ic6 Sir H. C. Enolefield's Ohfervamns 



The height of Donnofe is 800 feet above low water mark. St, 

 Catherlnt*s hill is at leaft 850. Of the former I had no oppor- 

 tunity of examining accurately the thicknefs of the flrata; but at 

 St. Catherine's the flrata are as follow : 



Chalk - 250 feet 



Stone - 200 feet or perhaps not quite fo much, . 



Clay and fand 400 feet 



850 



This arrangement accounts entirely for the formation of that 

 lingular coafl called the Undercliff", which extends from Dunnofe 

 to St. C therine*s» and is compofed of the confufed fragments of the 

 upper flratum of rock which have given way and rolled down as the 

 fubflratum of chiy has been walhed away by the fea. \n moil parts 

 the procefs feems nearly at a ftand ; the coafl: being now prote^ed 

 by the fallen rocks; but at St. Catherine's great devaftation is flill 

 taking place. The earth-fall mentioned laft year was a very fmall 

 operation of this kind when compared with the relicks of former 

 eonvulfions. 



Fro'n this (hort fketch of the general pofition of the i^rata in the 

 iiland, I return to the particular fubjeft of the prefent paper. 



The chalk pit, which I am about to defcribe, is fituated on the 

 northern edge of the chalk range juft out of the viilao;e of Caril- 

 brook, and about an hundred yards beyond the divjfion of the roads 

 to Yarmouth and Shorwell. The pit is open to the eaft. The 

 ftrata of chalk are very regular, from two to five feet in thicknefs, and 

 divided by feams of flint from fix inches to nine inches in depth. 

 The flints arc, as ufual, in nodules of different fizes, from the fize of 

 the fiif to twice the fi2e of a man's head. The whole dip north- 

 ward with an inclination of at lead 67 degrees. Perpendicular 

 M!ures run through the whole from north to fouth, the fides of 



which 



