86 



UPPER COAL MEASURES NEAR MANCHESTER. 



Reverting to the consideration of the band of limestone above described, I may state, 

 that the geological interest attached to it has been much enhanced, by finding it in 

 various other localities near Shrewsbury, such as Nobold, Uffington, Le Botwood, &c, 

 occupying the same geological position, and interstratified with the same plant-bearing 

 shales, and seams of coal, and also by observing it, 1832, on the southern edge of the 

 great coal-field of Coalbrook Dale, where it has since been shown by Mr. J. Prestwich 

 to overlie the lower or rich coal-field of that tract, thus completely proving the zone of 

 coal measures in which the limestone occurs, to be the youngest member of the carbo- 

 niferous system, an inference indeed which I had deduced from many examples of trans- 

 ition between it and the Lower New Red Sandstone. 



Upwards of three years after I had communicated my views concerning the fresh- 

 water limestone, to the Geological Society of London, certain carboniferous rocks at 

 Ardwick near Manchester were described by Mr. W. C. "Williamson, with notices of 

 numerous fossils which he had collected, (Phil. Mag., Oct. 1836). From the silence 

 of this author concerning my observations in Shropshire, it would appear he had been 

 unacquainted with them, and had therefore no suspicion that the calcareous rocks he 

 was describing, bore any affinity to this peculiar coal measure limestone. Professor 

 Phillips having visited Manchester when the Ardwick limestone was under examina- 

 tion, was furnished by Dr. C. Phillips and Mr. Mellor with a complete general sec- 

 tion of these beds. He at once detected the little microscopic shell so abundant in 

 that limestone, and recognised it as identical with the planorboid shell of the Shrews- 

 bury rock ; and following up his inquiries, he perceived other analogies of the organic 

 remains, which had previously escaped notice. By these researches, and by examina- 

 tion of the strata, it became manifest to him, that Dr. C. Phillips had rightly asso- 

 ciated these limestones and red marls with the coal formation, and that the fossiliferous 

 and calcareous coal measures of Ardwick near Manchester, were of precisely the same 

 age as those I had described near Shrewsbury. But other zoological interest was 

 attached to this limestone ; for as, in its extension to Manchester, it was found to be of 

 greater thickness, so it also proved to be richer in organic remains than in Shropshire. 

 Collecting a number of individuals of the little planorboid shell, Professor Phillips made 

 magnified drawings of them, with which he kindly furnished me for the illustration of 

 this work, and from which some of the figures in the preceding wood-cut have been 

 taken and prepared by Mr. J. Sowerby. To make the reader fully acquainted with all 

 the contents of this limestone in Lancashire, where it is so much developed, I annex in 

 the following page a description from the pen of Professor Phillips of the organic re- 

 mains it contains at Manchester, as extracted from a letter to myself. In the mean 

 time the following is a summary of the strata in which they are imbedded, constructed 

 from the original sections of Dr. C. Phillips and Mr. Mellor, the memoir of Mr. Wil- 

 liamson, and the personal investigation of Professor Phillips. 



