Yol. 56.] GEOLOGY OF THE MALVERN AND ABBERLEY HILLS. 145 



summer Hills. The Silurian rocks west of the Herefordshire Beacon 

 show no evidence of marginal conditions, such as we might expect 

 if the various strata overlapped against a steep shore in the manner 

 suggested by Holl. 1 It is probable, therefore, that the close asso- 

 ciation of May Hill Beds with the Archaean of the Herefordshire 

 Beacon is due to movements subsequent to the deposition of the 

 Silurian Series. This is in harmony with the view already ex- 

 pressed, that the Archaean of the Herefordshire Beacon has been 

 thrust on to the Silurian ; moreover, evidence will be given later 

 (p. 160) tending to show that the May Hill Beds of the Northern 

 Malverns have not been deposited directly upon the Archaean. 



A more or less extensive covering of May Hill Beds might con- 

 ceivably have been given to the Malvernian Series of the Beacon Hill 

 by deep infolding accompanied by overthrust of the Warren House 

 Rocks, the sandstone in that case representing the attenuated middle 

 part of a fold. Against this view must be set the circumstance 

 that pieces of the sandstone are far from common along the line of 

 junction between the Malvernian and Uriconian Series. From the 

 analogy of other districts in the Range the more probable explana- 

 tion would seem to be that the May Hill Beds are present in the 

 form of slips embedded in the Malvernian massif, like those 

 of the Southern Malverns, Malvern Tunnel, and North Hill (see 

 pp. 147, 149, 151), such slips marking the remnant of an infold ; 

 as such they are represented in figs. 2 & 3, p. 141. 



It is certainly remarkable, on this hypothesis, that no traces of 

 rocks other than the May Hill Sandstone occur abundantly on the 

 Beacon. I have sought diligently for fragments of the Cambrian 

 Quartzite or Hollybush Sandstone on the hill, but without success. 

 Further exposures and detailed mapping of the Archaean Series on 

 a large scale may hereafter throw light on this question, and 

 possibly may establish the existence of one or more thrust-planes 

 traversing the Archaean massif itself. 



IV. The Depression between the Herefordshire Beacon and 



Black Hill. 



This deep hollow is evidently marked by one or more lines 

 of faulting, for the schists of the two hills differ markedly in strike 

 (see Map, PI. YIII). One of these faults was recognized by Holl, 5 

 and again by Mr. Kutley. 3 Prof. Hughes also speaks of ' a system 

 of faults running through by Wind's Point.' 4 One of these, running 

 along a deep depression, appears to bring the Uriconian of Tinker's 

 Hill against the Malvernian of Black Hill. Two more faults, the 

 precise location of which is difficult, seem necessary to explain the 

 presence of a mass of May Hill Sandstone occupying the western 

 portion of the hollow. This patch is shown in Phillips's sketch- 



1 Quart. Journ. Geol. Soc. vol. xxi (1865) p. 100. 2 Ibid. p. 96. 



3 Ibid. vol. xliii (1887) p. 486. 4 Ibid. vol. liv (1898) p. 563. 



Q.J.G.S. No. 221. L 



