58 Rev. J. Clifton Ward — Geology of the Lake District. 



flattened at the sides. In some few cases these flattened sides seem 

 to bear scratches like those left by glacial action. 1 Such are the 

 chief facts with regard to this Basement Conglomerate, their possible 

 meaning will be considered directly. 



The various beds of limestone, shale, and sandstone which go to 

 form the Carboniferous framework of the district come in above this 

 very irregularly distributed conglomerate. Some of the lower beds 

 of limestone contain quartz grains and small pebbles. Generally 

 speaking, there are very frequent alternations of limestones and sand- 

 stone, with occasional shale bands and thin coal-seams. The lime- 

 stones are often highly fossiliferous and largely made up of corals. 



No volcanic ashes or lavas are found in connexion with the 

 Carboniferous rocks immediately surrounding the mountain district. 

 Lavas, basaltic in character, and often highly vesicular, occur beneath 

 the limestone all round the northern side of the framework, from 

 Cockermouth to Eycott Hill (see Sketch-Map), and could one not 

 prove by fairly conclusive evidence that they belong to the northern 

 extension of the Borrowdale Volcanic Series (on the N. side of the 

 anticlinal), they might readily be taken for Carboniferous basalts, 

 such as occur among the Carboniferous rocks in plenty upon the 

 other side of the border. 



• In one case only do igneous intrusions occur among Carboniferous 

 rocks immediately skirting the district, and that case is among the 

 basement conglomerates just east of Little Mell Fell. Four very 

 small bosses of basalt, wrapped round by hardened conglomerate, 

 and showing vesicular margins, may be seen close to Mell Fell farm. 

 That they are intrusions there can be no doubt, and microscopic 

 examination reveals their likeness to the basaltic dykes of the Pennine 

 range — a likeness which is also sufficiently evident in hand 

 specimens. 



Physical Conditions indicated. — What was the condition of our 

 present mountain tract during the great Carboniferous period ? Was 

 it wholly submerged after the elevation and denudation to which we 

 have already seen it subject, or was there always a nucleus of dry land 

 — an embryo of Cumbria — around which the Carboniferous deposits 

 were laid down ? I do not think this is a question that can ever be 

 decidedly answered. Long ago it was remarked by Prof. Sedgwick, 

 that " had our island been laid dry immediately after the Carboni- 

 ferous period, without any change of relative position among the 

 great formations, the Cumbrian mountains would have appeared as 

 a cluster of ancient rocks rising out of a great Carboniferous 

 plain." 3 That the limestone beds extended much farther than 

 their present outcrops, cannot be doubted ; but whether the elevated 

 and denuded block of Silurian strata was ever completely smothered 

 under Carboniferous deposits, may fairly be questioned. At first 

 sight one would naturally suppose that the existence of thick 

 masses of Basement Conglomerate would clearly point to shore 



1 Some such apparent ice-scratched stones from Mell Fell have been deposited in 

 the Jermyn Street Museum. 



2 Trans. Geol. Soc, second series, vol. iv. p. 47. 



