170 



GEOLOGY OF THE WOOLHOPE DISTRICT. 



By the Rev. ROBERT DIXON, M.A. 



Swiofioaav yap, oiTiq t)(^ftiaTOi to nplv, 



JIvp Kui GaXacaa. ^sch. Agam., 650. 



For Fire and Ocean, erst most deadly foes. 



Swore fast alliance. Eng. Trans. 



The remarkable district from which our club derives its name has 

 already been fully described by Sir R. Murchison, in the "Silurian System," 

 and by Professor PhiUips in the " Blemoirs of the Geological Survey " ; these 

 books, however, besides not being easily accessible, are somewhat out of date in 

 the nomenclature of rocks and fossils. The new edition of "Siluria" only refers 

 incidentally to the distiict. It was felt, therefore, that notwithstanding the 

 existence of these standard works, there was still wanting a plain account of 

 the district, written with the object of enabling those who are but moJerately 

 conversant with the principles of geology to understand and woi'k out for them- 

 selves its details : this want I have attempted to supply. 



GENKEAL ACCOUNT, 



The Woolhope district presents the ijhenomenon of a valley of elevation, 

 the most symmetrical according to Murchison in the British Isles : even the 

 world-wide traveller Humboldt has deigned to refer to it in the "Cosmos" 

 (vol. v., page 231, ed. Bohn), as an example of one of the less common results 

 of what he caUs Vulcanicity. These valleys are formed by the upheaval of a 

 tract of country by a force originating in the earth's interior round an axis, 

 accompanied by a removal by the action of water of the chaotic fragments thus 

 torn from the main mass. It is evident that the extent of the upheaval and 

 the depth of the stratified beds, which rise to the surface, will depend upon 

 the intensity of the uplifting force, and the result will be that earlier deposited 

 beds vrill be stripped of their covering, and appear on the surface, while the 

 overlying beds wiU form an escarped ridge encircling and enclosing a valley. 

 The beds underlying the Old Red Sandstone of Herefordshire are as follows, 

 with the maximum thickness in oiu- district, as deduced from the vei'ticai 

 section of the sui'vey : — 



feet. 



^Downton Sandstone S2 



^ -T— -._,,, -, . ) Upper Ludlow 128 



LUDLOA\ Series < Aymestry Rock 40 



^. Lower Ludlow 694 



(■ "Wenlock Limestone 148 



"WENLOCK Series< AVenlock Shale 1084 



( Woolhope Limestone and Shale 208 



TTppi 



(MT-^im?"'''''^ Sandstone | g^^^ ^^^^ ^^^^ 



