292 MM. Jukes-Browne and W. R. Andrews — 



with the laws of gravity and downhill. A glacier filling the Crum- 

 mack Valley would move southward and the blocks in question 

 clinging to the west side of the valley might be stranded where they 

 are found on Norber Brow. There is no doubt that the pedestals 

 and platforms on which most of them stand, and which vary from 

 one to two feet in height, are due to the wasting away of the sur- 

 rounding limestone rock as pointed out by Prof. Hughes and Mr. 

 Mackintosh, but I quite agree with Prof. Hughes that more data 

 than are at present available would be required before any reliable 

 estimate of the time that has elapsed since the close of the Glacial 

 Period could be worked out. 



These remarks are not intended to apply to the Silurian blocks 

 above Settle, which Phillips states are 200 feet above any similar 

 rocks in the district in situ} As we did not see them or test their 

 levels, any remarks of mine would be superfluous. 



III. — The Lower Cretaceous Series of the Vale of Wardour. 

 By A. J. Jukes-Beowne, F.G.S., and Eev. "W. R. Andrews, F.G.S. 



IT has long been known that certain deposits of Lower Cretaceous 

 age lay between the Gault and the Purbeck group in the Vale 

 of Wardour, but the absence of any good open sections, along the 

 tracts where they reach the surface, has hitherto prevented geologists 

 from ascertaining the exact nature and succession of the beds. 



Dr. Fitton, whose account of the Vale of Wardour is wonderfully 

 good and accurate, distinctly recognized the existence both of 

 Wealden and Vectian (Lower Greensand), stating that certain sands, 

 containing traces of marine shells, occurred beneath the Gault and 

 above the clays which he regarded as Wealden. 



Mr. Bristow, however, when surveying the district in 1851 to 

 1853, does not seem to have obtained any evidence for the separa- 

 tion of the sands, and considered it safer to colour all the sands 

 and clays below the Gault as Wealden until clear evidence of their 

 marine origin could be obtained. Hence no Lower Greensand is 

 indicated on the Geological Survey Map. 



During last year we jointly resurveyed a portion of the ground 

 on the six inch maps, and were able to obtain evidence that proved 

 Fitton's view to be correct, and goes far towards completing our 

 knowledge of the succession in this district. 



This preliminary notice is printed by permission of the Director- 

 General of the Geological Survey. Early in 1890 a well was sunk 

 at Dinton, which gave us important information regarding the beds 

 immediately beneath the Gault. The following is an abstract 

 account of the section thus obtained. 



Feet. 



p I Yellow, brown, and blue clay (witli fossils) 21|- 



(jtAXIlt I g^jj^y j,Qgij ^i^]j a, layer of small pebbles at tbe base (fossils) 14|- 



! Brown, grey, and yellow sands, with lumps and layers of 



ferruginous sandstone 26|- 

 Light grey sandy clay, becoming darker and passing down 



into stiff black clay 7 



691 

 ^ Eivers and Mountains of Yorkshire, 1855, p. 111. 



