THE CONGLOMERATES UNDERLYING 



THE CARBONIFEROUS LIMESTONE IN THE N.W. 



OF ENGLAND. 



J. A. BUTTERFIELD, M.SC, F.G.S. 



( Continued from The Naturalist for ig20, page 284). 



II. — The Tebay Area. 



In a previous paper,* the distribution of the above con- 

 glomerates (long known as the Basement Conglomerates) 

 in the Sedbergh Area was outlined, in a general way, and it 

 was stated that in Nor Gill, near Sedbergh, there appeared to 

 be evidence of a transition from the coarse red conglomerates 

 into the Lower Limestone Shales. It is intended to give here 

 a similar account of the general distribution round Tebay, and 

 much clearer evidence of that transition. In the Sedbergh 

 area the deposits consist of red conglomerates mainly, with a 

 few interbedded red sandstones ; but in the area under con- 

 sideration there is a very different constitution, the red sand- 

 stones covering a much larger area than the red conglomerates, 

 and a series of light green conglomerates and sandstones 

 appearing which are quite absent in the Sedbergh area. Prob- 

 ably none of the deposits at Tebay are so old as the coarse 

 red conglomerates of the bed of the Rawthey at Sedbergh. 



The area is contained in the three Ordnance Survey 

 •quarter sheets (6 in. to mile), numbers 21 S.E., 28 N.E., and 

 20 N.W. The accompanying sketch map gives a general 

 idea 01 the geological features, though, for the sake of clearness, 

 all deposits of alluvium have been left off. The writer m.ust 

 accept sole responsibility for the ideas contained in it, and it 

 is quite possible that it may require considerable amendment 

 as more field work is done. Reference should also be made 

 to the one-inch geological map of the district. 



From the one-inch map it will be seen that near to Penrith 

 the conglomerates occupy a fairly large area around the 

 Mell Fells, f but from the south-east corner of this area south- 

 ward there is only a very narrow strip, varying in width up 

 to about lialf-a-mile, which skirts the outcrop of the Carboni- 

 ferous Limestone in the form of a crescent, curving round 

 eastwards for a short distance when it reaches Tebay. The 

 portion contained in the sketch-map is the southern portion 

 of this curve, extending about three miles east and three miles 

 north-west of Tebaj^ village. This narrow strip of conglomer- 



* See Tlie Natitvc^list, August, 1920, p. 249, and Sept., 1920, p. 281. 

 t ' Mell Fell Conglomerate,' Green. Proc. Geol. Assoc, Vol. XXIX., 

 p. 117. 



1921 Jan. 1 



