1 82 CARBONIFEROUS. 



Strata dip seawards, much of the Coal-field is beneath the waters 

 of the Irish Sea. Inland the Coal-measures extend to Aspatria. 

 The following divisions are made in the rocks of this tract : — 



Upper ^6'r;V^.— Purplish-grey sandstones of Whitehaven, lOO to 150 feet. 

 Middle Series. — Developed at Cleator Moor, containing 7 workable coal-seams. 

 Loiuer Series. — Containing 4 or 5 thin and inferior coal-seams. 



The seams vary from 2 to 7 feet in thickness. It has been a 

 matter of some dispute whether the Whitehaven sandstone should 

 be classed as Permian or as Coal-measures. Sedgwick regarded it 

 as Lower New Red Sandstone.^ But it is now generally grouped 

 with the Coal-measures, although, as seen in the cliff south of 

 Whitehaven, it rests unconformably on the Coal-measures beneath. 

 According to Mr. T. V. Holmes, it occupies the same position in 

 Cumberland that is held by the Red Rock of Rotherham in 

 Yorkshire.- 



At Workington the coal is obtained beneath the sea, the mines 

 extending two or three miles under water. The Coal-measures in 

 places rest on the Lower Carboniferous rocks. 



A small coal-field, consisting of true Coal-measures, and over- 

 lying 1000 feet or more of IMillstone Grit, was discovered by Mr. J. 

 G. Goodchild at Argill, near Brough in Westmoreland;^ and 

 this may give encouragement to those who hope to find workable 

 coal beneath the New Red rocks of the Vale of Eden. 



3. NORTH LANCASHIRE OR INGLETON AND BURTON COAL-FIELD. 



The tract of Coal-Measures near Ingleton is much obscured by 

 Permian and Drift Beds. It contains some beds of coal, i to 9 

 feet in thickness, which have been worked along its southern 

 border from Black Burton on the Greeta, eastwards, to the Craven 

 fault, south of Ine:leton.* 



4. SOUTH LANCASHIRE OR WIGAN COAL-FIELD. 



This important tract is broken up by faults and denudation into 

 several coal-fields. Thus it includes, in addition to the main coal- 

 field, those of Chorley (Coppul district), Burnley, and Manchester ; 

 a small tract in Cheshire near Stockport, sometimes called the 

 Cheshire Coal-field ; and the Goldsitch Coal-field, north of Leek. 

 The main district embraces St. Helens, Wigan (see Fig. 27),* 



^ T. G. S. (2), iv. pi. XXV. See also Sedgwick and W. Peile, Proc. G. S. 

 ii. 420. 



^ P. Geol. Assoc, vii. 409. 



^ Trans. Cumberland Assoc, part vii. p. 163. See also T. V. Holmes, part ix. 

 p. 109. 



* Geology of Kirkby Lonsdale and Kendal (Geol. Survey), by W. T. Aveline, 

 T, McK. liughes, and R. H. Tiddeman, p. 27. 



5 E. Hull, Q.J. xxiv. 328. 



