UFFINGTON, DRYTON, AND OTHER COLLIERIES. 



93 



the trial shaft reached the purple schistose greywacke (Cambrian) inclined in nearly a 

 vertical position. A slight acquaintance with the mineral structure of this part of the 

 country would at once have checked the further prosecution of a work which had 

 reached the lowest rock, the fragments thrown up at the mouth of this shaft being 

 identical in structure with the adjacent rock of Haughmond Hill ; but notwithstanding 

 such palpable evidence the speculator continued to sink for fifty additional yards in these 

 ancient beds, and was surprised that no change of metal was met with, though the 

 youngest geologist would have told him that no change could occur where strata, of 

 infinitely older date than any connected with the carboniferous system, were in a vertical 

 position. To point out more clearly the folly of this and similar attempts I annex a 

 small general section of this little carboniferous patch, showing its relations to the ancient 

 and barren rocks on which it rests. (See section, PI. 29. fig. 6.) The coal strata here 

 dip north-north-west at a slight angle, and, as appears in the diagram, they are subject 

 to many faults, the chief of which run from north-north-east to south-south- west. From 

 Unington we must travel some miles to the east or south before we reach any other patch 

 of coal, the intervening tracts being occupied either by old Cambrian rocks rising to the 

 surface, or covered by the lower members of the New Red Sandstone and great accu- 

 mulations of gravel. It is probable, however, that on many points the coal has never 

 been deposited, since we occasionally see the Lower New Red Sandstone reposing 

 directly upon the older rocks. 



One small deposit is found atDryton, on the south- western slope of the Wrefcin ; and in the more 

 superficial parts of it, near Longwood, coal was long ago extracted ; but it has more recently been 

 followed to a greater depth at the former place, where two seams are now in work. The shaft is 

 thirty yards deep, eighteen of which are sunk through overlying detritus of red sand and pebbles, 

 &c. The uppermost of the beds of coal is two feet, the lowest three quarters of a yard thick, se- 

 parated by clods and sandstone, and there are no traces of the limestone or of the third bed of coal. 

 The dip is three inches in a yard to the south-east. 



On the south bank of the Severn, the bay formed in the older rocks between the ridge 

 of the Caradoc on the east, and Lyth Hill on the west, abounds with carboniferous 

 patches, which vary in the amount of their productiveness, precisely in the ratio of the 

 depth at which the underlying rock is found. For example, at Cound, Pitchford, and 

 other places, where these old rocks (Upper Cambrian) occasionally protrude to the 

 surface, the adjacent carboniferous strata are mere shreds, sometimes covered by the 

 newer Red Sandstone, but towards the centre of the trough the coal strata thicken, and 

 at Le Botwood, near Longnor, we again meet with nearly the same development as in 

 the Pontesbury field. These beds dip east-north-east 10° or away from the contiguous 

 promontories of older rocks. The shaft at Le Botwood is sixty-three yards deep, passing 

 through shales, limestone, and coal. The shale or roof of the coal is particularly rich 

 in plants, and those which I collected were identified by Professor Lindley and form part 

 of the list previously given. 



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