512 F.H. Hatch— The Iron Ore Supplies of the World. 



It will be seen that in comparison with recent estimates, the 

 Stockholm report OMer-estimated the Lake Superior area, but did not 

 attribute sufficient importance to the remaining areas. Neither 

 estimate includes any of the very low-grade red or Clinton ores, or 

 of the low-grade siliceous ores of the Lake District, of both of which 

 there are enormous quantities. 



Brazil. 



One of the greatest ore reserves of the world, and certainly the 

 greatest reserve of ore suitable for the acid Bessemer process, is 

 situated in the province of Minas Geraes, in Brazil. 



The ores are haematite and magnetite, and occur in rocks similar 

 to the banded jasper of North America and South Africa. They vary 

 in grade, but the average iron content is over 60 per cent, and the 

 phosphorus is in the main well below the Bessemer limit. A pro- 

 portion of the ore occurs in thin lamellae between siliceous layers, but 

 there are large masses of practically pure oxide, like that of Iron Ore 

 Peak (Itabira do Campo) and the Caue deposit of Itabira do Matto 

 Dentro, which is estimated to contain 80 million tons of the highest 

 quality ore. E.G. Harder states that the largest deposit contains at 

 least 350 million tons, and that there are numerous ore-bodies of from 

 10 to 50 million tons. Their possible aggregate tonnage is enormous, 

 but with the present means of transportation the greater portion is 

 inaccessible. Before the War capital was being found to develop 

 these fields and to provide transportation, and it cannot be long 

 before such valuable deposits will be utilized in the world's markets. 

 The ore will probably be exported in great quantity to British and 

 American Bessemer furnaces. 



The economically important ores of Minas Geraes are usually 

 divided into (a) Bedded or Quarry Ores, consisting of (1) thick bedded 

 massive hematite, and (2) thinly bedded siliceous hematite 

 (" jacutinga ") : (&) Fragmental Ores, consisting of (1) rubble ore (a 

 denudation product of the bedded ores), and (2) Canga (recemented 

 rubble). 



The massive ore beds vary in thickness from less than a foot to 

 more than 300 feet, but they are less extensive than the jacutinga 

 ores. Leith and Harder state that single lenses of jacutinga are 

 known more than 3 miles in length and up to 2,000 feet in thickness. 

 Of the high grade massive haematite and jacutinga, ranging in iron 

 content from 63 to 69 per cent, the tonnage was stated by Leith, in 

 1911, to be probably not far short of the total reserves of the Lake 

 Superior district available at that date. The Canga and rubble ores 

 are of lower grade ; even these probably average 50 per cent in 

 iron, but the phosphorus is higher than in the bedded ores. 



Estimates of the total available reserves in the Minas Geraes field 

 vary from the conservative estimate of 2,000 million tons made by 

 Dr. Derby for the Stockholm Report, up to recent estimates of 

 3,500 millions. For the whole iron ore region of Brazil, Merriam 



