24 MR. G. W. LAMPLUGH ON SOME EFFECTS OF [Feb. I9OO, 



to the ordinary cyclonic movements of the air in the northern 

 hemisphere. These knoll-reefs of Mr. Marr (as well as the Poolvash 

 thrust-planes), like the ' klippen ' of the Yale of Eden, come into 

 the proper position for overfolding and overthrusting. The exquisite 

 preservation of the knoll-reef fossils is due to the fact that these 

 4 reefs ' are ' augen ' on a gigantic scale, where pressure has been 

 locally relieved and the fossils preserved in infiltrated carbonate of 

 lime. 



It is by no means unlikely that the knoll-reefs and the Isle- 

 of-Man phenomena, as pointed out by recent observers, are both of 

 the age of the 'Hercynian movement' of Suess; namely, that part 

 of the Permo-Carboniferous period which we in Britain term ' Upper 

 Coal Measures,' where igneous matter is frequent in the sediments, 

 and we have probably the intrusion of the Whin Sill, the Shropshire 

 and Midland basic rocks, etc. 



Prof. Boyd Dawktns accepted the Author's view that the over- 

 thrust- faulting was, in part at least, later than the age of the 

 intrusion of the volcanic rocks into the Carboniferous strata of the 

 south of the Isle of Man. He further remarked that the over- 

 thrust-faulting in the Bed Series of Peel, in the north-west of the 

 island, considered by the Author to be basement Carboniferous, but 

 taken by the speaker, from the included pebbles of Carboniferous 

 Limestone and Yoredale rocks, to be Permian, proves that the 

 overthrust took place after the deposition of the Permian. 



The Rev. J. F. Blake thought that the attempt to explain all 

 sorts of phenomena by ' earth-movement ' might be carried too far, 

 and some of the wilder flights of theory were in danger of sharing 

 the fate of the ' Reseau pentagonal ' of Elie de Beaumont. Such, for 

 instance, was the theory of the limestone-knolls in the Craven 

 district, which had he thought lately received its coup de grace from 

 Mr. Dakyns. With regard to the area described by the Author, if 

 it is admitted that parts of the phenomena may be those of an 

 agglomerate, there is no reason why 90 per cent, of them may 

 not be. The diagrams shown appeared to indicate supposed move- 

 ments in several convergent directions which would require explana- 

 tion ; and it seemed impossible that fragments sporadically placed 

 and angular, as drawn, could be found between two approximate 

 thrust-planes. 



Mr. Steahan remarked on the difficulty of distinguishing the 

 results of so energetic a volcanic outburst from those of subsequent 

 earth-movements. After mapping the volcanic region, both he and 

 the Author had been unable to explain some of the structures. 

 Masses of lava had been obviously broken and shifted, and there 

 were other indications of disturbance. For such phenomena the 

 Author's hypothesis seemed to offer an adequate explanation, yet 

 he could not fully accept the theory without hesitation. The 

 Carboniferous rocks of the neighbourhood showed no signs of such 

 powerful earth-movements as were claimed ; on the contrary, they 

 reposed tranquilly on the platform of older rocks near the region 

 described, and it was only in the immediate neighbourhood of the 



