future Extension of the English Coal-fields. 347 



probably joins on to the great Derbyshire anticlinal in this di- 

 rection. If so, we must necessarily look for the prolongation 

 of the Nottingham coal-field to the east of a line drawn from 

 Derby through Chain wood Forest and the insulated hum- 

 mocks of the same sienitic chain ranging along the west 

 bank of the Soar nearly to its source. The valley of the Soar 

 below Leicester will sufficiently indicate the most probable 

 line of the extension of the carboniferous deposits; and in this 

 Journal for May 1829 (p. 347.), Mr. Forster has already com- 

 municated some account of this district, from which it appears 

 that traces indicating coal have been observed atBirstall on the 

 Soar, in this quarter : but still as the whole surface is covered, 

 and as the substrata are effectually concealed by the overlying 

 horizontal deposits of red marl, the only prudent mode of 

 proceeding would be to attempt to trace this hidden outcrop 

 of the coal-measures from the known Nottingham coal-field 

 on the north, and to pursue it thence to the south by a re- 

 gular series of borings. The Charnwood anticlinal line* ap- 

 pears, as we have said, to be prolonged southwards nearly to 

 the source of the Soar; and in the direction of Lutterworth it 

 must be overlaid by such a mass of new red sandstone and 

 lias that we can entertain little hope of reaching the coal 

 within any workable depth in that quarter. 



But on the west of this anticlinal line we find the Warwick- 

 shire coal-field, ranging by Atherstone and Nuneaton : this is 

 bounded on the east by a transition chain of grauwacke and 

 quartz rock traversed by beds and dykes of trap rocks*. This 

 coal-field is worked from near Coventry on the south, almost 

 as far as Tamworth to the north. 



In Mr. Yates's account referred to in the note, it is said to 

 be bounded on the west by a limestone ranging from Bed- 

 worth by Arbury to Annesley ; but no description of its cha- 

 racter or relative position is given which can enable us to 

 judge whether it is magnesian lime resting on the coal, or 

 an older lime supporting it. As it is said at Bed worth and 

 Arbury to dip west, conformably to the coal, we should na- 

 turally conclude it to be the magnesian superstratum; but as 

 at Annesley it is said to have an opposite dip, it may possibly 

 be an older rock abutting against the coal by a fault. This 

 point should be carefully investigated, because on its solu- 

 tion depends the problem, whether the coal of this field is 



• In inv ' Outlines ' a hasty glance had induced nic to mistake the quartz 

 for a variet) of millstone grit, and the grauwacke' lor coal shale; lint I am 

 li.'i;>|i\ io declare my assent to the correction of my errors by Mr. Yates, 

 Geol. Trana Nf.S. vol, ii. p, 261. 



2 Y 2 



