STUDLAND. 



399 



sition thus mentioned, is Dr. Mitchell's remark that "there is 

 a spot beyond the boundaries " of his paper, " where such 

 flints are exceedingly abundant, which is the hill immediate- 

 ly above the fire-stone quarries, a mile north from Godstone 

 Green"— (p. 219) Now the fire -si one is the lower green 

 sand, and at Godstone the pits occur in the side of the chalk 

 escarpment of Tillingdown, having opposite to them, at little 

 more than two miles distance to the south, the elevated ridge 

 of Tilbuster Hill, which consists of chert, and the summit of 

 which is nearly on a level with the chalk downs. 



The subjoined section (P) is given to point out the pecu- 



Tilbuster Hill. 

 / 



Section and faults at Tilbuster Hill, near Godstone, Surrey. 

 1, Sand and loam. 2, Grey sand. 3, Chalk. 4, Grey sand. 5, Sand and 



iron stone. 



6, Weald clay. 



liar position of the chert beds, | which are, in some places, 

 perfectly fragmentary, so near to the locality where the peb- 

 bles are found ; and which I cannot help thinking supplied 

 them. Should further examination lead to the conviction, 

 that the pebbles above the fire-*tone did come from Tilbuster, 

 or the beds to which that hill belongs, there is no reason to 

 deny, that the chert of Surrey was once perfectly sufficient in 

 extent to have supplied all the beds of transported rolled 

 fragments that form the accumulations at Croydon, Black- 

 heath, &c. 



Having suggested the above possible origin for the pebbles 

 of the early tertiary epoch, it remains to say a word as to the 

 method of their accumulation. This strikes me to have been 

 occasioned by the very same causes that now produce shin- 

 gle-banks and beaches on and near the shores of our present 

 seas, — currents and agitations of the tidal waters, whether of 

 the ocean or its estuaries. That this is probable is shown by 

 the fact, that these pebbles are not universally scattered over 

 the surface of the chalk, but only on such places (where found 

 in situ) as at once justify the idea of an ancient littoral accu- 



1 A sketch of Tilbuster (Tilburstow or Tilvester) Hill is given by Dr. Fit- 

 ton, G. T. iv. 138, and a description by Dr. Mantell, Geol. S.E. of Engl, 

 p. 177. 



Vol. III.— No. 32. n. s. 2t 



