Border Countr?/ of Salop and North Wales ; 8^0. 241 



friction. The upper beds are still white, and somewhat approaching to chert. 

 Those underneath become ferruginous, and contain a few impressions of 

 entrochi and of curved cylindrical forms apparently of vegetable origin *. 

 The lowest bed, which is also the thickest, and far exceeds the others in 

 the height of its precipices and the size of its detached fragments, is of a 

 dark red colour, its grains of sand slightly cohering and glittering in the sun. 

 This rock descends to the river, which flows at the base of the escarpment, 

 and also dips under it from the opposite slope of the valley. Its broken and 

 precipitous faces are sometimes reduced by the action of the weather into the 

 form of irregularly rounded masses, and at other times are streaked by the 

 projecting lines of the harder siliceous veins. Pursuing the course of the river 

 from Llanvorda towards its head, we find beds of limestone rising from be- 

 neath the sandstone. 



The direct road from Oswestry to Llansilin leaves the spot now described 

 at the distance of about a mile to the north. It crosses similar beds, which 

 are extended over a greater space, because accompanied by no escarpment so 

 high and precipitious as that of Llanvorda. We first come to these beds after 

 passing Offa's Dyke about two miles from Oswestry. They are found through 

 the space of about two miles further along the sides of the road, and in quar- 

 ries and weather-worn cliffs. They appear to dip uniformly under one an- 

 other, with an inclination of about 30° to the horizon. The white cherty 

 beds are succeeded by a dark red sandstone, analogous to that which forms 

 the base of the escarpment at Llanvorda. Pebbles of quartz are disseminated 

 through it ; the summit of a considerable hill on the left hand of the road 

 called Mynydd Moel, consists of this sandstone. Its exposed cliffs are worn 

 into irregularly rounded masses, and resemble the usual appearances of the 

 red sandstone of Lancashire, Cheshire, and Shropshire. On advancing west- 

 wards we next come to a bed which lies under the red sandstone, and con- 

 sists of grains and small pebbles of quartz with a few pebbles of slate and 

 joints of encrinites, rather loosely aggregated by a calcareous cement. Lime- 

 stone of the same gray colour with the cement of this conglomerate immedi- 

 ately succeeds ; it abounds in corals, encrinites, and shells ; large quarries are 

 worked in it on each side of the road : it contains numerous veins, often an 

 inch or more in thickness, of the red sulphate of barytes. Towards tfte east 

 it slopes gradually with a dip conformable to that of the calcareous breccia 

 and the sandstones lying over it; whereas on the western side, looking to- 



* I am informed that bodies of the same kiad are found in the red sandstone at Manchester 

 and its vicinity. 



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