42 BAKERS NORTH YORKSHIRli 



Close of the Mesozoic Age. — It is evident that during the 

 deposition of all these Oolitic strata the sea bed on the east of 

 the Palaeozoic hills was many times upraised and depressed, 

 for although the great mass of this wide range of deposits is of 

 marine origin, yet in some places there are, amongst the fossils 

 which they contain, evident tokens that land was sometimes 

 elevated above the surface of the waters in the tract where and 

 whilst these beds were in the course of accumulation. In the 

 East Riding there are marks of a considerable elevation of the 

 surface, which must have taken place towards the close of the 

 Oolitic era. A line of anticlinal axis runs from east to west 

 and the beds slope from this line both towards the north and 

 south. Upon the Oolitic strata the Chalk of the Wold hills 

 rests unconformably in the same way that we have already seen 

 the Magnesian Limestone resting upon the deposits of the 

 Carboniferous system ; and before the Chalk was deposited 

 there has evidently been a considerable waste of the elevated 

 Oolite, for in some places along the line of anticlinal axis the 

 upper beds are altogether swept away and the Chalk is placed 

 in juxta-position with the Lias. As we have it in Yorkshire the 

 Chalk is entirely a marine deposit, but there is none of it 

 within the limits of the North Riding. 



Quaternary Part of Kainozoic Age. 



PLEISTOCENE SYSTEM. 



The Glacial Beds. — For a long time during the early part of 

 the Tertiary period we may suppose the general contour of 

 the surface of our district to have been very much as it is now, 

 the vale of Pickering an arm of the sea, the central valley also 

 submerged, and on the east and west of this broad gulf a mass 

 of elevated land rising above them in the same way that the 

 two moorland ranges rise now. Of the beds of the Eocene 

 system down to those of a much later date we have no traces 

 in North Yorkshire, though the shelly deposit at Bridlington 



