Vol. 54.] SECTIONS BETWEEN LINCOLN AND CHESTERFIELD. 157 



11. Sections along the Lancashire, Derbyshikb, and East Coast 

 B.AiLWAT between Lincoln and Chester fleld. By C. Fox- 

 Strangwats, Esq., F.G.S. (Read January 5th, 1898.) 



[Communicated by permission of the Director-General of 

 H.M. Geological Survey.] 



[Plate X.] 



The portion of this railway between Lincoln and Chesterfield, which 

 has lately been opened for traffic, traverses the country in a nearly 

 east-and-west direction; and, consequently, crosses at right angles 

 to the strike all the formations from the Lias to the Coal Measures 

 in succession. At its eastern end, owing to the general flatness of 

 the country, there are not many deep cuttings ; the strata are, 

 therefore, not well exposed, and a considerable thickness of beds 

 is not seen at all. West of the Trent the ground is more hilly, 

 and cuttings are numerous ; but the finest exposures are in the 

 higher ground, along the outcrop of the Magnesian Limestone and 

 Coal Measures near Bolsover and Chesterfield, where some very 

 interesting sections occur. 



Commencing at the junction with the Great Northern E-ailway, 

 about 1^ mile west of Lincoln, the new railway crosses the level 

 ground covered by the alluvium and gravels of the little rivers Till 

 and Witham, which, according to a boring at the junction, have a 

 thickness of about 20 feet. They appear to be rather more extensive 

 than shown on the Geological Survey map, reaching about a mile 

 westward to the foot of the slightly rising ground on which 

 Skellingthorpe stands. 



At the station here about 6 feet of gravel (composed of pebbles 

 and flints) is seen resting on Liassic clay ; but the latter has not 

 been excavated, and no fossils were found to indicate to what 

 horizon in the Lias this clay belongs. At Old Hag Wood, a shallow 

 cutting shows Lias Limestone crowded with Gryphcea incurva and 

 small gasteropoda. Beyond this the Lias keeps to the surface to 

 beyond the county boundary, but does not extend so far west as 

 shown on the Survey map, being covered east of Harby Station by 

 sand with pebbles and flints. 



West of Harby the line crosses the great sandy flat which extends 

 for a distance of about 3 miles, to the foot of the rising ground near 

 Clifton. The lower part of the Lias and Rhsetic is entirely con- 

 cealed by this sand, and there is no indication Of their outcrop 

 at the point crossed by the line, the first evidence of the beds 

 beneath being at the lane about | mile east of Clifton Station, 

 where an excavation shows 3 feet of grey marls overlying red marl. 

 This section has the appearance of being at the base of the ' Tea- 

 Green Marl,' but it is a long way west of the outcrop as laid down 

 on the Geological Survey map, and without a further examination of 



