WORSEL, HANTER, AND OLD RADNOR. 



319 



admixture of felspar and hypersthene, which contains veins of white calcareous spar and crystals of 

 iron pyrites. On one of the gnarled summits of these rocks are patches of a quartzose conglome- 

 rate, of which more will be explained in describing Old Radnor Hill. 



Worsel Wood. — This is the small central conical hill seen in the sketch prefixed to this chapter. 

 It is covered with trees and offers little of interest on the surface, but near its base I found dark 

 fine-grained compact felspar, and traces of the same varieties of trap as in Stanner, with much 

 disseminated calcareous matter. 



Hanter Hill. — In this hill, the most prominent of the group, are many of the modifications of 

 hypersthene rock described in Stanner ; the coarse-grained whitish and greenish felspar, traversed 

 by crystals of dark-coloured hypersthene being predominant. Some masses of this bold and conical 

 hill are of a slightly porphyritic structure ; others consist of slaty and concretionary felspar rock, 

 with crystals of common felspar. 



The coarser varieties of the hypersthene rock apparently occur near the summit, and in some of 

 them carbonate of lime is disseminated between the crystals of hypersthene and felspar. Iron py- 

 rites is common. 



Old Radnor Hill. — The mass of this hill is a dark greenstone or hypersthene rock, and with a 

 somewhat concretionary trap, which has a fragmentary aspect, owing to small cracks traversing the 

 rock. Masses of grey and pink compact felspar, passing into impure serpentine, are quarried near 

 the church. These and modifications of greenstone are also found in the knolls around the Brook- 

 kiln limestone quarries, &c. Nests and thin coatings of anthracite accompany the trap of Old 

 Radnor, as also crystals of copper and iron pyrites, 



53, 



a. Trap (Old Radnor Hill). b. Conglomerate. c. Limestone. 



Thrown off the western flanks of Old Radnor Hill (a of this wood-cut) is a peculiar conglome- 

 rate (b). It has a base of grey and green compact felspar, inclosing pebbles of quartz of the size 

 from a bean to that of a man's fist, and occasionally grains of quartz. From this composition it 

 may be inferred that a stream of compact felspar, or submarine lava, entangled in it the sand and 

 pebbles of a former bed of the sea. This conglomerate appears in various little bosses, and is well 

 seen on the sides of an old lane which ascends from Harpton Court to Stockwell. (Pimply rock of 

 Stockwell Scar.) 



On the actual side of the hill, and 200 to 300 feet below its summit, is a mass about forty to fifty 

 feet in width of the conglomerate grit, in almost vertical strata, having all the appearance of grey- 

 wacke grit. This passes beneath the limestone (c) . It is certainly a stratified deposit, occupying 

 the same place in the series as the volcanic grits of the Caradoc which underlie the Wenlock 

 limestone, and like them the pebbles and sand have been accumulated in the same manner with the 

 detritus of submarine volcanoes during the formation of the Silurian strata, the bedded masses being 

 afterwards thrown up by subsequent eruptions to their present positions. 



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