4-03 



been elevated to a considerable height, and subsequently denudated 

 by the operation of water, as observed by Dr. Richardson, in Ids re- 

 marks upon the basaltic counties of Antrim and Derry in Ireland. 



It is to these tracts of elevated strata, and their abrupt termina- 

 tions, or faults, in the county of Derby, that the author's observations 

 have been principally directed ; and he enumerates a series of four 

 different elevations, in succession, one within the other, of which the 

 innermost is most elevated. The outermost, or least elevated, ex- 

 tends from Nottingham northward into Yorkshire, as far as the river 

 Wharf, this being the eastern boundary of the tract ; while its western 

 boundary extends from near Stone, in Staffordshire, to the neigh- 

 bourhood of Manchester. On the south it is bounded by a fault, 

 which the author calls the great Derbyshire fault ; but its northern 

 extent has not yet been ascertained by actual observation. 



The second tract, which is much more elevated than the preceding, 

 is separated from it by a fault, which, from the irregularity of its 

 course, is termed the zigzag fault. The elevation of this second tract, 

 on its southern extremity, is such as to bring the great limestone 

 shale, which underlies all the coal strata, against the red marl at 

 the surface. 



The third inner tract is considered by the author as still 400 yards 

 more elevated than the second ; so that the fourth or lowest limestone 

 rock is raised into a high hill, with red marl at the foot of it, on the 

 other side of the great Derbyshire fault, which here occasions a de- 

 rangement far exceeding anything that has hitherto been conceived 

 to exist. 



Of these tracts the outermost appears to have but little inclination 

 to the horizon ; but the second and third are inclined to each other, 

 and to the adjacent strata, in a direction from S.W. to N.E., the 

 mutual intersection of the strata, or hinge on which they may be sup- 

 posed to turn, passing from Cromford in a north-westerly direction. 



The fourth tract includes Bakewell, and a small district round it, 

 and is surrounded by a fault, which Mr. Farey denominates the Bake- 

 well fault. The western side of this tract is most elevated, as well 

 as that of the third, so as to occasion a great elevation of some strata 

 of toadstone, in situations where their appearance had not before 

 been explained. It is in this district that, in Mr. Farcy's estimation, 

 the lowest strata anywhere observable in Britain appear. He reckons 

 as many as three distinct series of coal measures, separated by thick 

 strata of limestone, and of red marl, similar to that which intervenes 

 between the lias and the uppermost stratum of coal ; and the lowest 

 of the coal measures is that of the coal-field of Derbyshire, Notting- 

 hamshire, and Yorkshire, lying beneath the yellow limestone rock. 

 Beneath these follows what is called the fourth limestone rock, which 

 extends from Castleton, in Derbyshire, southward to Weaver-hills, 

 near Wootton and Ramsor in Staffordshire. This he supposes to be 

 the lowest of all British strata ; and to this circumstance ascribes the 

 occurrence of some phenomena, which are said to appear nowhere 

 else. 



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