348 



Notices respecting New Books. 



"In the following table, they are numbered according to the gene- 

 ral series of Yorkshire strata, pages 32, 33. 



Greatest observed Thickness. 

 Feet. 



10 Impure, sometimes oolitic limestone, full of 

 shells. (The cornbrash of geologists.) 



200 1 1 Sandstone, shale, ironstone, and coal,with car- 

 bonized wood, ferns, and other fossil plants. 



30 12 Impure, often oolitic limestone and ironstone, 

 with many fossil shells. (Oolite of Bath.) 



500 13 Sandstone, shale, and coal, with carbonized 

 fossil plants. 



CO 1 4 Subcalcareous, irony sandstone, often contain- 

 ing shells, called dogger. (Inferior oolite of 

 Somersetshire.) 



200 f 1 5 Upper lias shale, or alum shale, with nodules of 

 argillaceous limestone, ammonites, belem- 

 nites, &c. (Blue marl of Northamptonshire.) 



150 J 16 Ironstone and sandstone strata, with terebra- 

 tulae, pectines, cardia, aviculse, &c. (Marl- 

 stone of Northamptonshire, &c.) 



500 17 Lower lias shale, with gryphseae, pinnae, plagi- 

 ostomse, &c. (Lias shale of Somersetshire)." 



On comparing this section and the enlarged descriptions of the 

 lias and oolitic formations of Yorkshire with that of the vicinity of 

 Bath, we obtain the following important conclusions : 



1st. That the calcareous portion of the lias of Yorkshire is much 

 less decidedly accumulated into solid limestone rock than about 

 Bath, and in this respect the Lincolnshire lias possesses an interme- 

 diate character. 



2dly. That the marlstone beds, which, though well distinguished by 

 Smith, seldom appear in much force near Bath, and then only twenty 

 feet below the sand of the inferior oolite, are in Rutlandshire buried 

 one hundred feet below that rock, and are covered inYorkshire by a 

 thickness of two hundred feet of alum shale. 



3dly. That the yellow or brown sand and sandstone, which near 

 Bath separates the inferior oolite from the lias, is continuous through 

 the counties of Rutland and Lincoln into Yorkshire, where it is 

 scarcely accompanied by any trace of oolite. 



4thly. That instead of the shelly calcareo-argillaceous series 

 (Fullers-earth beds, Smith) of beds which divides the Bath oolite into 

 great or upper and lower, or ferruginous oolite, the Yorkshire hills 

 contain fully five hundred feet of sandstone and shale with a vast va- 

 riety of fossil plants, and thin seams of coal ; and that between the 

 great oolite and the cornbrash, a similar interposition of sandstone 

 shale and coal-plants is repeated. The Bath oolite formation is 

 therefore in Yorkshire a true coal-field, and must never be left out of 

 consideration in any speculations on the origin of coal seams. 



Mr. Murchison's researches in Sutherland show how fur northward 

 this coal-field reaches, and there are several similar examples in Ger- 

 many ; 



