1826.] ■ which appear on th6 Yorkshire Coast, 361 



Recapitulation, 



It appears from what has been stated above, that if we descend 

 from the region of the carboniferous Hmestone and the coal 

 measures of the county of Durham, cross the plain of Cleveland, 

 and examine the deposits which present themselves along the 

 Yorkshire coast, we shall in succession pass over the following 

 formations : — 



1. Magnesian limestone, the lowest of Conybeare's superme- 

 dial order.* 



2. New red sandstone, and red marl with gypsum. 



3. Lias formation. Represented by the alum-shale, which ia 

 many of its mineralogical characters, in its great subdivisions, 

 in its geological position, and in its fossils, appears identical 

 with the lias. 



4. A newer coal formation ; but perfectly developed, and 

 immediately succeeded by the coral-rag oolite. This formation, 

 therefore, stands in the place of the whole lower division of the 

 oolite series (viz. inferior oolite, great ooUte, forest marble, corn- 

 brash, &c.), and of the Oxford clay. 



5. Coral-rag oolite. 



6. Kimmeridge clay. The denudations on the coast are here 

 imperfect ; but the Portland oohte and Purbeck limestone, the 

 Hastings sands. Weald clay, Shanklin sands, Cambridge and 

 Folkstone gait, and green-sand, appear to be wanting. 



7. Chalk formation. 



8. Traces of tertiary beds. 



9. Diluvium oi" Holderness, &c. 



Such appears to be the result of the facts detailed in the pre- 

 ceding sections of this paper. 



Trinity College, Cambridge, April\8, 1826. 



P. S. The latter part of the preceding paper was written 

 while the author was absent from the University, and in a place 

 where he had no opportunity of consulting the " Journal of the 



• It does not, in this part of England, generally appear in the conglomerate form ; 

 but it is separated from the coal measures by a very peculiar formation of sand and 

 sandstone, which is nearly co-extensive with the magnesian limestone, and therefore 

 unconformable to the coal measures. This peculiar formation, whicli ranges from the 

 southern extremity of Yorkshire into the edge of Northumberland, was lirst brought 

 into notice by iMr. Smith under the name of the Pontefract-castle rock. In the county 

 of Durham, it often appears in the form of coarse light-coloured, and almost incoherent 

 sand of extremely variable thickness. The most magnificeut exhibition of it is in the 

 banks of the Wearc, above the northern boundary of the magnesian limestone. It is 

 there of a very great thickness, and appears partly in the form of yellow incoherent sand, 

 and partly in a form exactly resembling many portions of the new red sandstone. It i» 

 not a little extraordinary that this most interesting deposit (which is likely to produce 

 very ruinous effects in shafts sunk for coal within the boundary of tlie limestone) should 

 still be almost entirely unknown to the practical men lesident in the great northern 

 coal-field. 



