S42 Prof. Sedgwick on the Classification of the Strata [May, 



Sect. 3. — Chalk of Flamborough Head and the Wolds* 

 The chalk undoubtedly forms the foundation on which rest all 

 the beds described in the last section. All its characters are 

 exhibited in a succession of lofty and finely indented escarp- 

 ments which extend from Bridlington, round Flamborough Head, 

 to Speeton. It is, with few exceptions, more compact than the 

 corresponding beds in the southern parts of England ; and the 

 imbedded flint nodules are generally more compressed, often 

 putting on the appearance of large tabular masses, which are 

 striated parallel to the planes of stratification. These flints are 

 of an unusually pale colour, and exactly resemble specimens 

 derived from the chalk in several parts of France. In the chalk 

 marl (which here, as in other parts of England, exists near the 

 bottom of the formation), are many beds of a bright red colour, 

 which alternate with others where the colouring matter is less 

 abundant. This group gives a very singular character to the 

 lower portion of the chff", especially near Speeton.f 



A striking phenomenon connected with this formation, and 

 not, I believe, noticed in any geological work, may be seen in 

 the lofty cliff" about half way between Flamborough Head and 

 Speeton. The beds of chalk and flint are at once bent out of 

 their ordinary position, and twisted into a number of curves, the 

 flexures of which are as violent and irregular as those which 

 commonly occur in formations of greywacke. The cause which 

 produced this very singular irregularity must have acted par- 

 tially ; for in the remaining part of the cliff", the beds of chalk 

 and flint have their usual direction and inclination. 



Notwithstanding the anomalies which are above stated, the 

 chalk formation of the Yorkshire coast agrees in all its general 

 characters with the same formation in other parts of England, 

 admits of the same subdivisions, and contains the same suite of 

 organic remains. Exclusively, therefore, of the fact of actual 

 continuity, the several parts of the formation just described, 

 must be considered, by everyone who is capable of appreciating 

 physical evidence, to be contemporaneous with the several parts 

 of the same formation in the southern districts of our island. 



S F. c T . 4. — Vale of Pickering. 

 The whole of the low region stretching through the vale of 



* For a detailed description of this formation, I must refer to the " Geological Sur- 

 vey of the Yorkshire Coast," (p. 46 — 55). Its superficial extent may be seen in any of 

 our geological maps. 



-|- The red beds in Hunstanton cliff on the coast of Norfolk (which I had the advan- 

 tage of examining last spring in the company of Dr. Fitton) do not so unequivocally 

 belong to the chalk formation, but rather seem to represent, in a very unusual form, the 

 Cambridge gall ; for they exist under the chalk formation, and do not alternate with 

 any part of it ; and they contain the peculiar fossils of the gall in great abundance, and 

 are seen to repose on the green and ferruginous sands (exactly resembling those af 

 Shanklin, in the Isle of Wight), which always have their place below the gait. 



