512 Percy F. Kendall — Brockrains of Vale of Eden. 



vein quartz in a quartzite matrix, and finally pebbles of rbyolite. 

 At other exposures to the northward at Flakebridge the same 

 characters recur. 



The source of the different pebbles may now be considered. The 

 limestones are of course fi-om the lower part of the Carboniferous 

 Series ; they present peculiar features. The pebbles of vein quartz 

 are clearly derived from the numerous quartz veins in the Skiddaw 

 Slate of the Cross Fell inlier, but their thoroughly rounded condition 

 shows that they must have come at an intermediate stage through 

 some pre-Permian conglomerate. This conclusion is confirmed by 

 the occurrence of fragments of conglomerate containing such pebbles, 

 which is recognizable as the very characteristic Basement Carboni- 

 ferous Conglomerate of the Cross Fell Eange. 



The angular blocks of quartzite can be matched precisely by the 

 rocks which succeed the Basement Conglomerate of Roman Fell. 

 The author at one time regarded the rhyolites as indisputable 

 evidence of the exposure of the Borrowdale rocks of the Cross Fell 

 inlier and denudation during Permian times, but while this still 

 seems to be the most pi'obable explanation of their presence in the 

 Upper Brockram it is possible that they could have been derived 

 from the Carboniferous Basement Conglomerate, in which at Swindale 

 Beck a few such pebbles occur. 



Setting aside the rhyolite pebbles, there is still a body of 

 evidence which seems to warrant deductions of very great interest. 

 The facts to be explained are the occurrence in the Lower Brockram 

 of a practically pure gathering of Carboniferous Limestone, while 

 the Upper Brockram contains a very high percentage of rocks 

 from the very base of the Carboniferous Series. They might be 

 explained on the supposition of derivation from opposite sides of 

 the Vale of Eden, the Lower Brockram being supposed to come 

 from the Carboniferous Limestone outcrop towards Orton, while 

 the Upper Brockram was derived from the Pennine Eange. This 

 view has little to commend it. If the Carboniferous Basement 

 Conglomerate were exposed to denudation during the deposition 

 of the Upper Brockram, then the Carboniferous Limestone must 

 have formed a bold escarpment at the same time ; and that being 

 granted, it is highly improbable that it failed to yield the 

 materials of the Lower Brockram, which at Hungriggs is less than 

 three miles from the outer Pennine fault which exposed a series 

 of Carboniferous rocks in Permian times. Upon the alternative, 

 and as it seems preferable, hypothesis, that the materials of the 

 two Brockrams were all derived from the Pennine Chain, an inter- 

 Permian movement of the faults which throw up the Cross Fell 

 range and the well-known inlier seems necessary. 



Professor Lapworth has pointed out that when an anticlinal fold is 

 exposed to denudation the derivative beds will consist of the same 

 material as those of the anticline, but in reverse order, the uppermost 

 beds of the anticline will yield the pebbles of the lowest of the 

 derivative beds, while the core of the anticline will be represented 

 only in the highest of the derivative beds. 



This principle may be illustrated by the Tertiary beds of the 

 south-east of England; the Lower Eocene conglomerates contain 



