OP THE MALVEKST HILLS. 



509 



the movements which produced the upheavals, subsidences, and 

 flexures prevalent in the range. 



If the progressive development of organisms be admitted, we can 

 scarcely consider that the Trilobites found in the Cambrian rocks 

 represent the earliest forms of life, and, consequently, we may infer 

 that earlier sedimentary deposits have existed in which still lower 

 types would be found. Yet, putting Eozoon out of the question, if 

 such fossiliferous deposits exist, where are they, unless so com- 

 pletely metamorphosed that their life-history can no longer be de- 

 ciphered ? This seems an additional reason for supposing that, in 

 the Archaean rocks we have metamorphosed sediments associated 

 with the products of vulcanicity and with plutonic rocks. 



The observations embodied in this paper are necessarily very im- 

 perfect. To unravel the structure of the Malvern Hills would be 

 the work rather of a lifetime than of a few months. It should also 

 be remembered that the whole Malvern chain is only about eight 

 miles in length and barely three quarters of a mile in breadth in its 

 broadest parts ; that it is grass-covered throughout, save where 

 outcrops occur or where quarries have been opened ; and that these 

 outcrops and quarries are not sufficiently numerous to enable an 

 observer to work out the relation of the rocks to one another with 

 any precision, except in a few places. It is therefore manifest that 

 it would be unsafe to draw any general conclusions from such 

 scanty data and in so limited an area, except provisionally and with 

 great caution. 



Appendix to Paet II. 



The conclusions arrived at in this paper have necessitated some 

 alteration in the interpretation of the structure of the Malvern 

 Range, as illustrated diagrammatically in the section which was 

 appended to Part I. (facing p. 488). 



The prevalence of quartz-syenite or hornblendic granite and the 

 existence of true diorites and hornblendic gabbro indicate that, at 

 all events in a considerable portion of the North Hill, the rocks are 

 certainly eruptive. There seems also reason to believe that much of 

 the mass lying between the Dingle and the summit of the Worces- 

 tershire Beacon is also of a syenitic or granitic character, while it is 

 highly probable that the granulite occurring close to the summit 

 represents a marginal condition of the granite. Of the relation of 

 the diorite to the granite and syenite I am uncertain ; but it seems 

 probable that the diorite flanks these rocks as at Cock's Tor, Brazen 

 Tor, and other localities in Devonshire, where gabbros and sometimes 

 amphibolites rest on the flanks of the Dartmoor granite *. It is 

 probable also that, in some cases, the diorite penetrates the granitic 

 and syenitic rocks. Upon these considerations I venture to alter 

 that part of the diagrammatic section appended to Part I. which 

 lies between the northern end of the range and the Wych, as in the 

 annexed figure (fig. 4) ; but it must be remembered that this altered 



* <; The Eruptive Hocks of Brent Tor," Mem. Geol. Survey, p. 15. 



Q.J.G.S. No. 171. 2 m 



