GEOLOGY 



The CARBONIFEROUS LIMESTONE, with the YOREDALE SHALES, which 

 gradually replace it towards the north, was laid down over an enormous 

 area extending to the borders of Wales on the west, to the lowlands of 

 Scotland on the north, to an unknown distance to the east, but having 

 its southern margin in Leicestershire and Derbyshire on the confines of 

 Notts. In this direction it is definitely bounded by a ridge of older rocks 

 running east and west. These come to the surface in Charnwood Forest 

 and are met with in both directions in borings east and west of Leicester. 1 

 Now both the Limestone and the Shales are seen at the surface at Ticknall 

 in east Derbyshire, and if these follow the line of their common boundary 

 they will certainly enter Nottinghamshire, without any overlying Coal- 

 Measures but covered only by Neozoic strata, along a line from Remp- 

 stone to Upper Broughton. They probably occur also as basal rocks 

 throughout the whole county, but at too great a depth to be reached. 



The same may be said of the MILLSTONE GRIT which comes to the 

 surface at Melbourne and Castle Donnington. It will continue eastward 

 underground across the Soar into Nottinghamshire along a line from 

 Kingston-upon-Soar to Widmerpool. It has actually been found beneath 

 the Coal-Measures at a depth of 1,150 feet in a boring at Ruddington, 

 which was continued for a depth of 720 feet in it. 



The COAL-MEASURES, or group of strata in which are found seams of 

 coal thick enough to be profitably worked, are the lowest rocks which 

 actually come to the surface in the county, of which they occupy about 

 36 square miles. They form part however of an immense coalfield ex- 

 tending continuously into Derbyshire and Yorkshire, and formerly united 

 to the now separated coalfields of Lancashire and north Staffordshire. 

 This former union is shown by the recognized identity of the ' Black 

 Shale ' coal of Derbyshire and Notts with the ' Silkstone ' of Yorkshire 

 and the 'Arley Mine ' of Lancashire, and by the occurrence of the same 

 kinds of Upper Coal-Measures in Notts and north Staffordshire. 



The materials of which the Coal-Measures are formed consist of beds 

 of sandstone and grit of various thicknesses interspersed with beds of 

 shale or bind and occasional beds of coal and other special rocks, such 

 as clunch, gannister and ironstone. It is probably seldom realized by 

 those who have no mining experience how small is the amount of coal in 

 comparison with the rest of the series. Thus out of i ,900 feet of strata 

 from the top of the Coal-Measures to the lowest workable seam 2 pierced 

 near Nottingham only 83 feet consists of actual coal, and much of that 

 is too thin to be worked. For this reason outcrops of coal are seldom 

 or never now seen at the natural surface, but only in cuttings or in clay 

 and stone pits. 



The best idea of the Coal-Measure strata of Nottinghamshire may 

 be obtained from the cuttings on the canal side near Wollaton ; the rail- 

 way cuttings between Radford and Trowell 3 (formerly) and at Kimberley; 



1 Harrison, Pnc. Birm. Phil. Soc. vol. ii. 



3 Geol. Survey Mem. sheet 71, N.E. (3 sections). 



3 Irving, Pnc. Geol. AIIOC. vol. vi. 



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