part 1] OX THE UEOLOGY OF THE OLD RADNOB DISTRICT. 23 



they were being disintegrated and incorporated in the basement- 

 beds of the Woolhope Limestone. The marked unconformity with 

 which that limestone rests upon the older rocks, sometimes on 

 grit and sometimes on conglomerate, also testifies to considerable 

 disturbance and denudation of the Pre-Cambrian rocks in Pre- 

 Silurian times. With regard to the age and direction of these older 

 movements, we have no definite evidence, as they have been obscured 

 by later disturbances. 



Post- Silurian movements. — The main lines of disturbance 

 at the present time run in a general north-easterly direction, and 

 there can be little doubt that these lines represent the south- 

 westward continuation of the dislocations which have produced the 

 characteristic scenery of the country between Church Stretton and 

 Lilleshall, brought up the old rocks at Pedwardine, and formed 

 the striking escarpment of Nash Scar. These have almost cer- 

 tainly all been produced b}^ the same set of movements, and they 

 all have a definite Caledonian trend. As in the Longmynd area, 

 the movements seem to have taken place at more than one period. 

 The latest formation affected in the Radnor district is the Old 

 Keel Sa'ndstone, so that the disturbances in this case have most 

 probably taken place in post-Devonian or post- Carboniferous 

 times. These latter dislocations appear to be in the nature of 

 rejuvenated faults which acted along lines of weakness establisheel 

 at an earlier period, as they are confined to the neighbourhood of 

 the Pre-Cambrian ridge, and do not extend into the Old Reel 

 Sandstone country on the east anel south. 



The Olel Radnor Inner is bouneleel along its eastern margin by 

 one of these main lines of dislocation which brings the Wenlock 

 Shale, in places, against the Woolhope Limestone, anel, in places, 

 against the Pre-Cambrian rocks. This faulted junction is clearly 

 exposed in Weythel Brook about 150 yards below the ford, and 

 some 300 yards south-west of the railway. Here the Wenlock 

 Shale can be seen, crushed against a smooth slickensieleel face of 

 the limestone which stanels up as a vertical wall, forming the left 

 bank of the stream. North of the railway this fault divides 

 into two branches. The more easterly branch apparently forms 

 the boundary of the inlier round the east side of Olel Radnor Hill 

 (PL II) passing close to Gore Quarry. Although this fault is no- 

 where seen, the fact that Wenlock Shale lies against the limestone 

 along the southern portion of this line anel against the Pre-Cambrian 

 farther north, precludes the possibility of a natural junction. This 

 fault is presumably the southern extension of the fault which runs 

 along the eastern flank of Nash Scar farther north-east. The 

 more westerly branch of the fault, starting near the Mission Room, 

 runs parallel to the road, a little to the west of it, as far as Yat 

 Farm, where it crosses the road and forms a distinct feature along 

 the western slope of Old Radnor Hill as far as the Olel Castle 

 mound. To the north of this, it lets down a lenticular strip of 

 limestone among the Pre-Cambrian rocks, marked by the olel 

 workings behinel the Harp Inn and Stockwell Farm. The 



