BASALTIC IRON ORE OF ANTRIM. 435 



beach. This ore was formerly collected and smelted, but of late 

 years the works have been suspended. 



On the north-west coast of the Isle of Wight near Yarmouth a 

 clay ironstone was formerly collected to the amount of several hundred 

 tons a year. 



Iron Ore of Antrim. In County Antrim interstratified with the 

 basalt are a number of ferruginous bands, which occur above each other 

 like seams of coal. They are well seen in the cliffs near Down Hill, and 

 usually consist of a ferruginous clay called " bole," with an underlying 

 layer of lithomarge. The most important bed, which has been worked 

 commercially, and is used in the Cumberland iron furnaces, is seen at 

 Port-Moon, immediately under the lower tier of basaltic columns. It 

 consists of pisolitic iron ore of brown or reddish colour ; it contains 

 a good deal of fossil wood replaced by limonite. The thickness of the 

 bed is about two feet. Beneath the pisolite is six feet of bole, a 

 yellowish red ochre containing nodules of basalt, and this rests upon 

 twenty-five feet of lithomarge. The pisolitic ore yields from 40 to 60 

 per cent, of metallic iron. The bole contains about half this amount 

 of iron, while in the lithomarge the quantity of iron is too small to 

 render it of any commercial value. There can be no doubt that the 

 iron of this district has been derived from the decomposition of the 

 basalt, and in this connection it is interesting to bear in mind the 

 large percentage of iron that sometimes occurs in basaltic rocks, such 

 as those of the Sandwich Islands. 



The tertiary iron ore of Antrim extends along the coast from 

 Cushendall to Carrickfergus, and for a distance inland, which varies 

 from two to ten miles. 



Important mines are situate at Glenarm, Carinlough, Cargan, 

 Xewton Crommellin, Glenariff, and Irish Hill near Ballyclare. 1 



European Iron Ores. 



Spain. The larger part of the foreign ores of iron imported into 

 this country is derived from Spain. It is found in the Carboniferous 

 limestone near Bilbao, ranging as far as 19 miles north-west of that 

 town. The principal ore is brown hematite with some spathic iron. 

 It is quarried at the surface, and is worked chiefly in the Somorrostro 

 district. Other iron mines occur near Carthagena, Santander, Granada, 

 and in Catalonia. 



Portugal. In Portugal lodes of magnetic oxide of iron or magne- 

 tite occur in the Serra dos Monges in Alentejo. Other ores occur at 

 Moncorvo and at Quadmaril in Tras os Montes. 



France. The iron ores of France are chiefly contained in the 

 lower secondary rocks. The most important deposit extends from 

 Luxembourg through Lorraine to beyond Nancy. It occurs in the 

 Upper Lias. Other beds of the same age are found near Privas and 

 La Voulte in Ardeche. 



1 Iron Ores of Antrim, J. D. Kendall, Proc., " North of England Institute of 

 Mining Engineers," voL xxx., 1880. 



