MR. E. W. BINNEY ON THE OMGIN OF IRONSTONES.. 36 



The strata above described belong^ to the lower coal field ; 

 and the 2 feet coal I consider to be identical in position with 

 the New Mills coal, so extensively worked in the west of 

 Derbyshire; whilst the rough rock is the same stone as that 

 at Werneth Low.* The small coal of 8 inches I did not see 

 myself, but was only told of its existence by a collier. 



The coal above and the coarse rock below appear to be 

 good guides in searching for the ironstone, which has been 

 proved to extend to a considerable distance, although of 

 variable thickness, and generally under that found at Mr. 

 Bishop's works, previously described. 



The rough rock, as well as being of the same age as that 

 of Werneth Low, appears to me to be in the same position as 

 those of Bagnall Church, Bolledge, and Wetley Moor. 



The composition of the ironstone taken from the middle of 

 Mr. Bishop's seam, according to the analysis of Dr. R. Angus 

 Smith, F.C.S., our excellent secretary, to whom I am 

 indebted for the trouble he has taken in making the same, is 

 as follows : 



Peroxide of iron (58.610 



Silica 6.490 



Carbonate of lime 18.170 



Carbonate of magnesia 3.723 



Manganese, alumina, and moisture 4.007 



100.000 



The stone is of a brownish red colour, and has a slaty 

 fracture parallel to its lines of deposition. Its cross fracture 

 is rough and uneven. When smoothed, the face of the stone 

 presents a finely laminated structure, the red parts being 

 divided by belts and patches of a blackish colour. Its 

 surface, parallel to the planes of deposition, frequently pre- 

 sents a blackish appearance, much resembling the protoxide 

 of manganese. The 10 inches in the middle portion of the 



• See section of the Lower Coal Field, Vol. X. (New Scries) of the Society's 

 Memoirs, p. 187. 



