in Yorkshire, Derlyshlre, &c. 101 



ineroiis species and vast numbers of animal remains mixed 

 ivilh its vegetal rtynains, and as containing hut one seam 

 (if Coals, and that a thin one, rarely amounting to 9 inches 

 thick, and never exceeding 18 inches, as I beheve, after a 

 pretty extensive inquiry : though there is often a partial 

 layer of wood-coal a good deal btlow it. 



Tlie aecount of Mr. Edward Martin's South-Wales Mi- 

 neral-basin has, I observe, been by a mistake in the note m 

 the Philosophical 'i'ransactions, and p. 28 of your last num- 

 ber, referred to the volume for 1808 instead of 1806. 



From all that I had read or heard, respecting; the northern 

 termination of the valuable Coal-field of the West Riding 

 of Yorkshire, some distance N of Bradford, Leeds, &c. and 

 hearing how nmch wider this field was W and NE (Irotu 

 Halifax to Frvston-Hall near Ferrvbridne) at no trreat di- 

 stance before its termination, than it is anywhere S of this 

 in Derbyshire : I rather too hastily (as it now appears) con- 

 cluded, that the zigzag fault (Derby Report i. p. 168, and 

 p. 32 of your last number) was diminishing northward in 

 Yorkshire, or the rise becoming kss on its W side, and 

 that it would soon terminate, so as to admit a coiiiplele and 

 more extensive series of Coal-measures basfjcting, in regular 

 succession, about the parallels of Leeds and Wakefield than 

 I had seen, as hinted p. 176 of my Report: and that in 

 consequence there must have been & fault, unconnected 

 with this zigzag fault, that ranged E and W about the 

 course of the Wharf River, &c. (p. 30 of your last num- 

 ber), against which the several Grit- stone Rocks and Coal- 

 shales abutted, nearly at right angles: on examining the 

 country about Wakefield and Leeds and NEof it las^t August, 

 I find however these facts to be very materially different, 

 and that the zigzag fault continues northwaid of Dinning- 

 ton (where it is shown m the Map in your last number) to 

 increase and act a still more important part in the structure 

 of the country, than it has done south of this- its route 

 l)robably being, near to Hooton-Roberts, Clayton, Feather- 

 stone, Casiletord, Church-Garforth, Barwick m Elmet, 

 'i'horntr, Bardsea W, Easi-Keswick W, Sicklin<:hal!, &c. ; 

 and perhaps, if the 'i'ellow Lime continues much further 

 northward? it may coiitinue to follow its western edge un- 

 til almost arrived at the Tees, and then diverge from it west- 

 ward to let out the Newcastle Coal-field, as has been already 

 hinted, page 9<j. 



Those three remarkable and characteristic strata, takeix 



in connection, the coarse 3d Grit Rock of Freestone, the 



G 3 tluck 



