1 88 CARBONIFEROUS. 



Upper Coal-measures. But "The Potteries" are especially noted 

 for china-ware, which is the product of china-clay from Devonshire 

 and Cornwall, of gypsum from Chellaston, chalk-flints from the 

 South of England, and chert from Derbyshire.^ Peacock Coal has 

 been found at Hanley. 



9. SOUTH STAFFORDSHIRE OR DUDLEY COAL-FIELD. 



Although mainly situated in South Staffordshire, yet this Coal- 

 field extends into the adjoining counties of Warwick, Worcester, 

 and Salop. It extends from Cannock Chase on the north to 

 Halesowen, including the country east of Wolverhampton, and 

 around Bilston, Wednesbur}^ Tipton, etc.- The beds comprise : — 



Upper Series. — Consisting of red, green, and mottled clays, red and grey- 

 sandstone, etc., Soo to 1300 feet. 



Middle and Lower Series. — Shales, sandstones, etc., with thick coals, ironstone, 

 etc., 400 to 510 feet. 



Marine mollusca occur in the ironstones, including Discina, 

 Producta, and Conularia. Fish-remains occur, such as Huloptychius, 

 Mcgalichthys, and Cochliodus ; and also Arachnida. 



At Parkfield Colliery, near Wolverhampton, many stumps of trees 

 have been laid bare in an open work of the Coal-measures ; no less 

 than seventy-three fossil trees have been counted in the space of 

 a quarter of an acre. Hence this "Fossil Forest" has attracted a 

 good deal of attention.^ 



The occurrence of a boulder of quartzite in one of the coal-seams 

 has been noted by Prof. T. G. Bonney.^ 



The most remarkable seam in the Dudley district, or indeed in 

 the British Islands, is the 'Ten yard' or 'Thick coal,' which has a 

 general thickness of 30 feet. This, however, is due, as Mr. 

 Jukes has pointed out, to the fact that over a considerable area 

 a number of coals come together, resting one upon another, 

 with little or no interstratified shale or partings. The number 

 of beds composing this thick seam is reckoned at from 10 to 

 14 in different places. The thick coal is maintained more or 

 less completely over all the district around Dudley as far as 

 Bilston, Wednesbury, Halesowen, and Kingswinford. At Fox- 

 yards, two miles north of Dudley, this coal-seam was obtained 

 formerly by "open work" in a large quarry. Eventually it splits 

 up into ten seams with a total thickness of 500 feet of strata. 



Cannock Chase and Walsall are localities of importance in this 

 Coal-field ; and the Rowley Rag basalt is well known in connection 

 with the district ; according to Jukes, it forms part of the Coal- 

 measure Series, having been poured out as a sheet of lava during this 



1 Hull, Coal-fields, edit. 4, p. 193. 



2 The South Staffordshire Coal-field, by J. B. Jukes, edit. 2, 1S59 (Geol. 

 Survey). 



^ See H. Beckett, Q. J. i. 41 ; and Proc. Dudley Geol. Soc. iii. 128. 

 * G. Mag. 1873, p. 2b9. 



