Mi PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 17, 



within the limited area chosen, which may throw light on the history 

 of this peculiar type of the Oolites. This history has now acquired 

 other points of interest than those long known to belong to it. The 

 bands of ironstone which were noticed in several parts of my sec- 

 tions, and which, gathered in fragments on the beach, yielded a few 

 hundred tons of iron in a year, when transported to Newcastle, are 

 now so much explored in many of the interior hills and vales, as to 

 feed long ranges of blast-furnaces on the Tees, and send half a million 

 of tons of ore in a year to the great iron-works in the west of Dur- 

 ham, by railways which bring back in return 1 00,000 tons of iron. 

 In a few years this vast "yield " will be doubled or trebled, for the 

 iron-ore is inexhaustible, and what is now worked is much surpassed 

 in richness by some as yet only beginning to be known. 



It must not be supposed that in every part of the district the 

 Lower Oolites of Yorkshire fit themselves to any one section assumed 

 as a type of their development in the north-east of the county : on 

 the contrary, there occur great variations. Neither can the Bath 

 type of the Oolites be adapted to the Midland districts of England, 

 without some important changes. I propose to show, in the first 

 place, what are the principal differences in Yorkshire, and, by com- 

 paring these with the sections in North Lincolnshire and Oxford- 

 shire, to show how real is the connexion and how great is the varia- 

 tion of the several parts of this large Oolitic field. 



The Yorkshire coast furnishes one complete section of this series, 

 measurable in every part, which has again and again been measured 

 and remeasure.d by myself, both before and since the year 1829, the 

 year of the publication of the ' Illustrations of the Geology of York- 

 shire.' I have no material change to make in this section ; but in 

 regard of the beds at Gristhorpe, which correspond to the Bath 

 Oolite and the strata between it and Cornbrash, some details will be 

 useful which were not needed in that sera of geology. Prof. W. C, 

 Williamson * and Prof. J. Morris t have already contributed some 

 observations on this remarkable section, but they do not render it 

 undesirable for me to give measures in detail. 



Coast Sections near Scarborough. — A vertical section of the beds 

 on the Yorkshire Coast from the base of the Kimmeridge Clay to 

 the top of the Lias, taken by measure from the face of the cliffs, 

 with only the addition of the Upper Calcareous Grit in Silpho Brow, 

 which is near the coast, is about 1 1 20 feet in thickness, of which 

 420 feet belong to the Middle Oolitic formation in the subjoined 

 proportions : — 



feet. 

 Upper Calcareous Grit (not seen on the coast, but observed 



at Silpho, Pickering, Sinnington, &c.) 60H — 



Coralline Oolite 60 



Lower Calcareous Grit 80 



Oxford Clay 150 



Kelloway Rock 50 to 70 



(It is thicker in other places.) 



O.S 



"2 t- 



* Trans. Geol. Sot:. 2 ser. vol. v. p. 223; and vol. vi. p. 143; Proc. vol. ii. p. 429. 

 t Quart. Jotirn. Geol. Soc. vol. ix. p. 317- 



