Yorkshire Oolites. 195 



old soil, charged with the roots of those plants, the 

 decay of which on the spot formed the thin beds of coal, 

 just in the manner that coal-beds were formed during 

 the Coal-measure epoch, but, in the case of these Oolitic 

 coal-beds, on a much smaller scale. 



Above these fresh-water and terrestrial strata, there 

 occur beds of < grey limestone ' and shales. It is often 

 called the Scarborough Limestone, and is full of marine 

 shells, &c., common in the ordinary Inferior Oolite. 

 Finally, on the top of this, there are strata of sand- 

 stones and shales, often called the upper series, to 

 distinguish them from the lower sandstones and 

 shales that lie below the grey marine limestone. Like 

 the lower series, they seem to contain no mollusca of any 

 kind, and, indeed, the only fossils that have been found 

 in them are the remains of plants scattered through 

 the rocks, accompanied here and there by streaks of 

 coaly matter. On the whole, such evidence as there is, 

 tends to show that these also are fresh-water or at 

 most estuarine strata. 



Overlying these sands, there is a persistent band of 

 impure limestone, generally from 3 to 6 feet thick, 

 which is considered to represent the Cornbrash of 

 more southern areas, where, it will be remembered, it 

 lies directly on strata of the Great Oolite series. It is 

 certain that in its fossils it is intimately related both to 

 the Great and the Inferior Oolite, including the Fuller's 

 Earth. If, therefore, we take the Lower Oolites as a 

 whole, the most philosophical method of regarding them 

 is to consider them as one. Owing to minor changes in 

 the physical geography of the sea bottom, and of the 

 neighbouring land, this formation was, during the pro- 

 gress of deposition, locally broken up into a series of 

 subformations, now of limestone, now of clay, now of 



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