1893.] evidence for the Recurrence of Ice Ages. 115 



xiv. Scr'atched boulders in and Striated floors below the Basement 

 Beds of the Carboniferous System. 



The case of the conglomerate at the base of the Carboniferous 

 System is much more clear and, as near as may be, gives us an 

 opportunity of proving the negative. 



The E,ev. J. G. Gumming^ remarked that the Old Red Gon- 

 glomerate (by which he meant what is now often spoken of as 

 the Basement Bed of the Garboniferous) looked " extremely like 

 a consolidated ancient boulder clay formation " and suggested 

 that the scaly fish " had to endure the buffeting of icy waves," 

 and in an article ^ upon the Geology of Cumberland and West- 

 inorland he extended these remarks to the Old Red Conglomerate 

 of the Lake District. 



Professor Ramsay'' advocated the view that these conglomerates 

 were of glacial origin, founding his opinion upon the following 

 observations : (1) the manner of their occurrence in isolated 

 patches in old valleys ; (2) the character of the deposit which is 

 a coarse conglomerate, showing a very irregular accumulation ; 

 (3) the shape of the included fragments which is very similar to 

 that of the fragments of the same formations in the glacial drift ; 

 and, (4) the occurrence of scratched stones. Upon this I ventured 

 in 1867 to offer the following remarks'*: "But we must remember 

 that any subaerial or fluviatile deposit, covered by an encroaching 

 sea, must have that patchy character, that in its irregular accumu- 

 lation, and the shape of the stones, it more resembles the gravel 

 drift of the valleys than the Boulder Clay ; and the origin of this 

 gravel drift is, at any rate, doubtfully glacial. I think we must 

 be cautious, too, about referring the scratches on the stones to 

 glacial action — though undoubtedly they are like those found in 

 the true drift, and the shape of the stones is also the same. Yet 

 they have never been found except where we have other evidence 

 that the beds have been much disturbed. We see, where the red 

 conglomerate can be examined close to great faults, that the beds 

 do not get crumpled up, as in the Silurian or any even bedded 

 homogeneous rocks, but that, because the hard and included 

 pebbles resist more than the soft matrix, the whole mass readjusts 

 itself to suit its new position, the included pebbles being often 

 scrunched against one another, scratched, and broken. 



" In one place I found, inclined at a small angle to the bedding, 

 a face of jointage, on which were striae similar to those on the 



1 Hist. Isle of Man, 1848, p. 89. 



^ History and Topography of the Counties of Cumberland and Westmorland. By 

 W. Whellan. Pontefract, 1860, p. 28. 



3 Q. J. G. S., Vol. XI., 1855, p. 187. The Reader, Vol. vi., Aug. 12, 1865, p. 186. 



* Notes on the Geology of parts of Yorkshire and Westmorland. Geol. Polyteeh. 

 Soc. W. Eiding, Yorkshire, July 17, 1867. 



9—2 



