80 THE OLD RED AND CARBONIFEROUS PERIOD. CHAP. 



of the Irish carboniferous group (yellow sandstone and carboniferous 

 shale). What seems ascertained truth is the close approximation 

 in time, in character of deposition, and in forms of life, of the South 

 Hibernian and South Welsh rocks ; while the North Devonian 

 strata contain with these a somewhat lower group, not distinctly 

 represented in Wales or Ireland. 



This period is not represented in the area of Malvern, nor, in 

 fact, in any district to the northward ; only faint indications of 

 it can be admitted in the vicinity of the Forest of Dean, Tort- 

 worth, and Bristol. This seems to arise from no local removal 

 of such deposits ; they appear to have never reached so far 

 northward. We may probably admit as a sufficient explanation 

 the removal of the whole area in question from the influence of 

 the southern or, as we may call it, the Devonian Sea, and as the 

 best supposition to account for this, a partial re-elevation of the 

 district. 



The sequence of life is broken in the same degree as the series 

 of strata ; but a very large proportion of the Devonian fauna is 

 continued into the cognate though later carboniferous period. 



II. THE CARBONIFEROUS LIMESTONE. 



The carboniferous limestone appears in a considerable mass, half 

 surrounding the coal-field of Kingswood, in the south-west corner 

 of the Geological Map (Plate I). It is well seen at Wick war, where 

 the railway tunnel penetrates the rock. It is there a grey, par- 

 tially crinoidal rock, with some of the usual fossils, but not in such 

 abundance or variety as in the prolific gorge of the Avon at Bristol. 

 Haematite occurs in the fissures. 



At Bristol the strata are seen highly inclined in grand cliffs ; 

 all the beds are traceable from the uppermost below what represents 

 millstone grit to the old red sandstone. This is the whole series 

 in general terms d : 

 Millstone grit. 



c. Alternations of limestone, reddish, grey, or dark, with shales 

 of the same tints, and sandstones red or grey. Corals, 



J De la Beche in Mem. of Geol. Survey, vol. i. 



