284 



QUARTZ ROCK OF THE STIPER STONES. 



of Linley watered by the stream issuing from the defile. (See the vignette at the head 

 of this chapter.) 



Although the Heathmont, west of Linley, constitutes geologically the south-western 

 termination of this ridge of quartz rock, and Pontesbury their north-eastern extremity, 

 thus giving the range a length of ten miles, the central or lofty portion for about four 

 miles is alone known in the country under the name of the " Stiper Stones." 



When I first examined these rocks, I felt a difficulty in comprehending their true 

 nature, not being at that time acquainted with those of similar structure, which on the 

 flank of the Caradoc and the Wrekin have been proved to be simply altered deposits. 

 A second visit to this ridge dispelled the obscurity. Instead of a chaos of broken 

 masses, split by numerous joints which had become open fissures, and piled up in heaps 

 very like the grouping of certain basalts, I was then able to trace lines of stratification, 

 which although obscure in the centre of the masses, marked a dip to the N.N.W., 

 varying from 40° to 70°. Though many large loose blocks have rolled down on both 

 sides of the ridge, they are in much the greatest abundance on the eastern face, where 

 they have fallen from the escarpment and are strewed down the steep slope in deltoid 

 e£ ecroulemens." 



The rock of the Stiper Stones is quite analogous to that of the Wrekin and of the 

 Caradoc, exhibiting passages from compact and granular quartz rock into quartzose 

 grit and sandstone having a regular bedding. In its most crystalline form it is in- 

 tersected by numerous veins of vitreous quartz, and when weathered, numerous small, 

 white facets of quartz crystals are exposed, in vivid contrast to the dull brown colour of 

 the heath on which they lie. That these are merely fused sandstones, in which the 

 traces of mechanical deposit have been rendered obscure, is seen both by following 

 the ridge upon its strike to the N.N.E. or by tracing the passage of the quartz grits into 

 the overlying strata. In the first case, in tracking these rocks to the north-east, we 

 no sooner quit the flanks of this convulsed district of mines, than we find a zone 

 of quartzose grit and sandstone passing into a conglomerate which extends along the 

 hills of Bleak Moor, &c, the ends of the strata being best exposed in Nils Hill near 

 Pontesbury. 



At Nils Hill the quartz ridge may be completely investigated in two transverse combs, in the 

 northern of which the rock is largely quarried for the roads of the adjacent district. It is at least 

 200 paces wide, and the strata in the principal quarries dip 60° and 70° to the W.N.W. and strike 

 15° to 20° to the east of north and west of south. The upper beds are thin, and succeed each other 

 rapidly, without interposed laminae of a different substance ; but the underlying strata towards the 

 centre are two to four feet thick, with occasional traces of way boards of sandy shale, the lowest 

 beds being pebbly quartzose grits, separated by laminae of steatitic greenish shale. Throughout 

 large portions, however, the character of granular quartz rock is nearly as well maintained as in 

 the peaks of the Stiper Stones. On the surface of some of these beds are broad, wavy undulations 

 and even ripple-marks so common to arenaceous deposits. Together with these, are also ramose 

 casts, which, though strongly indicative of organic origin, could not safely be referred to any known 



