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THE GEOLOGIST. 



The deposition of the Oolitic and Lias formations, unlike that of 

 the Coal-measures and New Red Sandstone, was evidently continous, 

 and is without any traces of an interval elapsing between. In pro- 

 portion, therefore, as we find the transition from one to the other more 

 gradual and undefined, we may regard the section as more perfect and 

 complete. At the head of Fryup Dale, for example, we find the tran- 

 sition line far less marked than at Roseberry and most other places ; 

 and therefore we may assume that it is a more perfect section than 

 the others. The basement-bed of the Inferior Oolite has, in the south 

 of England, been the object of a contest between Dr. Wright on behalf 

 of the Lias, and Professor Buckman for the Oolites, as may be seen 

 in a paper read by the latter before the Geological Society.* I shall, 

 however, here content myself by merely stating that there are reasons, 

 which I cannot now spare space to adduce, for regarding the next 

 important stratum, as it sometimes appears as the lowest member of 

 the inferior Oolite. 



e, There is no bed amongst all which I have described, which varies 

 so much in so short a distance, as the lowest bed of the division 

 which I have before termed the "Inferior Oolite and ferruginous 

 beds." They give an aggregate of about seventy feet at many points 

 in the district. This is, at one place a vast iron-rock of thirty-two 

 feet in thickness, and at another a mere silico-ferruginous mass of no 

 commercial value. At many places, as for instance at Eston, Hutton, 

 Lowcross, Fryup, and Grosmont, its importance may be said to be 

 almost in inverse proportion to that of the lower, or " Pecten-seam," 

 in consequence of its being geologically higher up than the other 

 seam, which is often called the " Eston-seam," from having been first 

 opened out near a village of that name : this band we now speak of 

 is commonly called the "top seam," although improperly, as a higher 

 one still has been wrought. The " Oolitic seam," as I shall now call it, 

 is worked on the east near Staithes, and at Beck Hole in the Gros- 

 mont district, and at Rosedale in the interior of the country. Near 

 Staithes it assumes a compact and argillaceous appearance, and is at 

 the best part about four feet thick. At Beck Hole it is not less than 

 fifteen feet thick, and has a more open and oolitic structure, and in 

 appearance more resembles the Lias seam at Eston. At Bosedale its 

 character is again changed, and it has become a vast oolitic iron-rock 

 thirty-two feet thick, attractable by the magnet, and yielding, as a 

 maximum, nearly fifty per cent, of metallic iron. To develope this 

 invaluable deposit, a line of railway is now being made across the 

 moorland heights, from near Ingleby Greenhow on the North York- 

 shire Railway — a distance of about ten miles. To account for, if I 

 may use the term, the metallic richness and the great thickness of 

 this Roscdale iron-rock, has long been a puzzle to many of the local 

 geologists, who have thought its value and extent less than some 

 anticipate. At the quarry, indeed, where most have observed it, and 

 where it was primarily opened out as " metal" for the roads, — rich 



* Proc. Geol. Soc, Quarterly Journal, vol. xii., p. 292, and vol. xiv., p. 98. 



