Answers to Mr. IVinch's Geological Queries. 25 1 



I will however add, that in most instances, as has been done 

 about Lvth*, those wlio have with effect studied the Stnithiau 

 principles of Mineral Survevino;, will be at no loss to subdivide 

 Mr. Smith's " clunch clav," into several Strata, and distinctly 

 show their continuous ranges on a Map of sufficient scale, with 

 Sections in anv direction, &c.; and by means chiefly of the fossil 

 Shells species, rather than by tiie precise Mineral species (by 

 which " formations" are usuallv and solely attem-pted to be iden- 

 tified) to identify the same (as Mr. Smith has done) in situations 

 too distant, or which are too much intersected by f/nills, or by 

 alluvial or uncnvfdrmahly overlieing Marl patclies, for eac!i stra- 

 tum to be actually traced in connection on the surface. Sec 

 my paper on Fossil Shells, vol. xlv. p. 274. 



2d. I have never visited Thirkelhv, or made any observations 

 myself, in the small Coal-Hsld to the E and SE of Thirsl; ; but 

 from various notes of the inquiries I have made concernii'.g the 

 strata of the vicinity of Tiiirkelbv, I can entertain few doubts, 

 of the blue shellv Limestone of that place, being one of several 

 thin Rocks of shellv Limestone f, which lie between the upper 

 and better part of the Alum-shale and the thick, harder and 

 useless lower part of that series ; which last would more pro- 

 perly be denominated Bind with Stone beds, than Alum- shale : 

 I have seen these Limestones, at the SE corner of Staitii's Bay 

 NW of Whitliy, from the top of the cliffs over Boulby Tunnel, 

 on the W of StaithsbeckFuIling-mill, at Blue-Bank, and in ether 

 cliffs by the Esk River, and I can entertain no doubt that I 

 should be able to trace these, wherever alluvia or unconformable 

 Red Marl is absent or deranging faults do not intervene, in a con- 

 tinued course, to the vicinity of Thirkelby, and thence forward, 

 into and across the eastern part of Lincohi'^hire. 



I heartilv wish that Mr. Buckland or Mr. Frver, the latter 

 Gentleman in particular, because he is locally resident, and has 

 at this time the whole of Northumberland and Cuml)erland un- 

 der his Survev, for publishing inijiroved Maps of these Counties, 

 would carcfullv, and without reference to any Tiieories, consider 

 my five heads of (jucries in your February number, and those 

 which now follow in continuation, and communicate through 

 your pages, all the precise facts they can, which have reference 

 to them. 



* The Writer thinks it prohnhic tli:it Mr. Wincli rni!;ht, (in npplicntion 

 to John M. ^'nvorbv, l"".si| of l.ytii Hall, h:\vc iiCiJ'SS lu ;i i\linir;il Map 

 and llcport on tins district, tnaiie in lUl 1 hy Mr. Farty, which would some- 

 what assist hit inijniries un tiiis head. 



t It );is often struck nie, but leisure Inis never permitted of rmiijuiring 

 the n'lelh, that these sIk lly Limestones, answer to the higher beds of the 

 Brrljord ur Conibrush Limestone Series, of Siuith's Map. 



(■). In 



