562 MK. H. D. ACLAND ON A VOLCANIC 8EKIES [Aug. 1898^ 



definite opinion, I have already directed attention to the similarity 

 betvt^een this specimen and another from Tinker's Hill (283): 

 they are practically on the same strike, and I have described very 

 shortly their characteristics. There is, however, a great develop- 

 ment of epidote in this specimen, which is interesting when I call 

 attention to the other rock that I wish to notice (179). This comes 

 also from the southern flank of Hangman's Hill, within a few feet 

 of 180. The rock is greenish grey with red spots, and very hard 

 ( + 7 in Mohs's scale). Under the microscope it appears to be a 

 highly altered felsite. Mr. Harker, in his * Petrology' (p. 143), 

 suggests that some of the rocks from the Reservoir may throw light 

 on the origin of epidosites. Now this rock appears to be a true 

 epidosite. The exposure is very small. 



I need hardly refer to the rocks in the neighbourhood of Clutter's 

 Cave : Mr. Rutley has described them very fully.^ What their 

 relation is to those shown by the Reservoir-excavation cannot at 

 present be determined, beyond the fact that a similar rock appears 

 in the series there. They are described by Mr. Rutley as basalts. 

 I have failed to find any of the more acid rocks west of Clutter's^ 

 Cave. 



Prom the foregoing pages it may be inferred that a very interesting 

 series of rocks is to be found in this limited area. Their age is not 

 easy of determination : they may be, as Dr. Callaway has said in his 

 paper,^ of a very different period from the rocks of the main axis of 

 the hills. It is evident, from the bosses of igneous rock that occur 

 farther south in the Hollybush Sandstone, that some form of 

 energy was being exerted at a much later date than the consolidation 

 of the Malvern Hills. Whether these Reservoir rocks have any 

 relation to a lost centre of volcanic activity in the neighbourhood 

 must remain, for the present at least, a matter of conjecture. 



I desire in conclusion to make my best acknowledgments to the 

 late Prof. Green, Prof. Bonney, Prof. T. McK. Hughes, Mr. Rutley, 

 Miss Raisin, Dr. Callaway, and Mr. H. H. Arnold-Bemrose, who 

 have so kindly placed at my disposal the stores of their greater 

 knowledge and experience. 



Discussion. 



Dr. Callaway called attention to the resemblance between these 

 volcanic rocks and the Uriconian Series of Shropshire, in which all 

 the principal types were represented. 



Prof. Hughes thought that the beds- described by the Author 

 belonged to the Bangor Series — that is, to the volcanic beds which 

 in the Bangor area rest upon the massive rhyolites. Those lower 

 rhyolites, which he had distinguished under the name Dinorwig 

 Series, were not, he thought, represented in the Malvern reservoir- 

 section. These two series together constituted Dr. Hicks's original 

 Pebidian. The geological structure of the district he explained by 



1 Quart. Journ. Geol. See. vol. xliii (1887) p. 497. 



2 75,-^ ^oi 3^j^ (1880; p. 536 



