part 3] silurian rocks of the clun-forest district. 237 



the succession is fairly clear ; the thickness of the various beds, 

 however, can only be measured approximately. 



The road from Weston to Bucknell Station, and along the 

 adjoining railway. — About 320 yards east of the house marked 

 Cubach on the 6-inch Ordnance Surve}^ map, 1 beds are exposed on 

 the side of the road, and in the railway-cutting adjoining, which 

 have yielded Chonetes striatella, Orthis lunata, and Rhynchonelht 

 nucula, and are evidently typical Chonetes Beds. A short distance 

 farther east along the road, and also in the lane to the north-east, 

 are the greenish laminated mudstones previously mentioned as 

 t} T pical of the Upper Chonetes Beds (p. 230). From them Spirifera 

 elevata has been obtained. These beds may be followed in the 

 shallow^ gutter at the side of the road and about 45 } 7 ards west of 

 the gate to the cart-track through the wood to the north, they give 

 place to the greyish Platyschisma Shales, which form the base of 

 the Temeside Group. These shales are not very distinctive in 

 character, and they pass gradually through greenish shales into a 

 thinly -bedded, } T ellow, micaceous sandstone, succeeded h\ massive 

 yellow sandstone about 5 feet thick. This sandstone, in all 

 respects identical with the Downton-Castle Sandstone in the type 

 district, crops out in a small roadside quarry near the edge of the 

 wood. In its upper portion the sandstone is more greenish and 

 laminated. It is succeeded abruptly by rubbly green Temeside 

 Shales, exposed also in a small quarry on the south side of the road. 

 The calculated thickness of the Downton-Castle Sandstone Series 

 from the base of the micaceous shales is about 110 feet, and of this 

 the sandstone proper occupies only the upper 10 feet. Throughout 

 the section the dip is steep (in the small quarries it amounts to 

 about 30°). Although no beds higher than the rubbly green marls 

 can be seen, there is hereabouts a marked change of colour in the 

 soil from brown to red, and this can be distinctly traced through 

 the fields to the north. About 400 yards farther east, immediately 

 below the bridge over the railway, a small river-cliff reveals the 

 presence of very micaceous green grit and hard, compact, green rock. 

 No evidence has been noted of purplish sandstone or of other rocks 

 that could be definitely assigned to higher beds than the Temeside 

 Shales ; hence it is probable that Temeside Shales occup}' the whole 

 of the low ground around Bucknell eastwards to the great fault. 



A succession very similar to the above can be traced on the hill- 

 slope north-west of Bucknell village. 



(2) Five Turnings Outlier. 



(a) Old Quarry 300 yards east of Black Garn Farm.— In the 

 valley below the quarry greenish Upper Chonetes Beds crop out. 

 Succeeding these beds are Platyschisma Shales, of the dark mica- 

 ceous type seen in the quarry above. Linguhi minima is abundant 

 in the lower part of the quarry, while in the upper part are bands 



1 Shropshire 76 S.E. 

 Q. J. G. S. No. 295. T 



