1 86 CARBONIFEROUS. 



The term Rotherham Red Rock has been applied to beds of iron-stained Coal- 

 measure sandstone, which occur at different horizons. These beds are generally 

 included by Prof. A. H. Green with the Middle Coal-measures. In this series he 

 places the Red Rocks of Rotherham and Harthill, which are quarried for building- 

 purposes and for scythe-stones and grindstones. In the same series the sandstones 

 designated by the followmg names (chiefly from localities where they are quarried) 

 are of economic importance for building-purposes, etc. : — Wickersley (grindstones 

 much used by cutlers), Houghton Common and Pontefract, Dalton, Brierly, 

 Cadeby, Ackworth, Upper and Lower Chevet rocks, Houghton, Treeton, Ackton 

 and Oaks, Woolley Edge, Abdy, Kent's Thin and Thick rocks, Barnsley, Emly, 

 High Hazles, High Hoyland, Handsworth, Woodhouse, Horbury rock (between 

 Bretton and Ossett), Kexborough, Manor, Birdwell, Thornhill, Park Gate and 

 Birstal, Silkstone, Sheffield, and Falhouse rocks. 



In the Lower Coal-measures there are also many sandstones serviceable for 

 building and for paving, as the Penistone flags, Grenoside and Farnley rocks, 

 Oakenshaw and Clifton rocks, Bradford and Elland flagstone. Idle, Wharncliffe, 

 and Middle rocks, Brincliffe Edge and Greenmoor rocks, Loxley Edge rock, and 

 Crawshaw sandstone. Some flags of a size twelve feet square have been obtained. 

 Thin beds are locally used for roofing. The flags are largely used for paving the 

 streets of London, etc. At Almondbury, near Huddersfield, stone has been 

 hardened for road-metal by being burnt. ^ 



In the Lower Coal-measures the Potternewton stone, is largely dug for building- 

 and paving-purposes near Leeds. The stone, consisting of fine grit and sandstone, 

 is very variable, the hard massive beds seen in one place deteriorating rapidly, 

 and passing into shaly beds in another. Quarries are filled up and deserted, as 

 soon as all the good stone has been worked out. 



The Sheffield grbidstonc is a hard and coarse stone used for common purposes ; 

 it is found at Ardsley, fourteen miles north of Sheffield. The Sheffield bhie stone 

 is a fine-grained stone, used for finishing fine goods. The act of grinding on a 

 blue stone is termed ^ ^ohifteni tig' —ihe. Sheffield whittle from the earliest periods 

 being in all probability ground on this stone.- Scythe-stones have been manu- 

 factured in Derbyshire. Near Rotherham a variety of Reddle, or Raddle, is 

 obtained, which is much used for polishing lenses, etc. 



6. ASHBY-DE-LA-ZOUCH OR LEICESTERSHIRE COAL-FIELD. 



There are four separate divisions of the Leicestershire Coal-field, 

 three of which only are productive. Of these three, two are on 

 the east and one on the west side of Ashby respectively ; that on 

 the north-east being spoken of as the Coleorton, and that on the 

 south-east as the Ibstock and Bagworth Coal-field. The district 

 to the west is the Moira, Gresley, and Swadlincote Coal-field. The 

 intermediate district near Ashby contains the lower beds of the 

 series, which are unproductive. The following divisions are made 

 in the Coal-measures : ^ — 



Uppei- Series. — Coarse grits of Moira and Newall, resting unconformably on 



lower beds. 20 to 50 feet. 

 Middle Series. — Sandstones, shales, and clays, with about twenty coal-seams, 



of which ten are workable, 1500 feet. 

 Lower Series. — Shales and sandstones, with a few seams of coal beneath the 



Heath-end coal, 1000 feet. 



^ C. Tomlinson, P. Geol. Assoc, i. 50. 



2 Descriptive Guide to the Museum of Practical Geology, by R. Hunt and F. 

 W. Rudler, edit. 4, 1877. 



^ See E. Mammatt, Geological Facts, etc., of the Ashby Coal-field, 1834 ; E. 

 Hull, Geology of Leicestershire Coal-field (Geol. Survey) ; and W. J. Harrison, 

 Geology of Leicestershire and Rutland, 1877. 



