174 Yellow Limestone unconformalle on three Collieries. 



-from Flaxlev-abbey to Abbeile\) is not luicoiiformable }, in some 

 places at least, &c. &;c. 



I wish next to mention, that having returned to Mr. Fauids 

 the rough Sketches of the Garforth Colliery, Map and Section, 

 which he had lent me (p. l(v ), with reduced copies thereof for his 

 careful revisioTi on the spot, and requesting answers to 17 queries 

 on the subject ; that a few days a!L;o I was favoured l)y his answer, 

 mentioning, that his valualjle Friend Mr. James Porter, of Gar- 

 forth, had first pointed out to hiu) the very interesting, although 

 nut unique circumstances of this CoUier.y, because he saj's, that 

 nearly similar observations have been made in Kippax and ia 

 Glass'-Houuhton Collieries, a few miles southward: — that he 

 had transmitted my Maj) and Queries to Mr. Porter, from wlioni 

 I might expect shortly to receive more satisfactory answers, than 

 it was at present in his power to give, res])ecting a district near 

 20 miles from his own residence. I may therefore hope to have 

 the means shortly, of bringing these important Facts more fully 

 before the public. 



I have never visited either Kippax or Glass- Houghton Col- 

 lieries, although I have made some observations on the gypseous 

 Red Marl between the Limestone Rocks at Fairburn, which is 

 between tliese places, as mentioned in your xxxixth volume, 

 p. 104 : and I cannot avoid on this occasion expressing my sur- 

 prise and regret, that neither during this excursion, nor in the 

 large mass of written information which my kind Friend ^h•. 

 Smithson collected for me, in answer to queries which he printed 

 and circulated to most of the Yorkshire Coal-Owners, &c. (and 

 wliich command and have my most grateful acknowledgements 

 to those Gentlemen) that these interesting facts were not sooner 

 made known. I can now pretty clearly see the reason, and it 

 may be of use to other observers to mention it, of my never 

 having noticed or suspected the unconformableuess of the yellow 

 Limestone to the Coal-measures, viz. the loose nature of the 

 intervening Sand or soft Rock, which will in general be found 

 mouldered down over the upper Coal-measures : otherwise, in 

 the numerous times that I have ascended and descended the edge 

 of this Limestone Rock, in various parts of its range, I must 

 have noticed this fact (if as prevalent as I now suspect it to be), 

 if the Limestone had lain inunediately on the Coal-measures. 

 I hope however, now, that the attention of those best able to elu- 

 cidate the- subject, I mean the practical Men of the district, and 

 of every other, where this Rock can be identified, will not relax, 

 until the truth, wherever it may lie, is fully established. 



It will be seen ]jy vour Readers, that Mr. Bakewell and myself 

 now concur pretty fully, as to the little or rather the negative aid 



that 



