169 



THE CONGLOMERATES UNDERLYING 



THE CARBONIFEROUS LIMESTONE IN THE N.W. 



OF ENGLAND. 



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



(^Continued from page S). 



The following comparison of sections is given to make 

 the relationship clearer. Where a gap is left the exposure 

 is obscured : — 



Micklegill Beck. Chapel Beck. 



Dun coloured limestone Dun coloured limestone 



Dark brown mudstone Dark brown mudstone ... 



Light green conglomerate 



Bluish green shale Bluish green shale 



o o 



o o 

 ^^ 



CT) en 



,^ ,, . , , , r Light yellowish sandstones, 



\ellowish green sandstone I ^ .^ ^^^ ^,.^^. .^^^^) 



pebbly m places | ^^^^^^^ ^^^^^ g,^^,^ 



T-, , , ^ f Red flaky sandstone 



Red sandstone \ Red sandstone 



Red conglomerate Red conglomerate 



Red sandstone Red sandstone Thickness 



variable. 



From the close similarity of the two sections and the perfect 

 agreement in dips of the different beds, the passage from the 

 red series in these becks into the green series and onwards 

 into the limestone appears to be a perfectly conformable one. 



(2) — BiRK Beck^ Stakeley Beck, Etc. 



In this area the exposures are interesting, but the inter- 

 pretation of the field evidence is difhcult and the present 

 interpretation is merely a temporary working suggestion. 

 It is quite possible that it may require alteration as more 

 field w(>rk is done. 



{a) Birk Beck. Commencing at the village of Green 

 holme, about a mile north-west of Tebaj', and going up Birk 

 Beck, a tributary of the Lune, joining the latter at Tcbay, 

 the following series of beds is passed over. First of all, just 

 where the small stream, Eskew Beck, joins Birk Beck at 

 Greenholme, and also in the bed of Birk Beck itself above 

 the village, the Silurian rocks are well exposed, dipping ver\ 

 steeply ; and 300 yards above the village in Birk Beck the 

 junction between these Silurian rocks and the overlying 

 conglomerates is displayed. Downstream the old rocks can 

 be seen dipping quite steeply, and on the eastern bank of the 

 stream, overlying these older rocks, is an exposure of red con- 

 glomerate fairly coarse in texture, pebbles 4 in. to 5 in. across 

 forming a small cliff about 15 feet high, but giving little 

 indication of dip. These red conglomerates form the bed of 



1921 May 1 



M 



