30 THE GEOLOGY OF THE OLD RADNOR DISTRICT. [vol. lxxiv, 



of any igneous intrusions in the Old Radnor Inlier. The abundance 

 of algal remains in the Woolhope Limestone Avas a revelation, and 

 he had been greatly impressed by the important })art played by 

 these organisms as rock- builders. He congratulated the Authors 

 upon the valuable work which they had done in a district that had 

 been too long neglected. 



Dr. A. H. Cox remarked on the great interest with which he 

 had listened to the paper, in view of certain resemblances between 

 the district under discussion and the Pedwardine or Brampton - 

 Bryan district, some 10 miles north-east of Old Radnor, an area 

 that he himself had investigated a few years previously. He had 

 then suggested that the Brampton-Bryan rocks were of Long- 

 myndian age, and that the}' belonged to the ' Bayston Group ' of 

 Prof. Lapworth. This view gained additional support from the 

 fact, now established as the result of the Authors' examination 

 of Old Radnor, that there also the rocks were Longmyndian, and 

 still further, that they were to be referred to the Bayston Group. 

 While working at Brampton Bryan the speaker had paid a brief 

 visit to Old Radnor, and he concluded that the Old Radnor rocks 

 were Longmyndian, but, if anything, a little lower than the con- 

 glomerates of Brampton Bryan. Now the Authors had discovered 

 at Old Radnor conglomerates that matched in every respect the 

 conglomerates of Brampton Bryan, and of Stanbach in the main 

 Longmynd area. There appeared, consequently, to be little room 

 for doubt that the correlation of the rocks of the three areas was 

 correct. The speaker had further suggested that at Brampton Bryan 

 the Longnryndian had been thrust eastwards horizontally over Cam- 

 brian. He was accordingly very pleased to see actual photographs 

 from Old Radnor showing Pre- Cambrian rocks thrust horizontally 

 over Silurian, giving more definite information as to the age of the 

 movements than was to be obtained at Brampton Bryan. It was 

 extremely fortunate that the investigation of the alga? had led the 

 Authors to the examination of a district that yielded such good 

 results. 



Prof. G. A. J. Cole enquired as to the general strike of the 

 Longmyndian rocks of Old Radnor, which seemed, by the trend of 

 the conglomeratic bands, to be northward on the whole. The north- 

 easterly and south-westerly direction of the axis of the mass, as 

 now exposed, appeared to be due to the cutting-up of the district 

 by the faulting. 



Prof. E. J. Garwood, on behalf of the Authors, thanked those 

 who had taken part in the discussion for their appreciative remarks. 

 In reply to Prof. Cole, he said that the strike of the Archaean rocks, 

 so far as the individual beds were concerned, was difficult to trace 

 for more than a short distance — the direction of the longer axis of 

 the inlier and the trend of the boundary-faults were in a general 

 north-easterly direction : that was, in a line with the Caledonian 

 trend of the Longmynd range. The Nash-Scar Limestone, 

 described in the paper, was shown to be identical with the algal 

 development at Old Radnor. 



