28 . BEroRT— 1873. 



Geology of ihe Cotmtry round Bradford, Yorkshire. 

 By E. ilussELL, C.E., F.G.S., H.M. Geolorjmd Survey*. 



Lithological Descnption. 



. The country which the author described lies between the river Wharfe and 

 Calder on the north and south, the towns of Leeds and Halifax on the east and 

 west, having Bradford in the centre. 



The measures included within this area belong to the Carboniferous series, 

 together with a few patches of drift clay, and gravel, and the alluvial deposits in the 

 river-valleys. 



The Carboniferous rocks may be divided as follows : — 



feet. 



Middle Coal-measures 850 



Lower Coal-measures 122(> 



Upper Grit, or Rough Rock, with flags at base .... 180 



Shales 110 



Middle Grit in several beds 1400 



Beginning with the lower beds, the author shortly described the lithological cha- 

 racter of each gi-oup in chronological order. 



The lower part of the Middle Grits consists of shale alternating with bands of 

 sandstone. The upper portion is principally sandstone with thin bands of shale ; and 

 the lowest bed of this division is the thick and massive rock which forms Ilkley 

 Crags and Otley Chevin. 



The flags at the base of the Upper Grit are fine-grained and regularly bedded ; but 

 they are not always present. 



The Upper Grit itself is a coarse-grained massive sandstone, varying from 80 to 

 180 feet in thickness. It generally occurs in one bed ; but northwards it lies in two 

 or three distinct beds. 



The Lower Coal-measures contain five workable seams of coal, ten thin coals 

 which occasionally attain a thickness of 1 ft. 2 in. and 1 ft. 8 in., and several beds of 

 sandstone, the principal of which are known under the names of the Elland Flagstone 

 and the Oakenshaw rock. 



The five principal coals and two sandstones maj' be described thus : — 



The Halifax Soft-bed coal maintains a very constant thickness of 1 ft. 4 in., to 1 ft. 

 8 in. from Halifax northwards, but eastwards it diminshes to a band a few inches 

 thick. ■ 



The Halifax Hard-bed coal varies from 2 ft. 3 in. in the south to 1 ft. 4 in. in the 

 north, and like the Soft Bed thins out eastwards to a thin band. 



The Fireclay below the Gannister, on which the coal lies, is often worked along 

 with the coal, being from 3 to 6 ft. thick. 



The Elland Flagstone includes a group of sandstones, which, being in general thin- 

 bedded and flaggy, give the name to the rock. It forms large spreads on the higher 

 ground around Northowram ; and west and north of Bradford the CO- yards rock of 

 Thornton seems to unite with it and form the thick sandstone at Gaisby Hill. 



The Better-bed coal is one of the most important and valuable coals in the 

 neighbourhood, attaining a thickness of 3 feet at Horton ; but the average thickness 

 is about 1 ft. 8 in. ; much value is set on this coal by the Iron Companies in the 

 district. 



The Black -bed coal is of a .softer nature and inferior qualitj', 2 ft. 4 in. to 2 ft. 6 in. 

 thick at Low Moor ; but at Farnley and Beeston the lower part of the seam is 

 converted into an impure stone coal. The value of this coal is enhanced by the 

 iroq^tone-bearing shale which overlies it. The layers of ironstone are imbedded in 

 a carbonaceous shale ; and the average thickness of good ironstone will be about 5 

 or 6 inches, that portion of it known as the " middle balls " being the richest in 

 metallic iron. 



The Oakenshaw rock is a well-marked and distinct sandstone over the whole 



* See ' Iron,' Nos. 39 & 40, vol. xi. New Series, pp. 458 & 491 ; also Geological Surrey 

 Memoir on the Yorkshire Coalfield. 



