220 CARADOC SANDSTONE OF THE HOAR EDGE, FRODESLEY, ETC, 



here nearly vertical, and much distorted* there can be no doubt they underlie all the 

 system above mentioned. Indeed, they are dissimilar in mineral composition to any 

 of the overlying strata. From their red colour and the great admixture of clay and 

 marl, which are associated with them, they might be lithologically identified with many 

 beds of the Old or even of the New Red Sandstone, described in previous chapters. 

 The section of the Onny does not clearly expose any lower beds in the series. The 

 black brittle schist which succeeds, may possibly represent a portion of the Llandeilo 

 flags, but apparently it contains no fossils. In this section, indeed, the Caradoc forma- 

 tion has its natural termination at Horderly-gate, for, as will hereafter be shown, this 

 point being upon a line of trappean eruption, the strata are thrown off in an anticlinal 

 form. 



At the north-eastern end of the Caradoc and Lawley hills, the lower sandstones are 

 much more fully developed than on the banks of the Onny. In a traverse from the 

 hills of Church Preen, by Broome to Chatwall, we pass over the overlying strata, con- 

 sisting of impure limestone, shelly flagstone, sandstone, and grits before mentioned, the 

 inclination of the lower strata increasing as they approach the ridge of the trap, (see 

 coloured view, facing p. 216, and PL 31. f. 4.). Thence travelling across a valley of 

 denudation, which has been excavated in shale, we find a bold and sharp ridge of sand- 

 stone and grit, rising up into the Hoar Edge, and running parallel to the general strike 

 of all the other strata, and to the Caradoc and Lawley ; the angles of inclination of the 

 beds having increased to sixty degrees. In the quarries the descending section consists 

 of— 



1. Grits and coarse sandstone, of brown and yellow colours. 



2. Pure, white, fine-grained sandstone, the interstices between the grains being occasionally filled up with decomposed 

 felspar, which, when abundant, gives in certain states of decomposition a yellowish and freckled aspect to the rocks. 



3. Yellowish sandstone, with ferruginous streaks and stripes of blue, red, and yellow colours. 



4. Deep red sandstone. 



5. Whitish gritty sandstone. {Dip 55° to 60° S.E.) 



The beds in -all are about fifty feet thick. Troughs of very large size are extracted, 

 and much of the stone is of very superior quality, being quite equal to many esteemed 

 building-stones in the carboniferous system, from which indeed it is undistinguishable 

 in hand specimens. These quarries expose but a small portion of the strata of which 

 the Hoar Edge is composed, and the inferior strata lying between this ridge and the 

 Lawley have been much denuded, leaving a deep, narrow, intermediate valley ; but 

 upon their strike to the south-west, between Enchmarsh and the little Caradoc, the 

 sandstone and grits expand considerably, and contain many of the fossils to which we 

 have alluded. In the next chapter it will be shown that where the sandstones and grits 

 have been cut through by the eruptive trap rocks of Caer Caradoc, they have been 

 thrown into vertical, broken, and fantastic forms, and in many places altered into 

 quartz rock. The zone of bright yellow colour on the eastern edge of the Caradoc and 

 Lawley Hills, as represented in the coloured view, p. 216., indicates the position of the 



