Vol. 54.] RAILWAY BETWEEN LINCOLN AND CHESTERFIELD. 



161 



limestone with intervening marls. The basement-breccia, which 

 occurs farther south, does not appear to be present here ; at least it 

 is not recorded in the shafts of the tunnel illustrated in PI. X 

 (vertical sections). The Lower Limestone is by far the most im- 

 portant division, the Middle Marls being merely a thin stratum, 

 while the Upper Limestone is represented only by the thin flaggy 

 limestone seen near Parson's Wood. 



At Langwith Junction there are deep cuttings in the Magnesian 

 Limestone, both along the main line and in the Clown branch, as 

 weU as in the Midland Railway below, which well show the false- 

 bedded character of the rock and how much it obscures the true dip 

 of the beds. About | mile from the station, opposite Upper Lang- 

 with, there is a well-marked anticlinal axis, at which the dip of 

 the beds turns over to the west, and about | mile beyond this, at the 

 last bridge in the cuttiag, the limestone is cutoff by a fault running 

 in a north-westerly direction, which brings down the red sandy 

 marl on the west side. This section, which is just on the steep 

 side of the valley, is interesting from there being about 5 feet of 

 rubble in the upper part, which has slipped down when the hill 

 was higher, and distinctly turned over the edges of the surface-beds 

 of marl. 



The line now follows the valley of the River Poiilter for about a 

 mile, there being no sections till the deep cuttings in the Magnesian 

 Limestone near Scarcliff are reached, where the beds dip from 2° 

 to 5^, and in some cases as much as 10° to the east. The false- 

 bedding is here very marked, the upper part of the cutting being 

 in some places quite unconformable to that below, and dipping at a 

 high angle in the opposite direction. 



Pig. 2. — Section in /Scarcliff cutting, showing marked, false-hedcling, 

 amounting to unconformity, in the limestone. 



[Height of section = about 30 feet.] 



Between Scarcliff and Bolsover the line crosses the Permian 

 escarpment by a tunnel nearly 1| mile in length, the shafts of 

 which afford a good insight into the thickness of the beds. (See 

 PI. X, vertical sections.) 



The maximum thickness of the Magnesian Limestone met with 

 in the shafts was 61 feet; but this is probably not nearly the full 

 thickness of that formation, a considerable amount of the upper 

 beds having been denuded away. The lower part of the shafts, and 



