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ments everywhere affected these strata, for we have numerous examples, as at 

 Woolhope, Shucknell, Usk, and other localities, where the under lying Upper 

 Silurians have been upheaved through the overlying Lower Old Red Sandstone. 

 If the Woolhope Club wish to study the effect of earth movements and upheavals, 

 also of denudation, I should recommend their paying a visit to the northern 

 district of Siluria, to the Forest of Hayes on the Long Mountain, or to Clun 

 Forest on the borders of Shropshire, bearing in mind the position of the Lower 

 Old Eeds in the Ledbury, Ludlow, and Kington districts. The Clun Forest 

 country is a fine study for the young geologist, who can there mark the physical 

 teaching of outliers, with their history of denudation, and behold the evidence 

 of earth movements and upheavals in the elevation of the Upper SHurians, 

 with the Lower Old Reds resting upon them, and upheaved with them. 



There are four outliers of Lower Old Red, separated by SUxxrian hill masses, 

 around the picturesque town of Knighton. There is the Clun outlier, and the 

 Bettws-y-Cryn outlier, with two smaller patches west of the Teme, and an outlier 

 north of Knighton. 



Near Presteign we find a large mass of Lower Old Red running northwards ; 

 west of Brampton Bryan, these strata, like those of Clun Forest, are elevated 

 with the Silurian hiUs ; and south of Presteign there is a patch of Old Red of the 

 greatest interest, as indicating the former continuity of the Lower Old Red over 

 the Silurians in this part of the country. It is called Lower Radnor Wood, and 

 lies just west of the upcast of the Woolhope limestone by the Stanner trap, 

 which looks as if the Stanner rocks were not injected and erupted through the 

 Woolhope beds until after the deposition of the Old Red. I might mention many 

 other examples within the cognizance of the members of this society, but I 

 select themogt striking, as it is impossible to examine aU these isolated patches of 

 a great formation without feeUng positive that the strata were once continuous 

 with those of the Hereford and Ledbury country on the south. 



I do not know a more interesting exploration for the geologist than to take 

 the section from the Upper Silurian rocks of Llanstephan, and Craig-pwll-du, to 

 the summit of the Black Mountains, which are capped by the Upper Old Red 

 Sandstone, the encampments of which stand out so boldly above the plains. 

 The rocks on the summit dip to the south under the Old Red conglomerate 

 and Carboniferous Limestone of the South AVales coal field. I could say much 

 respecting the denudation of these upper Brownstones of the Old Red, which 

 once extended far beyond the edges of their present boundaries over the vales of 

 Herefordshire and Breconshire ; but the position in this country of certain rock 

 masses consisting of Carboniferous Limestone, and Millstone Grit, tell the history 

 of denudation perhaps even more vividly than do the Old Red summits of the 

 Brecon and Caermarthen vans, or those of the Black Mountains of Llanthony, 

 and the Hay, which once stretched far over the now denuded Wales. All i hose 

 who love the lore of the rocks will not fail to have remarked during their expedi- 

 tion this day how the Old Red Sandstone of Hereford is overlaid by the hiU 



