CORN STONE FORMATION IN SHROPSHIRE. 



179 



of the Old Red Sandstone. I may particularly cite the escarpment of the Skirrid, 

 three miles north of Abergavenny, and the cliff called the Daren, north of Crickhowell, 

 as situations where they may be seen in countless profusion, imitating in their outline, 

 horse- shoes, rings, almonds, &c. It is quite manifest that by exposing rocks of the 

 varied composition of these in question, to the action of running water, as in the Sapey 

 Brook, or to long-continued atmospheric influences, as in the Skirrid, the inevitable 

 result would be the wearing away of these blotches or concretions, which are softer than 

 the inclosing mass of rock 1 . 



There is no district in which the nature and relations of the cornstone can be better 

 studied than to the north of Ludlow, where the formation occupies a distinct range of hills 

 rising to the height of four or five hundred feet above the low country, and presenting 

 escarpments to the valley of Corvedale. In these hills are several calcareous zones, 

 separated by thick masses of sandstone, flagstone, and argillaceous marl, the strata 

 dipping slightly to the north and south of east. 



Some of the best flagstones of these hills are quarried at Bouldon. The upper beds consist of 

 red marl, impure cornstone, and thin beds of deep-coloured red sandstone. Beneath these lie about 

 twelve feet of sandstone, which splits into flags. This stone is of a greenish colour and highly mi- 

 caceous, and its surfaces are marked by those undulations or ripple-marks, so frequent in the 

 sandstones of all ages, and which are supposed to have resulted from the action of water during the 

 process of deposition. The flags are from three to eight inches thick, and sometimes of great extent, 

 and they are largely used for staircases, doorways, wall tops, lintels, Sec; a course of impure corn- 

 stone underlies the flagstone. Similar flagstones but generally of dull red colours are extracted 

 at the southern end of the Brown Clee, and on the south-western slopes of the Titterstone Clee. In 

 the quarries of Sir W. Boughton, Bart., at Downton Hall, flags are often quarried of the great size 

 of one hundred square feet. 



A section of the strata between the slopes east of Downton Hall and the valley of 

 Corvedale is seen by reference to PI. 31. fig. 3., and the structure of these beds is al- 

 ready sufficiently explained to render unnecessary the encumbering of these pages 

 with similar details in other places. The courses of concretionary limestone are as 

 usual not continuous • on the contrary, they expand and diminish, disappearing and 

 reappearing in their horizontal range. 



Similar exhibitions of concretionary limestone wrap round the sides of the Clee Hills. 



1 I was indebted to Mr. Jabez Allies, of Worcester, for directing my attention to these forms in the stone 

 of the Sapey Brook, and concerning which he read an ingenious antiquarian memoir before the Natural History 

 Society of Worcester. In that paper, since published, he states the following tradition of the district. A mare 

 and her foal having been stolen from St. Margaret of Audley, the patron of the adjacent chapelry of Sapey, 

 the track of the stolen animal, and also of the pattens of the woman who led them down the bed of the brook, 

 were by the wrath of Heaven left as ineffaceable marks of the impious crime. This is no doubt a monkish 

 legend, in which a natural phenomenon was made preternatural, to work on the credulity of the age, and is 

 worthy of being added to the story of St. Bridget of Whitby, who through her intercessions turned all the snakes 

 of that district into stone, these snakes being the ammonites of the lias ! 



