A HISTORY OF STAFFORDSHIRE 



CARBONIFEROUS SYSTEM 



We have seen that the geological history of Staffordshire presents, 

 in the absence of the Old Red Sandstone, one of those tantalizing breaks 

 so frequent in the imperfect record of the rocks. The missing chapters 

 are found in Worcestershire, Herefordshire, and in South Wales, where 

 the lacustrine deposits of the Old Red Sandstone indicate an elevation 

 of the Silurian sea floor and the subsequent formation of large fresh- 

 water lakes. So great was the time represented by the missing period 

 that the fauna of the Carboniferous strata the next group met with 

 has a totally distinct aspect : many new orders, many new genera 

 make their appearance, while the species differ from those of the Silurian 

 seas ; the vertebrata have increased in numbers and are very much 

 more highly organized. 



The Carboniferous system commences abruptly with the marine 

 conditions of the richly fossiliferous Mountain Limestone of North 

 Staffordshire, when the ocean waters were warm and clear, and coral 

 reefs, on which flourished a prolific marine fauna, extended their fringes 

 along the coast line. A large river then appears to have entered the sea 

 driving away the corals and many other life forms, and laying down first 

 the muds and grits of the Pendleside Series, and then the grits and shales 

 of the Millstone Grit period. Ultimately a delta appears to have been 

 formed in which, or along its margins, the muds, shales, sandstones and 

 numerous seams of coal constituting the Coal-measures, were deposited. 



The Carboniferous rocks stand out boldly above the Triassic plain 

 in the North and South Staffordshire Coalfields. Though separated from 

 each other by the intervening red strata, it is now almost beyond dispute 

 that these isolated coalfields are connected underground. Local inter- 

 ruptions there may be, such as are shown at the surface in the Silurian 

 hills of Dudley and Walsall, but recent borings and shaft-sinkings to the 

 east and west of the present outline of the South Staffordshire Coalfield 

 prove conclusively the extension of the Coal-measures in these directions; 

 while the identity of the Coal-measure sequence as a whole in North and 

 South Staffordshire is strongly in favour of the sediments having been 

 deposited in the same basin. 



The exact nature of the pre-carboniferous floor has not been ascer- 

 tained, but the thinning away and final disappearance of the individual 

 members of the system, when traced from the north-north-west to the 

 south-south-east, shows it to have sloped rapidly upwards to the south- 

 south-east, and at a still greater rate due south. Thus the southern area 

 appears to have lain above water during the long period represented by 

 the great thicknesses of the Carboniferous Limestone, Pendleside Series 

 and Millstone Grits of the north, and not to have been submerged until 

 Coal-measure times. 



The filling up of the basin and its submergence does not appear to 

 have been a simple process, for a study of the Carboniferous rocks of the 

 Midlands, especially in North Staffordshire, clearly shows that the period 



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