508 



THE WONDERS OF GEOLOGY. Lect. V. 



the fossils of the "Wealden and those of Stonesfield, and the 

 result appeared in my first work on the Geology of Sussex, 

 in 1822.* A valuable memoir by Dr. Buckland, on the 

 fossil reptile of Stonesfield, the Megalosaurus,t again drew 

 attention to these interesting deposits, and it was ex- 

 pected that this distinguished philosopher would follow 

 up the investigation, and give a full description of the 

 organic remains. 



The Stonesfield strata have been ascertained, by Mr. 

 Lonsdale, to belong to the lower division of the Great 

 Oolite ; the following account, by Dr. Fitton, J explains the 

 circumstances under which they occur. " In crossing the 

 country from Oxford to Stonesfield, the Oxford clay, with 

 its characteristic fossils, is first observed ; this is succeeded 

 by the Cornbrash, the uppermost stratum of the great 

 oolite group, which is seen beneath the clay in several 

 quarries on the road -side between Woodstock and Blenheim. 

 The village of Stonesfield is situated on the brow of a 

 valley, both sides of which are deeply excavated by the 

 shafts and galleries that have been constructed for the 

 extraction of the slate. The beds that supply the stone 

 are at a depth of about fifty feet below the summit, and are 

 worked by shafts. The upper twenty-five feet consist of 

 clays alternating with calcareous stone ; the lower of fine- 

 grained oolitic limestone, with numerous casts of shells." 

 From the bottom of the shaft, a drift or horizontal excava- 

 tion is made around, extending as far as safety will permit ; 

 the beds above being supported by piles of the less valuable 

 materials. The strata thus worked do not exceed six feet 

 in thickness ; they consist of rubbly stone, with sand im- 

 bedding large concretional masses of fine sandy grit, which, 



* Illustrations of the Geology of Sussex, p. 37 

 f Geological Transactions, vol. i. Xcav Series. 

 X Zoological Journal, vol. iii. p. 416. 



