1857.] 



PHILLIPS — OOLITE AND LIAS, YORKSHIRE. 



87 



On comparing this with the corresponding section of the south of 

 England, it may be remarked, that only near Weymouth is the 

 Upper Calcareous Grit well exhibited, and that it is there associated 

 with Kimmeridge clay, and contains, like it, Ostrea delto'idea. I have 

 seen this once in the Vale of Pickering in Yorkshire. Again we re- 

 mark the extraordinary development of Kelloway rock in Yorkshire, 

 to ten times its dimensions in Wiltshire ; while, on the other hand, 

 the Oxford clay is reduced to one-fourth of the thickness which it 

 has in the Midland Counties, and is a much more sandy and much 

 less fossiliferous deposit. We now proceed to consider the Lower 

 Oolitic formations. (See Sections 1 and 2, PL VI.) 



Section No. 1 is the well-known general section of the Lower 

 Oolitic series near Bath, as it was understood and named by Smith. 

 Section No. 2 is the corresponding series in Yorkshire. 



X 



No. 1. 



f, Cornbrash. 



{3. Hinton Sandstone. 

 2. Forest Marble. 

 1. Bradford Clay. 



d. Great Oolite. 



f Upper Fuller's-earth clays. 

 c. < Fuller' s-earth rock. 



[ Lower Fuller's-earth clays. 

 b. Inferior Oolite. 

 a. Sands over the Lias. 



No. 2. 



f. Cornbrash. 



f 3. Shales, sandstones, ironstones; 

 plants. 

 _ J 2. Shelly oolitic beds, ironstone; 

 &c. 

 1. Shales, sandstones, ironstones; 

 plants, coal, freshwater shells. 

 d. Oolite of Gristhorp. 



(Shales, sandstones, ironstones. 

 Beds of coal, plants sometimes 

 erect. 

 b. Dogger and oolitic ironstone. 

 a. Sands of Blue Wick. 



The two sections being drawn to occupy the same vertical space, 

 the enormous extension of the sandy and the great contraction of the 

 calcareous portions in Yorkshire, corresponding to the more littoral 

 character of that region, is very apparent. There is also very little 

 "clay," as the term is used in the south of England, in this section 

 in Yorkshire ; it is usually more shaly, often more sandy or even 

 streaked with sandstone laminae, so as to resemble what is called 

 "lin and woon" in Lancashire. The following observations supply 

 a few details regarding the several groups f to a. 



f. Cornbrash. — This is often not above 2 feet 6 inches thick, and 

 in this small thickness is a parting. The top is ferruginous, and 

 mostly very shelly ; the lower part is shelly, and often contains 

 root-like bodies at the bottom. Pale blue clay 4 or 5 feet below. 



In the strata (e 3) immediately below Cornbrash, clays and shales 

 predominate over sandstones for about 80 or 100 feet ; then we have 

 for the base of this series about 20 or 30 feet of sandstone, resting 

 on pale clays, full of oblique lamination, often containing fragments 

 of wood. The following is a summary of the beds as they appear 

 in Gristhorp Bay,*, south of the island, the thicknesses being some- 

 times measured, sometimes estimated. Total 121 feet 10 inches. 



* In one of my later examinations of the Gristhorp Section, I received no small 

 help from Mr. Peter Cullen. 



