THE IRON OF THE BLACK COUNTRY. 431 



Blue Flats, White Flats, Pennystone and Black Flats. The ore yields 

 about 35 to 38 per cent, of metallic iron, the nodules are usually 

 brownish grey, often have a septarian structure filled with crystals of 

 sulphate of baryta. Occasionally the iron contains minute traces of 

 other metals. It is chiefly worked at Lillieshall, Madeley Court, and 

 Madeley Wood, Ketley, Wombridge, and Packmoor. 



In North Staffordshire the chief ironstone bands are the Eed 

 Shag, which has a reddish-brown fracture, and occurs at Hanley and 

 Newcastle, the Gatter Mine at Hanley, the Eed Mine, Cannel Mine, 

 Pennystone, and Deep Mine. The percentage of metallic iron varies 

 from about 32 to 40 in the different beds. 



In South Staffordshire Dudley is the centre of the iron manu- 

 facture, which covers an area of about 50 square miles. The district, 

 commonly known as the Black Country, extends from Wolverharnpton 

 by Bloxwick to Walsall, from Walsall to Halesowen, to Stourbridge, 

 and from Stourbridge to Wolverharnpton. The district includes seven 

 important towns and sixteen large villages. The quantity of ironstone 

 is probably greater than is to be found in any similar area within the 

 same vertical space. Professor Jukes enumerates fifteen principal 

 bands, which vary from two or three feet to thirty or forty feet in 

 thickness, though the ironstones usually occur in dark clay called 

 clunch or clod, which forms much of the thickness of the bed. Thus 

 the Gubbin and Balls ironstone is seven feet thick, but only contains 

 two feet of ironstone divided by three beds of clod. The Balls have 

 a septarian structure, the septa being lined with iron pyrites, and 

 sometimes with galena and blende. 1 



North Wales. Argillaceous iron ore occurs in the Euabon coal-field 

 at Trefechan in about six or seven bands. In Flintshire the iron is 

 found in the Carboniferous limestone near the Talargoch lead-mine, and 

 contains a little cobalt and nickel. 



The South Wales iron ores were formerly mined on the outcrop 

 by means of races or streams of water directed on the ore, and then 

 the ironstone was converted into oxide of iron and smelted. The 

 lower coal measures contain the bulk of the beds of iron ore and coal. 

 They extend over the whole coal-field ; the yield of iron is richest in 

 the east, and in the west the beds are thicker and poorer. The beds 

 are extremely numerous, but rarely of any great thickness. The bed 

 known as the Three-quarter Balls in the eastern part of the basin is 

 about three feet thick. The iron beds are well worked in the Ebbw 

 valley. 



Irish Carboniferous Iron Ore. The Leinster coal-field in the 

 south yields carbonate of iron, but most of the ironstone, which occurs 

 in nodules and concretionary masses, is found in the northern district of 

 Leitrim, Tyrone, and Antrim. 



In County Wicklow Mr. Tichborne has described a vein of mag- 

 netic oxide near Kilbride, which is two to three miles long, and some- 

 times six feet wide. Limonite occurs in the mineral veins at Cronebane. 



1 Jukes, " Iron Ores of Great Britain," Part ii., Mem. Geol. Surv., 1858. 



