488 



ME. F. EUTLEY Otf THE EOCKS 



Again, we must remember that cleavage- and other superinduced 

 structural planes do not bound any marked differences in texture or, 

 more especially, in mineral constitution, unless they agree with 

 planes of stratification ; and this appears to be a matter worth some 

 consideration, for, if foliation invariably agree with planes which 

 are not planes of stratification or lamination, we have to account 

 for the very marked differences in texture and often in mineral 

 constitution which are frequently met with in metamorphic rocks, 

 and which certainly simulate, even if they do not actually represent, 

 bedding. In a district such as the Malverns it is most easy to be 

 led astray by appearances, and amid the many tempting possibilities 

 which present themselves a wrong one may be chosen. It may be 

 that I have done so in treating these gneissic and schistose bands 

 as stratified beds of rock ; but, if so, the error begins and ends with 

 the treatment ; for although I am inclined to believe that the 

 divisional planes, with which the foliation appears to be parallel, 

 may be planes of original stratification, and, although I have based 

 the accompanying section upon such a possibility, I regard these 

 planes for the present merely as structural jolanes of some sort, 

 between which the rocks exhibit divers lithological characters *. 



Note to accompany the Plans and Section. 



For the sake of clearness two plans are given in juxtaposition, on 

 one of which, fig. 2, only the faults are shown. Those given on 

 Dr. Hell's map are represented by continuous thick lines, while my 

 own extensions of them are indicated by dotted lines. The outcrops 

 of the Upper Llandovery beds and the Woolhope limestone on the 

 western flank of the range serve to show the direction of the dis- 

 placements produced by some of these faults. 



On the other plan, fig. 1, strikes and dips as well as faults are 

 represented, those strikes recorded by Dr. Holl being shown by 

 continuous strokes, while those which I have added from observa- 

 tions made on the ground are denoted by dotted lines. The 

 accompanying section (fig. 3) must be regarded as more or less dia- 

 grammatic, its purpose being to illustrate the views put forward in 

 this paper concerning the general structure of the range. 



To render the section less confused, the trap-dykes and the 

 numerous granite or pegmatite veins which have been described 

 are omitted, since although there is abundant evidence that some of 

 them are intrusive, it seems by no means certain that many of 

 those which follow the general strike of the beds do not actually 

 belong to the gneissic series in w 7 hich they occur. 



* During the completion of the first part of this paper, in which the work 

 of Dr. Harvey B. Holl is so frequently cited, came the sad intelligence that 

 that skilled geologist had been taken from our ranks. 



He leaves to us in his writings a lasting memorial of conscientious research. 



