internal Structure of the Magncslan Limestone. 43 



and the external characters of the formation of magnesian hmestone. I now 

 proceed to give some account of its g-eographical distribution ; and, for this 

 purpose, I shall first trace the western boundary of the deposit from the place 

 of its commencement near Nottingham. On this subject much remains to be 

 done, notwithstanding the excellent details supplied by the geological county 

 maps of Mr. Smith. To these maps, as containing incomparably the best 

 delineation of the formation which has yet been published, I shall constantly 

 refer*. 



The magnesian rock first appears in the flat district, north-west of Nottingham, close to the 

 village of Radford. It does not cross to the south side of the canal, and it is not soon to the east 

 of the rivulet which comes down from Newstead Abbey, being, on that side, masked by diluvium 

 and hills of forest sandf. As the formation appears at a dead level, and makes no feature in the 

 district above mentioned, its boundary is difficult to trace correctly, but appears to pass a little 

 south of Aspley in a direction bearing about W. by N. to Bilborougli. Near the last. mentioned 

 place it begins to crown a distinct escarpment, near the edge of which are Strelley and Kimberley. 

 From Kimberley it ranges along the top of an eminence, and passes a little to the N.W. of 

 Watnall ; afterwards deflects considerably to the N.E. and then returns and crowns a well. 

 marked eminence a little to the east of Griesley. From thence, still preserving the same elevation, 

 it runs in an undulating line towards Annesley, south of which place a valley of denudation forms 

 a considerable bay in the outline. So far the boundary is represented by Smith, with perhaps as 

 much correctness as is possible, without a map exhibiting a better delineation of the physical 

 surface of the county. In the range through the remaining part of Nottinghamshire, the 

 demarcation is not generally pointed out by any well-defined natural feature, and has been 

 incorrectly delineated. The following memoranda will give an approximation to the true 

 boundary line. 



North of the last-mentioned denudation the limestone forms no escarpment, but appears as a 

 thin capping on an elevated ridge of the coal-measures, and does not extend quite so far to the 

 south-west as is represented in Smith's map. A similar capping of limestone stretches from 

 Annesley in a direction about north-west, and in one place crosses the road from Annesley Wood, 

 house to Alfreton. This projecting mass is carried too far by the same author; but the map is 

 so ill engraved as hardly to admit of a correct delineation. Further to the north, the limestone 

 forms the summit of an indented and lofty escarpment, not far from the edge of which stand 

 Annesley Wood-house, Kirkby Wood-house, and Kirkby. The boundary line then sweeps 

 round the south side of Kirkby, and turns along the summit of the hills to a point about two- 

 thirds of a mile west of Kirkby ; it then deflects considerably to the north-east, returns to tiie 

 north-west, and crosses the road from Sutton to Alfreton at the distance of a mile and a half from 

 the former place. fVom this point the line bears nearly due north, and crosses the road leading 

 from Sutton to the coal-field at a point not more than half a mile from the village. In this part 



* I had the assistance of Mr. Smith's county map in examining the range of the magnesian 

 limestone through Yorkshire. Geological maps of the otlicr counties through which the same 

 formation passes were not, 1 believe, published at the time the observations were made on which 

 the greatest part of this paper is founded. 



t The sand of Nottingham forest is derived from the beds of the newer red sandstone, which 

 rest immediately on the magnesian limestone. 



G 2 



