90 
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 intei-val elapsing between. In pro- 
portion, therefore, as we find the transition from one to the other more 
gradual and undefined, we may regai'd the section as more perfect and 
complete. At the head of Fryup Dale, for example, we find the ti-an- 
sition line far less mai'ked 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 tenned the "Inferior Oolite and feiTuginous 
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-feiTuginous 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 fii^st 
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 wiwght. 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. N'ear 
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 Rosedale its 
character is again changed, and it has become a vast oolitic ii'on-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 gTeat thickness of 
this Rosedale 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 obsei'ved 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. 
