Vol. 68.] AND CAMBRIAN INLIER AT PEDWARDINE. 365 



altitude of over 1000 feet O.D. The combined outcrops of the 

 Dictyonema Shales, and of the Brampton and Letton Beds to be 

 presently described, occupies approximate!}^ the ground between the 

 500- and 700-foot contour-lines on the eastern side of this escarp- 

 ment, forming- a strip a little over a mile long and having a 

 breadth at the widest part of rather more than half a mile. This 

 outcrop naturally breaks the symmetry of the Ludlow escarpment, 

 replacing the normal steep scarp-slope by a more gentle convex and 

 terraced slope. This merges eastwards into the wide, level, gravel- 

 covered plain occupied by the Wenlock Beds. 



II. The Brampton Grits and Conglomerates. 



The most conspicuous rocks within this strip consist of massive 

 •conglomerates and greenish grits showing no clear stratification, 

 which are exposed at several localities. The best exposure is found in 

 ^ disused quarry, in the small plantation near the entrance to Bramp- 

 ton Bryan Park. These are the beds referred to by La Touche as 

 ' Cambrian grits and pre-Cambrian rocks.' ^ Another exposure lies 

 on the Brampton Bryan-Lingen road, a third of a mile south of the 

 first-named village. 



In the park quarry the beds are seen to consist for the most part 

 of purple-green and reddish grits, which show a general tendency 

 to become conglomeratic, the pebbles being chiefly quartz with less 

 abundant felsite-fragments. These grits are not well stratified ; but 

 the bedding is shown by a few green shaly bands, which prove the 

 series to dip steeply (60° or 70°) a little north of west. There is much 

 irregular jointing, accompanied by overthrusting from the west. 



The roadside exposure mentioned above is situated some 400 

 yards east of this quarry, the two points being connected by an 

 obvious ridge. Here the dip is still less clear — owing to irregular 

 jointing, but it appears to be in the same direction as in the park. 

 The beds at this point are distinctly more conglomeratic, containing 

 pebbles up to an inch or more in diameter. Here, again, the most 

 abundant pebbles are vein-quartz of various colours, accompanied by 

 numerous ' felsite' pebbles. The majority of the pebbles are fairly 

 well rounded, a minority being distinctly angular. 



Under the microscope a specimen of the conglomeratic grit from 

 this roadside exposure shows the felsitic fragments to include 

 numerous different types of rhyolitic tuffs and rhyolites. Among 

 the last-named may be mentioned a variety with fine spherulitic 

 outgrowths from quartz-phenocrysts. Other fragments present are 

 quartz-schists, and vein-quartz pebbles which have been completely 

 crushed into a mosaic before entering into the conglomerate. All 

 these are, however, quite outnumbered by the normal quartz- 

 pebbles and quartz-grains, some well rounded, others quite angular, 

 the whole being cemented by a small amount of muddy matrix 

 deeply stained by limonite. 



1 ' Handbook to the Greology of Shropshire' 1884, p. 25. 



