation of the line of the cliff, somewhat 

 less steep than the latter ; and if, as happens in more than one 

 instance, the chine ran parallel Avith the cliff, this diminished steep- 

 ness might extend for a considerable distance. This I believe tO' 

 be the true explanation of some at least of the observations on 

 which Dr. Ord and others have relied, but it is not improbable that 

 immediately to the east of the pier another cause may also have 

 been at work. 



The ordinary gradient of the beach is greater than that of such 

 a valley as the Bourne, and even at low water it is rare for more than. 

 100 yards of shore to be ex|)osed. But it is evident from Lyell's 

 account of the submerged forest that in 1830 a very different gradient 

 obtained opposite the Bourne, for he describes it as situated 200 yards 

 from the mouth of that valley and as lying between the beach and 

 a bar of sand about 200 yards off. Such a diminished gradient is 

 easily accounted for as the result of the resistance of the peat in 

 which the forest grev/ to the action of the waves and tides ; but 

 the effect of it would probably be to form a sort of groin, which 

 might (since the beach materials normally travel from west to east) 

 afford a good deal of protection to the cliffs on the Boscombe side 

 of the Bourne, and give them time to assume a very moderate slope 

 compared with other parts of the coast. For many years, however, 

 the submerged forest has been seldom visible,^ and there has been 

 no such decreased gradient opposite the Bourne. This has once 

 more exposed the cliffs to the full force of marine erosion, and 

 in this way we may perhaps account not only for the changes in 

 gradient, but also for the alleged special activity of this erosion 

 between Bournemouth and Boscombe." 



Quartzose Conglomerate at Caldon Low, Staffordshire. 



By F. Barke, F.G.S., Wheelton Hind, M.D., B.S., F.R.C.S., 

 and A. Scott, M.A., D.Sc. 



TN the Geological Magazine for February, 1919, J. W. Jackson' 

 -*- and W. E. Alkins ^ described the occurrence of a quartzose 

 conglomerate at Caldon Low, Staffordshire. In August one of us 

 (F. B.) ^ |)ointed out some previous references to this outcrop. 

 The curious and ambiguous reply by Messrs. Jackson and Alkins ''' 



^ The peat does not seem to have been broken up, but to have sunk down, 

 which goes far to support Lyell's contention that in this particular case the 

 submergence of the forest is due more to undermining of the peat than to any 

 general change in sea-level. 



" Natural History of Bournemouth, p. 63. 



3 Geol. Mag., Vol. LVI, 1919, p. 59. 



^ Ibid., p. 384. 



' Ibid., p. 430. 



