Rev. J. F. Blahe — The Llanheris Unconformity. 217 



Their occurrence indicates a long interval between the outflow of 

 the felsite and the deposit of the conglomerate, and this interval 

 must include an unconformity, since the conglomerate comes back 

 again and lies on the felsite in a very short distance. My critics 

 try to account for these numerous intervening beds, each indicating 

 some change of conditions on the same spot, by reminding us of the 

 interchangeable deposits of grit and coarser material on the seashore. 

 This I have already allowed for, having included with the con- 

 glomerate much that is only the red grit into which it passes in 

 places. 



In connection with the strata which overlie this conglomerate, 

 I am charged by my critics with inaccuracy when I say, speaking 

 of their lamination, that almost wherever seen these laminse 

 are horizontal. No doubt from its form this statement is liable 

 to be taken to mean that the strata are almost always hori- 

 zontal. That this is not the meaning might be inferred from 

 the high dips shown in my section of the railway synclinal, which 

 must necessarily be continued into the country behind. They are, 

 in fact, seen, as stated by Miss Raisin, in many places. But the 

 question is whether in places where the dips are high the lamina 

 can be seen. Possibly they can ; I have, however, seldom found 

 them, except where the strata are nearly horizontal, either in this 

 district or higher up on the hill, or on Y Bigl, and even Miss 

 Eaisin only speaks here of high dipping " outcrops," but when 

 elsewhere "lamination" is mentioned it is accompanied by the word 

 "horizontal" (loc. cit. (K), p. 588). 



These horizontal lamina are for the most part only observable on 

 the summits of elevations, such as the spots I named (10, 16, 18, 

 on my map), the last one being both the highest and best; it is 

 marked 666 on the 6 inch ordnance map. How such horizontal 

 laminae above are compatible with highly inclined outcrops below, is 

 explained by the deposit of the strata on an undulating surface. 

 Those lying in the hollows would be squeezed 'into synclinals under 

 earth pressures, being nipped in between the older and harder rocks, 

 while the higher ones might escape.^ Thus the high dipping 

 outcrops in the low ground are no arguments against the general 

 horizontality of the strata, and therefore call for little notice. If 

 Miss Raisin had given the direction of the dips she noticed we 

 might find that their average was zero. I ought to remark, however, 

 that my words " dip " and " horizontal " here have reference to the 

 apparent dip in a direction parallel to the lake-shore. There may 

 be also, and probably is, more or less of a dip towards the lake in 

 the direction of the strike of the underlying slates. 



We now pass to the strictures on my statement about the grounds 

 of Glyn Padarn. They say it is not easy to recognize my " definite 

 succession along an E.N.E. and W.S. W. line." Miss Raisin, however, 

 has succeeded in doing it and in confirming my statement. But in 

 quoting me my critics have omitted the words which I actually 



^ The manner of this was illustrated by a model at the reading of my paper. 



