212 Mr. AiKiN on the Wrekln, ^c, 



buted here and there in the flat ground of Stretton valley ; they rest 

 on the aggregate sandstone already mentioned, and rise E.S.E. at a 

 small angle towards the Lawley and Caer Caradoc, in the parallel of 

 which they are situated, but they entirely cease in the more con- 

 tracted part of the valley, a little further to the south, where the trap 

 of Ragleath hill is evidently incumbent on the transition (or, perhaps, 

 newest primitive) c/ay slate, which breaks out to-day in the streets of 

 Church Stretton. 



From these facts it appears that the line of elevated ridge-hills from 

 Lilleshall to Ragleath is an unstratified mass of rocks of trap-forma- 

 tion incumbent on highly elevated strata of transition slate : that on 

 the eastern side of this mass there is a great deposit of stratified rocks, 

 consisting of quartz-grit ; of a micaceous sandstone nearly allied to 

 greenstone ; of a sandy slate-clay ; of limestone, slaty marl and sand- 

 stone slate in alternating beds ; and of the independent coal-forma- 

 tion : all rising up parallel, or nearly so, with the trap at a horizontal 

 angle, the magnitude of which decreases, in proportion to the distance 

 of each bed from the trap, unless where interrupted by casual and 

 local causes. That on the western side of the trap, the mass of de- 

 posits is very small, consisting of a sandstone composed of angular 

 fragments, on which rests a thin broken coal-formation. That the 

 old red sandstone bounds the whole of this series of rocks on the east, 

 north, and north-west, but though in contact, appears to be perfectly 

 unconnected with them. 



The trap-formation itself does not seem to correspond with any of 

 those described by mineralogical writers, and its essential characters 

 are, its unconformableness with the transition slate on which it rests, 

 the great abundance of claystone, both massive and vesicular, which 

 it contains, and the presence of actynolitic amygdaloid. 



