90 ME. W. J. CLARKE ON THE ITNCONFOEMITT IN THE [Feb. IQOI, 



and i£ the section be extended so as to include the Hadley and 

 Wombridge district, which is the deepest portion and consequently 

 forms the axis of the syncline, three more seams of coal and two 

 more beds of ironstone (namely the Pungus Coal Group, belonging 

 to the Middle Coal-Measures) are found, over and above those met 

 with in the axis of the Madeley syncline. The extension of this 

 section beyond Hadley, so as to include the other and steeper horn 

 of the curve, is prevented by the interposition of the north-western 

 boundary- fault of the Coalbrookdale Coalfield, cutting off the coal- 

 seams and bringing in the Bunter Sandstone in their place. This 

 fault, with a downthrow of great extent, is a continuation of 

 the Church Stretton Fault. Fortunately, however, the direction 

 of this fault, and the anticlinal axis of which we are in search, do 

 not run quite parallel, but intersect at a very acute angle in the 

 neighbourhood of Donnington Wood. Thence past Muxton Bridge 

 to the trial-pit at Lilleshall, the Middle Coal-Measures are found to 

 rise sharply north-north-westward, as in the Madeley district. 



At Donnington and Muxton Bridge, however, the Upper Coal- 

 Measures are wanting, having been denuded away, but at Lilleshall 

 Trial Pit, Granville, Woodhouse, and Stafford Pits they are in their 

 usual position. Therefore, a section drawn through the Coalfield, 

 from Lilleshall across these pits to the Stafford, again shows the 

 same unsymmetrical syncline as that exhibited in our former sections, 

 but on a larger scale. 



In passing, I wish to make the suggestion that the Granville section, 

 the best developed in the Coalbrookdale Coalfield, does not (in my 

 opinion) represent the fullest development of the Middle Coal- 

 Measures originally attained in Shropshire. I surmise that originally 

 this coalfield approximated very nearly to the extraordinary 

 thickness of the North Staffordshire Coalfield from the Bassey Mine 

 downward. The evidence for this view is not, 1 confess, conclusive, 

 resting chiefly on these two facts : firstly, the gradual increase in 

 number of the beds of coal and ironstone coming in under the Upper 

 (red) Measures as we proceed from south to north ; and secondly, 

 the existence of a Spirorhis-limestone above the Bassey Mine at 

 Fenton. 



Retracing our steps to the Coalbrookdale field we find another 

 little coal-basin, namely, the Inett-Caughley basin, again forming 

 an unsymmetrical syncline on a small scale, of exactly the same 

 type as that at Madeley. The Upper (red) Measures cut out all the 

 productive Middle Coal-Measures on the ridges of the containing 

 anticlines. The bounding anticlines were all mentioned by Prestwich 

 in his famous memoir on the Coalbrookdale Coalfield, and it appears 

 to me singular that their full significance has not been realized ; to 

 my mind they constitute the key to the whole problem. 



Passing over the intermediate ground between here and the 

 Porest-of-Wyre Coalfield, two facts are worthy of notice : firstly, 

 that at Eardington Deep Pit the Upper Measures repose directly on 

 Devonian strata, and if my theory is correct we must regard this 



