NORTH STAFFORDSHIRE COIL-FIELD ORGANIC REMAINS. 43 



presence of a distinct series of beds of coal and ironstone of greater or less 

 value and persistency. The lowest measures contain seven seams of coal, 

 three of which are worked for local use only, but the base is occupied by a 

 most valuable bed of Hydrate, known as the Froghall ironstone. The lower 

 thick measures contain all the best and thick coals, but only one band of 

 ironstone (the Burnt Wood) of sufficient thickness or quality to be worked. 

 The upper thick measures afford a remarkable contrast, as containing nearly 

 all the workable bands of ironstone, while the upper measures contain thick 

 masses of brick clays, with a few thin seams of coal, and but one or two 

 bands of ironstone to which any attention has been paid. 



It is probably a somewhat remarkable feature in connexion with these 

 great divisions, that in no instance have the two middle groups been found 

 to contain deposits showing an extended continuous water-action of a turbulent 

 character ; but in the upper part of the lowest measures, and the top beds of 

 the upper measures occur rocks resembling in every particular those of the 

 Millstone-grit. It may, however, be mentioned that instances have come 

 under notice of the occurrence of large rounded quartz pebbles in shales and 

 ironstones, lying near the base of the upper thick measures at Apedale ; and 

 in another case a large siliceous water-worn boulder, some pounds in weight, 

 was met with at considerable depth near a fault in one of the pits of the 

 Cheadie coal-field. It not unfrequently happens, however, that large masses, 

 composed of fragments of plants, broken shells, and other organic remains, 

 intermixed with subangular pieces of ironstone, coal, and shaly sandstones, 

 cemented together by a hard paste, are met with in sinkings and workings in 

 the neighbourhood of faults, but as a ride the enormous stratigraphical 

 deposits of these fields evidence tranquillity of action extending over a very 

 long period of time. This conclusion is borne out by the nature and condi- 

 tion of the organic remains imbedded in the shales and ironstones of the 

 different measures, which are not only exceedingly numerous, but of a most 

 remarkable and interesting order ; and it may here be stated as evidence of 

 the results of an extended pakeontological inquiry, that before the commence- 

 ment of a systematic course of research with reference to the subject, the 

 known species of fish-remains were limited to the number of nine, with 

 about the same number of shells, including those of a marine type then sup- 

 posed to be confined to a single bed belonging to the lowest measures of the 

 Churnet valley and its representative at Wetley Moor. The fish-remains 

 are, however, now found to consist of from 35 to 40 genera, embracing 

 upwards of 80 species, while the mollusca range out into upwards of 22 

 genera, represented by about 60 species ; the marine forms extend at intervals 

 upwards from the lowest to the upper thick measures, while the frequent 

 occurrence of reptilian remains, and the vast number of the smaller crusta- 

 ceans indicate the extended range and variety of the organic life of these 

 fields during the period of their formation. These reptilian remains consist 

 of single internal bones, with occasionally roughly ornamented external 

 bones of the head. The range of these animals has been traced from the 

 horizon of the Stinking Coal of the lowest beds, here and there up through 

 the whole of the measures, to the chalky mine ironstone of the upper thick 

 group. They are generally found in association with fish-remains, and appear 

 to have been more numerous during the formation of the New Ironstone, the 

 Knowles, and the Brown Mine ironstones of Kidsgrove, Fenton, Longton, 

 Silverdale, and Apedale. They are, however, by no means confined to these 

 localities, traces of them being found over the greater part of the area in- 

 cluded in these fields, and also in direct association, both with shells referable 



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