Mesabi Range
Coordinates: 47°30′36″N 93°37′48″W / 47.51000°N 93.63000°W
The Mesabi Iron Range is an elongate trend containing large deposits of iron ore, and the largest of four major iron ranges in the region collectively known as the Iron Range of Minnesota. Discovered in 1866, it is the chief iron ore mining district in the United States. The district is located in northeast Minnesota, largely in Itasca and Saint Louis counties. It was extensively worked in the earlier part of the 20th century. Extraction operations declined throughout the mid-1970s but rebounded in 2005. China's growing demand for iron, along with the falling value of the U.S. dollar versus other world currencies, have made taconite production profitable again, and some mines that had closed have been reopened, while current mines have been expanded.
The Mesabi Range was known to the local Ojibwe as Misaabe-wajiw ("Giant mountain"). Throughout the Mesabi Range, "Mesaba" and "Missabe" spelling variations are found along with places containing "Giant" in their names.
There are three iron ranges in northern Minnesota, the Cuyuna, the Vermilion, and the Mesabi. Most of the world's iron ore, including that contained in northern Minnesota, was formed during the middle Precambrian period. During this period, erosion leveled mountains. This erosion released iron and silica into the waters of a new sea. Marine algae living in this new sea raised the level of atmospheric oxygen. This oxygen catastrophe caused the eroded iron to precipitate into the banded iron formations found in northern Minnesota and other members of the Animikie Group. Over billions of years, geological forces left behind ore deposits of varied quality and concentrations – differences that would determine how the ore was mined from place to place. On the Vermilion Range, between Soudan and Ely, lay the deepest veins of ore. There, miners worked in deep underground mines, blasting the ore from volcanic bedrock. On the Mesabi Range, stretching 100 miles (160 km) from Grand Rapids to Babbitt, soft ore lay close to the surface, where it could be scooped from open pit mines.
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