162 MR. C. FOX-STRANGWArs ON SECTIONS ALONG THE [May 1 898, 



nearly the whole of the tunnel itself, is in the Coal Measures. 

 These latter are high up in the series, and it is evident that they 

 do not contain coal-seams of any value. It also appears from these 

 sections that the upper part of the Coal Measures is, at this depth, 

 not stained red by the Magnesian Limestone, as usually observed 

 aloDg the outcrop of this junction, a stainiDg which gave rise to the 

 supposition that these uppermost beds were of Permian age. 



Fig. 3. — Section at the western end of Bolsover Tunnel. 



a = Sandy shales, sloped. 



6= Sandy shales, rather harder and more sandy, vertical face. 

 c =Massive sandstone. 

 c^ = Line of fault, nearly vertical. 



e = Apparent line of fault. The semblance is probably due to b being left 

 vertical, while a is sloped. 



The western mouth of the tunnel shows a little shale over 

 massive sandstone, which a little farther on is faulted against 

 sandy shales. This fault runs in an east-and-west direction very 

 obliquely to the railway, and is nearly vertical, but may have a 

 slight hade to the north. (See fig. 3.) 



About 400 yards from the tunnel-mouth there is 5 feet of coaly 

 shale and coal dipping 2° east ; and at the station-yard an impure 

 coal-seam is seen, 3 feet thick, dipping 8° south-east. This is probably 

 the seam indicated on the Geological Survey map at Castle Lane, and 

 the highest seam shown on the Hor. Sect. Sheet 18, which is stated 

 to have been worked about 3 miles farther north. ^ 



After crossing the Doe Lea Yalley, soft rubbly and flaggy sand- 

 stones are seen at the junction with the Midland Railway ; and a 

 little farther on the deep cutting at Long Duckmanton shows sand- 

 stones and shales dipping at angles from 4° to 6° east, with a 

 seam of coal about 1 foot thick, which crops out at the bridge, with 

 another thin seam about 10 feet below this. At the summit near 

 the centre of this cutting there is an irregular bo.ss of sandstone 

 which seems to be let into a hollow in the shales, so abrupt are the 

 terminations on either side. This sudden ending-off of the Coal 

 Measure sandstones against the shales appears to occur rather 

 frequently in this district, and another instance will be noticed 

 subsequently. 



1 Expl. of Hor. Sect. Sheet 61, p. 5. 



