Vol. 57.] AMONG THE MALVEKN CAMBRIANS. 157 



the Shales and the May Hill Sandstone. Phillips, with De la Beche, 

 evidently believed that the igneous rocks were in part con- 

 temporaneous volcanic rocks, the outpouring of which, according 

 to De la Beche, ceased with Llandeilo times. ^ Phillips, however, 

 compares the igneous rocks of Tortworth with ' the greenstones of 

 the lowest Caradoc Beds of Malvern,' remarking that the latter 

 were 'effused on the sea-bed' during the 'early Caradoc' period.^ 

 Strickland imagined that the great movements which elevated the 

 Malvern Chain and overturned the beds to the west were connected 

 with this igneous action.^ In 1862 and 1867 Timins^ published 

 chemical analyses ot many of the igneous rocks associated uith the 

 Cambrian strata of the Malverns ; and HoU in 1865 described them 

 as a series of contemporaneous ashes, grits, and lavas.^ In 1869 

 Symonds,^ who had already "^ supported Murchison's views, and had, 

 moreover, maintained that submarine volcanic action was responsible 

 for the production of the trap in the Black Shales, and for the 

 volcanic grits of the Hollybush Sandstone, spoke of pumice and scoriaB 

 in the shales, and imagined tlie former existence of an isl.md-volcano 

 surrounded by deep sea. In 1874 the same author " referred to 

 one of the igneous rocks (106 in the present writer's map^) as one 

 of the outworks of a volcano the roots of which were situated in 

 Raggedstone Hill. In 1884 he spoke of the Hollybush Sandstone 

 as probably a consolidated mass of volcanic grit and ashes, erupted 

 from a vent occupying the position of Raggedstone and Midsummer 

 Hills, but he considered the traps of Fowlet Earra and White- 

 Leaved Oak to be probably of later date than those interbsdded with 

 the Shales.^" He further stated that the igneous rocks near Bronsil 

 and Howler's Heath occupy the position which in North Wales is 

 taken up by the Lower Silurian Beds [o]) cit. p. 4'2). In 1889 Symonds 

 further maintained thnt the old lavas erupted through the Hollybush 

 Sandstone and Black Shales occupy the position proper to the Llan- 

 deilo and Caradoc Beds." Mr. Teall in 1888 recognized the presence 

 of ophitic diabases in the Malvern Cambrians, ^^ In 1898 Prof. Lap- 

 worth considered the majority of the igneous rocks associated with 

 the Cambrian strata to be intrusive. ^^ The present writer in 1899 

 and 1900 recognized in these igneous rocks a series of intrusive 



1 Mem. Geol. Siirv. Gt. Brit. vol. i (1846) p. 38. The Malvern Black Shales 

 were then regarded as of Llandeilo aee. 



2 Ibid. vol. ii, pt. i (1848) pp. 194 & 195. 



3 Phil. Mag. ser. 4, vol. ii (1851) p. 359. 



^ Edinb. New Phil. Journ. ser. 2, vol. xv (1862) p. 1, and Quart. Journ. 

 Geol. Soc. vol. xxiii (18()7) p. 352. 



" Quart. Journ. Geol. Soo. vol. xxi (1865) pp. 87 et seqq. 



« Trans. Woolhope N. F. Club, 1869. p. 6. 



^ ' Old Sboues ' 1st ed. (1855 1 pp. 31 & 43. 



^ Proc. Geol. Assoc, vol. iii (1874) p. -i71. 



« Quart. Journ. Geol. Soc vol. Iv (1809) pi. xiii & p. 167. 

 i» • Old Stones' '2nd ed. (1884) pp. 25, 26, & 30. 

 " • Flora of Herefordshire' 188.>. 

 12, ' Briti.sli Petrography ' 1888. p. 245. 

 ^^ Proc. Geol. Assoc, vol. xv (1898) p. 3.'^8. 



