COMPARISON WITH SIMILAR ORE DEPOSITS ELSEWHERE. 279 



southward extends through New Zealand. Still farther southward the zone 

 extends through the Macquarie Islands, and beyond this, in antarctic regions, in 

 Victoria Land, where are the volcanic cones of Erebus, Terror. Melbourne, and 

 Discovery, of which one Erebus is in almost continuous eruption. 



The prolongation of the zone goes through the unexplored antarctic regions, 

 very near to the south pole, and on the other side there are Pleistocene and 

 recent volcanoes in the South Shetland Islands and other near-by land. Not far 

 beyond this the belt comes to Tierra del Fuego, a desolate volcanic region. 

 Thus the entire circuit of the earth has been made. This girdle, extending 

 around the world and measuring some 35.000 kilometers, has been called the 

 "circle of fire" by geographers, and is the theater of the world's most extensive 

 and active volcanic manifestations. Within this circle, in the Pacific Ocean, are 

 lesser volcanic belts." The major volcanic belt, when viewed on a globe or a 

 perpendicularly projected map, 6 has not a circular form, but rather that of a 

 great somewhat elongated rectangle, inscribed upon the sphere; the two longer 

 sides run northwestward and consist of the northwest American Pacific coast on 

 one side and the stretch from the Philippines to the south pole on the other; 

 the two shorter sides run northeastward and consist of that portion lying parallel to 

 the Asiatic coast line on the one side and that portion in and near the antarctic 

 regions on the other. This figure, however, is broken by irregularities consisting 

 of curves and angles; and the volcanic chains are characteristically arranged in 

 curves or "garlands,"'' though in many cases it may prove true that such 

 apparent curves are in reality combinations of straight lines, as is the case with 

 the changes of trend in the volcanoes of Java and Sumatra. <' 



The Pleistocene-Recent volcanoes of the East Indies belt, which began their 

 activity toward the close of the Tertiary,' have emitted chiefly andesites with a 

 less amount of closely related basalt. Hornblende or pyroxene andesite. or both, 

 occur in Java, Borneo, Celebes, and neighboring islands. Most of the pyroxene 

 andesites have more hypersthene than augite.-'" 



In New Zealand hornblende-andesites are common.'' Concerning the recent 

 lavas of the Macquarie Islands and other antarctic volcanic regions, there appears 

 to be little information; the lava of Mount Terror, in Victoria Land, is reported as 

 "basic."* 



a See Reclus, Elisee, Nouvelle geographic universelle, vol. 14. pp. 41. 42: Suess, E., La face de la terre, Paris, vol. 2, p. 

 837; Bonney, Volcanoes, London, 1899. pp. 259-260: Ferrar, H. T., Geog. Jour., Apr., 1905, pp. 374, et seq. 

 & Reclus, op. cit., p. 43. 

 c Suess, E., op. cit., p. 339. 

 <t Bonney, Volcanoes, London, 1899, p. 226. 

 e Zirkel, Lehrbuoh d. Petrographie, vol. 2, p. 828. 

 /Zirkel, op. cit., pp. 615, 616, 828, 829. 

 orHutton, F. W., cited by Zirkel, op. cit., vol. 2, p. 618. 

 * Ferrer, H. T., Geog. Jonr., Apr., 1905, p. 375. 



