6 



ON THE RED CHALK OF ENGLAND. 



in the City of London, could imagine, unless he had seen the fact 

 for himself, when sewers were opened, or foundations cut, that he 

 was dwelling over beds of gravel as bright and yellow as any that 

 cover the paths of a flower-garden 1 



When, therefore, the nature of the surface of the ground is such 

 that the eyes cannot detect traces of any particular formation we 

 may be in search of, we must seek other testimony, we must ask 

 what have other men seen, and what have they recorded, and in 

 whose custody have they placed the keeping of those facts. 



In the present case I can refer to two excellent works, to help 

 us, — Professor Phillips' Geology of Yorkshire, and Young and Bird's 

 Survey of the Yorkshire Coast. 



Let us turn to the latter. The authors write that in the year 

 1819 a Mr. George Rivis, of Sherburn, bored for coal in a deep 

 dale about a mile and a half south of Staxton ; the boring was con- 

 tinued for some considerable depth. First they passed through the 

 White Chalk, next came upon the Red seam, and finally, at the depth 

 of 288 feet from the mouth of the bore, reached the Speeton clay. 

 Thus then near Staxton, a few miles west of Speeton, the Red 

 Chalk exists ; there it is, though it may not be visible. 



If we proceed still farther west along the northern foot of the 

 Yorkshire Wolds, it is possible that at Knapton we shall actually see 

 the Red and White Chalk again in situ ; for Young and Bird tell us 

 that, at a clay-pit near that village, it was to be seen in their day. 

 At North Grimston, they add, the coloured chalk seems to be wanting, 

 for at a copious spring issuing on the hill-side, about a mile above the 

 village, the White Chalk is seen lying immediately over the blue clay. 



This statement is not to be wondered at. Look at the map (page 

 2). Not far from North Grimston there must evidently be great 

 unconformity of strata. Notice several of the formations, instead of 

 running parallel to one another, actually are at right angles. For 

 instance, we have the Speeton clay, the oolites, and the lias, almost 

 perpendicular in direction to the White Chalk, a little to the west of 

 Great Driffield. Such a condition of affairs must have resulted from 

 great disturbances, and there would be nothing strange in a part of 

 the series being displaced or altogether wanting. 



Some miles to the south, near the town of Pocklington, the strata 



