24 
BLAKE : EAST YORKSHIRE. 
rather more obscure, as gathered from what is absent rather 
than from what is present. 
I have suggested that the coral reefs whence the coralline 
oolite was derived might have stood on the Pickering valley ; 
but this requires some explanation. By what has been 
already noticed respecting the older Oolitic rocks, it is seen 
that this is somewhere not far removed from the line of 
minimum deposition, so that the sea bottom would represent 
somewhat of a basin-shaped area, and it would be round the 
edges of this that coral growth would nourish, taking a wider 
and wider circle round the vale as the base went down. Thus, 
from the wearing away of the old coral reefs, and then spread- 
ing outwards, the more central portion would be left weaker, 
like a lagoon, and perhaps entirely deprived of its original 
coral growths. Whether any such is to be found beneath the 
Kimmeridge clay of the vale of Pickering yet remains to be 
proved. In any case, this central line from east to west, after 
the deposition of the Kimmeridge clay, was one of weakness, 
not of strength ; and when the great upheaving forces once 
more came into action, and the whole of East Yorkshire was 
raised above the level of the sea, the massive gave way here, 
and produced along the vale of Pickering, westward to 
Coxwold and Topcliffe, that scene of wild geological confusion 
which has long been, and long will be, a puzzle to students 
to understand. Along the north side is a great Fault, and 
along the south side is a great Fault, or more than one, 
and into the huge cleft the Kimmeridge clay sank bodily 
down. But for that deposit the vale of Pickering would 
be a fearful chasm, with precipitous sides, 500 feet in 
depth. On going west, where the great dislocation strug- 
gled with harder rocks, they were tipped over on their 
edges and let down into the gulf below, and thus we find 
— here a piece of calcareous grit, here a piece of Inferior 
Oolite surrounded by the clays of the Lower Lias, and 
