234 Mr. H. Seeley on the Stratigraphical Position 



portion of the Chalk formation as those parts which are white 

 and grey. It was WiUiam Smith who gave to us this apparently 

 appropriate term, adopting it into use from the popular local 

 nomenclatui-e. Speaking of the Lower Chalk, he observes * : 

 " A singular variety, at least in appearance, of this under part 

 of the Chalk occurs in Lincolnshire, which, from a tinge of red 

 oxide of iron, is there called red chalk. The same, very highly 

 tinged with red, reappears on the opposite side of the Wash, 

 under the cliff exposed to the sea, at the N.W. point of Norfolk." 

 Five years later, Messrs. Young and Bird f, in describing the 

 Speeton cliff, remark : "At the bottom of the cliff is found an- 

 other species of chalk, which we may call the Lower or coloured 

 Chalk. It has the same grain and fracture, and the same ab- 

 sorbent qualities with the great body of the chalk ; but, instead 

 of assuming a massive appearance, with vertical fissures, it lies 

 in horizontal, or at least flat strata, generally of no great thick- 

 ness, yet tolerably compact ; and instead of a bright white colour, 

 the greater part is of a dull white, with a greenish, and in some 

 places a bluish tinge; while other parts are of a brick-red 

 colour, or rather of a duller red, approximating to chocolate. 

 The red chalk alternates with the dull white in large stripes." 



Thus, then, arguing chiefly from superposition and mineral 

 character, the relation of the red and white chalks is clearly 

 pointed out ; but the only point proven is, that below part of 

 the Lower Chalk exist certain beds of a red colour. And it was 

 not until Prof. Sedgwick, in 1826 J, noticed the beds, that a 

 suspicion arose as to their being anything other than chalk. 

 Anticipating others by more than thirty years, the Professor 

 suggests that there are two Red Chalks ; and to him belongs the 

 merit of being the first who brought to the question the aid of 

 organic remains. These pregnant observations cannot better be 

 given than in the Professor^s own words. He says : " In the 

 Chalk-marl (which at Speeton, 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 colour- 

 ing matter is less abundant. But the red beds in Hunstanton 

 Cliff, on the coast of Norfolk, do not so unequivocally belong to 

 the Chalk formation, but rather seem to represent, in a very un- 

 usual form, the Cambridge Gault ; for they exist under the Chalk 

 formation, and do not alternate with any part of it, and they 

 contain the peculiar fossils of the Gault in great abundance, and 

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

 resembling those at Shanklin in the Isle of Wight), which always 

 have their place below the Gault." 



* ' Strata Identified,' 1817. t ' Yorkshire Coast,' 1822. 



X Annals f Philosophy 



