266 
THE GEOLOGIST. 
iu the City of Londou, 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 Slierburn, 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 Kuapton 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 Grimstou, 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 
262). 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 iu a part of 
the series being displaced or altogether wanting. 
Some miles to the south, near the town of Pocklington, the strata 
