Labrador Iron Ore Belt

one of the largest Precambrian iron ore basins in the world, located in Canada. It stretches in a meridional direction for almost the entire length of the Labrador Peninsula, for a distance of more than 1,300 km. Intensive mining of the deposits of the belt was begun after 1950. The first railroad, 575 km long, was built between Schefferville and Sept-Iles in 1954.

The Labrador Iron Ore Belt is situated in the Labrador Trough, which is composed of thick Proterozoic volcanic and sedimentary strata. The ore bodies are taconites and semitaco-nites (ferruginous quartzites) occurring in layers 60–165 m thick and up to hundreds of kilometers long. The rich ores are loose earthy rocks with hematite and goethite; they formed in the Mesozoic period as a result of ground-water leaching the quartz of the taconites. In the northern part of the belt (the west shore of Ungava Bay) metamorphosed medium-grained magnetite and hematite taconites are intensively developed. In the central part the ferruginous rocks are less metamorphosed and the taconites and semitaconites are suitable for dressing. There are more than 25 billion tons of presumed ore reserves, with 30–35 percent average iron content, that are suitable for open-pit mining. Reserves of rich ores with 51–66 percent average iron content amount to more than 700 million tons, and there are potential additional resources of 500 million tons. In the southern part of the belt the rocks and ores are strongly metamorphosed; there are ferruginous quartzites composed of specularite, magnetite, and quartz, with an average iron content of 30–40 percent. Identified and predicted reserves of ferruginous quartzites suitable for dressing are estimated at 20 billion tons.

In 1968 the Carol Lake mining and dressing complex, the largest in Canada, mined 22.4 million tons of ore from which 10 million tons of concentrate was produced. The average annual output at deposits in the Knob Lake-Schefferville region is more than 6 million tons of rich ore. The total geological reserves of the Labrador Iron Ore Belt are estimated at 45.5 billion tons, with more than 7 billion tons of additional potential reserves. Plans and preparations are under way for a significant expansion in mining and the construction of large mining and dressing complexes, principally in the southern part of the belt.