THE GEOLOaiST. 



JULY, 1859. 



ON THE RED CPIALK OF ENGLAND. 



Read before the Geologists' Association, 4th April, by Rev. Thomas 

 Wiltshire, M.A., F.G.S., Etc., President. 



Persons in general take as the type or representative of chalk the 

 material which meclianics employ for tracing out rough lines and 

 figures. It is a substance of a bright white colour, somewhat yield- 

 ing to the touch, and capable of being very easily abraded or rubbed 

 down. 



But the geologist gives a much wider interpretation to the term, 

 not limiting it by these few characteristics ; and, accordingly, he 

 includes under the same title many strata which would hardly be 

 so grouped together by the uninitiated. 



For instance, there is at the base of the upper portion of the cre- 

 taceous system a certain hard, often pebbly, and highly coloured 

 band, which, notwithstanding its great departure from the popular 

 type, is nevertheless styled in geological language the "Red Chalk." 

 This stratum, the subject of the present paper, nowhere forms a mass 

 of any great thickness or extent ; perhaps if thirty feet be taken as 

 its maximum of thickness, four feet as its minimum, and one hundred 

 miles as its utmost extent in length, the truth will be arrived at. 

 It may be said, also, to be peculiar to England, for the Scaglia, 

 or Red Chalk of the Italians, has little in common with that of our 

 country. The two differ widely in appearance, in situation, and in 

 fossils. 



The first view of the seam in the north is to be obtained about 

 six miles north-west of Flamborough Head, in Yorkshire, near the 

 village of Speeton, where its structure, dip, and general appearance 

 can be remarkably well studied. 



VOL. II. X 



