Mesabi RangeThe Mesabi Iron Range is a mining district and mountain range in northeastern Minnesota following an elongate trend containing large deposits of iron ore. It is the largest of four major iron ranges in the region collectively known as the Iron Range of Minnesota. First described in 1866, it is the chief iron ore mining district in the United States. The district is located largely in Itasca and Saint Louis counties.
Iron oreIron ores are rocks and minerals from which metalliciron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the form of magnetite (Fe3O4, 72.4% Fe), hematite (Fe2O3, 69.9% Fe), goethite (FeO(OH), 62.9% Fe), limonite (FeO(OH)·n(H2O), 55% Fe), or siderite (FeCO3, 48.2% Fe).
MinnesotaU.S. stateState in the United StatesMinnesota is a state in the Upper Midwestern region of the United States. It is bordered by the Canadian provinces of Manitoba and Ontario to the north and east and by the U.S. states of Wisconsin to the east, Iowa to the south, and North Dakota and South Dakota to the west. The northeast corner has a water boundary with Michigan across Lake Superior.
Sedimentary rockSedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedimentation is any process that causes these particles to settle in place. Geological detritus originates from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes.
Banded iron formationBanded iron formations (BIFs; also called banded ironstone formations) are distinctive units of sedimentary rock consisting of alternating layers of iron oxides and iron-poor chert. They can be up to several hundred meters in thickness and extend laterally for several hundred kilometers. Almost all of these formations are of Precambrian age and are theorized to record the oxygenation of the Earth's oceans.
Newton Horace WinchellNewton Horace Winchell (December 17, 1839 – May 2, 1914) was an American geologist chiefly notable for his six-volume work The Geology of Minnesota: Final Report of the Geological and Natural History Survey of Minnesota, which was prepared by Winchell and his assistants. A bibliography of his publications by Warren Upham in the Bulletin of the Geological Society of America (volume 26, pp. 27–46) contains almost 300 titles.
CarbonateA carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula CO3. The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate groupO=C(−O−)2.
IronChemical element with atomic number 26 (Fe)–↑Fe↓Rumanganese ← iron → cobalt
QuartzQuartz is a hard mineral composed of silica (silicon dioxide). Its atoms are linked in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen atom being shared between two tetrahedra, giving an overall chemical formula of SiO2. Therefore, quartz is classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most common mineral or mineral group in Earth's lithosphere, comprising about 12% by mass.
Taconic orogenyThe Taconic orogeny was a mountain building period that ended 440 million years ago (Ma) and affected most of modern-day New England. A great mountain chain formed from Eastern Canada down through what is now the Piedmont of the east coast of the United States. As the mountain chain eroded during the Silurian and Devonian periods, sediment spread throughout the present-day Appalachians and midcontinental North America.
ChertChert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a chemical precipitate or a diagenetic replacement, as in petrified wood. Where chert occurs in chalk or marl, it is usually called flint.PrecambrianThe Precambrian ( pree-KAM-bree-ən, -KAYM-; pre-Cambrian, or Cryptozoic, sometimes abbreviated pꞒ or PreꞒ) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinized name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time.*As an Amazon Associate I earn from qualifying purchases.