Rev. J. F. Blake — The Llanheris TTnconformity . 223 



the slates are above the conglomerate. According; to my reading, 

 the conglomerate is unconformable over them. Tliat is, the slates 

 are helow the conglomerate. Here, then, is a clear issue. As to 

 this, my opponents state as "further proof" of their view, that "the 

 grits continue the succession above the conglomerate," and " rain- 

 spot breccia [i.e. rock like the underlying breccia at Green's section] 

 recurs above the supposed unconformity." Now, if the authors 

 could point to any clear section in which a rock undoubtedly 

 belonging to the banded-slate series, whether a grit, a breccia, or 

 a slate, can be seen overlying Green's conglomerate in regular 

 sequence, it would be fatal to my accounjt of the rocks. This ought 

 not to be a difficult matter, somewhere along the line of junction 

 depicted on their map, but they do not point to any such section ; 

 they use the ambiguous phrase " continue the succession." If they 

 cannot do so, but only assume that the " grit " and " rain-spot 

 breccia," from their position to the north-west, i.e. in the direction 

 of the supposed dip, of the conglomerate, must lie above it, the 

 circularity of their " proof " leaves nothing to be desired. 



On the other hand, I have searched in vain for such a section, but 

 have only found patches of conglomerate overlying slates, as figured 

 by Professor Green, not only immediately above his section but also 

 to the north-west of it. The ground about here, however, is low 

 and hummocky, and does not yield good sections. Further up the 

 hill it is more hopeful. Above the Fachwen road the junction runs 

 obliquely up the hill, making a large angle with its former direction. 

 According to my opponents' explanation, it is the lower beds here 

 that form the higher ground, which they account for by giving the 

 synclinal axis a dip towards the lake.^ Along the line of junction 

 here there are some clear sections which are so fatal to my critics' 

 views that I am sure Miss Raisin cannot have seen them, as she 

 could never have suppressed them if she had, especially as I alluded 

 to them in my former paper. They are shown in Fig. 7. They are 

 found a little to the north-east of the spot where I marked + on my 

 map. The first is near to the angle of a wall, where it curves round 

 as shown on the 6 inch ordnance map. They cannot be missed, and 

 they speak for themselves. The drawings represent nearly vertical 

 faces, and the sides of the crags show that the conglomerate is not 

 carried down behind the slate. The underlying slates are continuous 

 as far as can be seen down to the tramway, and the conglomerate is 

 of the same type as all three in that section. Other similar sections 

 continue the line till we are removed only by a narrow valley from 

 the continuation of the conglomerate adjoining the. felsite, the only 

 visible rock intervening being a boss of greenstone. I claim that 

 the test proves my reading to be right.^ 



^ They do not explain how they get the synclinal down again into the furthei' 

 valley consistently with their mapping of the beds ; nor do they account for the 

 enormous expansion of the strata between the conglomerate and slate compared 

 with the tramway. T Bigl summit is also represented as on slates, and not on 

 laminated grits, but this may be an uniutentional error. 



2 It is also in accordance with Sir A. Ramsay's section. 



