part 1] ON THE GEOLOttY OF THE OLD RADNOB DISTEICT. 11 



Shropshire, has separated the Western Longmyndian, or Wentnpi* 

 Series, from the Eastern Longmyndian or Stretton Series, and has 

 further subdivided the Wentnor Series into two sub-groups, the 

 Ratlinghope Group and the Bayston (J roup. The latter of these 

 two groups is well displayed near Bayston Hill, and also on Lyth 

 Hill. It consists of red and grey grits with the three zonal 

 conglomerates of Stanbach, Darnford, and Haughmond, the last- 

 mentioned being rich in pebbles of volcanic rocks. 1 



During the progress of our work in the Old Radnor district an 

 opportunity occurred of discussing with Prof. Lapworth the pro- 

 bable position of the Old Radnor series in the Longmynd sequence, 

 and also of examining the typical Shropshire exposures under his 

 personal guidance, and we owe to him the suggestion that the Old 

 Radnor rocks might well represent some portion of his Bayston 

 Group. Further detailed investigation of the rocks of the district 

 has only served to conrirm his conclusion that the Old Radnor 

 series represents the southern continuation of the Bayston Group. 

 The southernmost outcrop of this group, in the Longmynd range, 

 occurs near Asterton, but Dr. A. H. Cox has recently given 

 reasons for including the grits and pebble-beds exposed between 

 Brampton Bryan and Pedwardine, some 12 miles south of Asterton, 

 in the Longmyndian 2 ; and Prof. Lapworth has called attention to 

 the resemblance of these beds to the Stanbach Conglomerates of 

 the Bayston Group. 



We have examined the outcrop of these beds displayed in 

 Brampton-Bryan Park, and have been impressed by their resem- 

 blance to the grey conglomerates and grits of the Old Radnor 

 series. The two districts lie only some 9 miles apart, and, in both, 

 the rocks have a definite north-eastward trend ; their apparent dip 

 also, in both cases, is about 70° in a general westerlv direction. 



If we compare in detail the Old Radnor series with the typical 

 Bayston Beds of Yat Hill, the close resemblance between the two 

 is strikingly apparent. Practically every type of rock that is- 

 characteristic of the series on Lyth Hill is represented at Old 

 Radnor. The conglomerates of Old Radnor resemble very closely 

 the Stanbach and Darnford Conglomerates of Lyth Hill, the former- 

 showing abundant fragments of grey and pink quartz, the latter 

 haA'ing a preponderating red tint and innumerable fragments of 

 pink quartzites and red rhyolites. Even the double character of the 

 Darnford rock is duplicated in the outcrop of pink conglomerate 

 west of Old Radnor Church, while the various shades of pink, 

 green, and buff-coloured grits and greywackes may be closely 

 matched in the two series ; even the bright crimson bands so 

 conspicuous on the path leading from Lyth Hill to Windmill Hill 

 are represented at Old Radnor by similar streaks of fine mudstone 



1 C. Lapworth & W. W. Watts. ' Shropshire ' in 'Geology in the Field" 1910- 

 (Jubilee vol. Geol. Assoc.) chapt. xxx. p. 748. 



2 ' On the Inker of Longmyndian <fc Cambrian Rocks at Pedwardine (Here- 

 fordshire) ' Q. J. G. S. vol. lxviii (1912) p. 364. 



