LOCAL DETRITUS OF STAFFORDSHIRE AND WORCESTERSHIRE. 



525 



rates ; and the only other materials are referrible to the adjacent Silurian and trap rocks. 

 Although these accumulations have often a very variable aspect, I confess I am unable 

 to draw any distinctions in their age. In some places, the sands appear to occupy the 

 lowest position j in others vast masses of clay, 100 or more feet thick, the decomposed 

 shale of the coal-fields, mixed up with broken coal, grit, &c, underlie the sand; 

 and again the sand, clay and gravel are dovetailed into each other. Hence we must 

 conclude, that they all resulted from long-continued, submarine currents, which acted 

 in different directions and were influenced by the various movements of elevation and 

 disturbance to which, we know, the district was subjected. (See chapters 36 and 37.) 

 A fine section of this detritus of the Dudley field, has recently been laid open about five 

 miles from Birmingham in cutting the grand j unction rail-road. The upper part consists , 

 of from 25 to 30 feet, of foxy-coloured sand with rounded quartz pebbles, varying in bulk 

 from 4 or 5 inches, to the size of a wren's egg. This sand rests, in one part, irregularly 

 upon a mass of 60 or 70 feet of bluish clay, in which small pebbles occur at intervals, and 

 more frequently angular fragments of the coal-field ; also occasionally concretions of iron- 

 stone with small pieces of coal 1 . If the north-eastern side only of the deep cutting 

 were examined, the clay or lower portion of the deposit might be conceived to indicate 

 an earlier period of denudation ; but on further research, sand, apparently the same 

 with that which lies above the clay, is found to rise in wedge-shaped and irregular 

 masses through it, thus compelling us to assign the whole to one epoch. In this detritus, 

 I could trace no signs of the granitic or northern drift, for though the northern bowlders 

 are strewed plentifully over the surface of the eastern and northern faces of this field, 

 they are not intermixed with this local detritus. The quantity of small rounded pebbles 

 of quartz rock around certain parts of the tract is very great, particularly near Bar, and 

 thence towards Lichfield. Still larger quantities of the same pebbles are piled up on 

 the western slopes of the Clent and Higher Lickey Hills. It mast not be imagined 

 that these quartz pebbles were rounded by the action of the water which strewed this 

 detritus over the bottom of the sea. They are, in fact, evidences of the action of the 

 more ancient bodies of water, which formed the conglomerate of the New Red Sand- 

 stone, &c, their present distribution having been simply due to the disintegration of 

 those rocks, and the disturbances before alluded to 2 . 



1 In many parts of the adjacent districts drifted fragments of coal are found in the superficial detritus, and 

 these have occasionally led idle speculators to dream of coal-fields in situ. Such coa]y detritus occurs near 

 Bobbington, between Dudley and Bridgenorth, and also at Powick and other places near Worcester. At the 

 former place it covers the New Red Sandstone, at the latter the " Keuper " marl of the same system. 



2 In his memoir on the quartz rock of the Lickey Hill (Geol. Trans., vol. v. Old Series.), Dr. Buckland has 

 clearly explained, that these pebbles were rounded by ancient and not by diluvial action. He supposes, that 

 many of these quartz pebbles of the central counties, were originally derived from the little ridge of quartz 

 rock of the Lower Lickey Hills (which I have shown to be altered Caradoc sandstone), indicating, at the same 

 time, that most of them had been first formed into conglomerates of the New Red Sandstone, and afterwards 

 distributed by diluvial agency. If the present configuration of the country be considered, it would be im- 



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