The Iron Mountain District, also known as the Iron Springs District, is a large, high-grade

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

depositBullock, K. C., 1970, Iron Deposits of Utah, Utah Geological and Mineral Survey Bulletin 88, 102 pgs. in southwestern

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

, near Cedar City. It is currently in care and maintenance status (not actively producing iron ore) by CML Metals Corporation, a division of Palladon Ventures and Luxor Capital. Previous owners include

Geneva Steel Geneva Steel was a steel mill located in Vineyard, Utah, United States, founded during World War II to enhance national steel output. It operated from December 1944 to November 2001. Its unique name came from a resort that once operated nearby o ...

and U.S. Steel. The district is made of three primary

topographic Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary scienc ...

highs along an approximately 17 mile lineament: Iron Mountain to the southwest, Granite Mountain in the middle, and The Three Peaks in the northwest. Mineralization in this district occurred as rings around the highs as a

skarn Skarns or tactites are coarse-grained metamorphic rocks that form by replacement of carbonate-bearing rocks during regional or contact metamorphism and metasomatism. Skarns may form by metamorphic recrystallization of impure carbonate protoliths, ...

, a replacement of existing

carbonate rock Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO3), and Dolomite (rock), dolomite rock (also kn ...

material with high-grade

iron ore Iron ores are rocks and minerals from which metallic iron 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 f ...

, mostly in the form of high-grade (>50%Fe in places)

magnetite Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a ...

, but also locally

hematite Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . ...

. Minor

pyrite The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue ...

is also present. Hot fluids are sourced from mid-

Tertiary Tertiary (from Latin, meaning 'third' or 'of the third degree/order..') may refer to: * Tertiary period, an obsolete geologic period spanning from 66 to 2.6 million years ago * Tertiary (chemistry), a term describing bonding patterns in organic ch ...

intrusion In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

s, which core all three areas. Magnetite and hematite occur as replacements in the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

around three

Laramide orogeny The Laramide orogeny was a time period of mountain building in western North America, which started in the Late Cretaceous, 80 to 70 million years ago, and ended 55 to 35 million years ago. The exact duration and ages of beginning and end of the o ...

, quartz monzonite porphyry,

laccolith A laccolith is a body of intrusive rock with a dome-shaped upper surface and a level base, fed by a conduit from below. A laccolith forms when magma (molten rock) rising through the Earth's crust begins to spread out horizontally, prying apart ...

s. The iron ore was discovered by a

Mormon Mormons are a religious and cultural group related to Mormonism, the principal branch of the Latter Day Saint movement started by Joseph Smith in upstate New York during the 1820s. After Smith's death in 1844, the movement split into several ...

scouting party in 1849, and furnaces were established in Cedar City in 1852, and then Old Irontown in 1868, to produce

pig iron Pig iron, also known as crude iron, is an intermediate good used by the iron industry in the production of steel. It is developed by smelting iron ore in a blast furnace. Pig iron has a high carbon content, typically 3.8–4.7%, along with si ...

. Total production by 1965 from the district was 72,136,297

long ton The long ton, also known as the imperial ton, displacement ton,Dictionary.com - ''"a unit for measuring the displacement of a vessel, equal to a long ton of 2240 pounds (about 1016 kg) or 35 cu. ft. (1 cu. m) of seawater."'' or British ton, is a ...

s of iron ore. Major areas of iron deposits and their associated mines/pits/ore bodies include: * Iron Mountain **Blowout **Blackhawk **Comstock **Mountain Lion **Tip Top **Pinto **Chesapeake **Excellsior ** Homestake * Granite Mountain **Desert Mound **Queen of the West *Three Peaks

References

External links

* Geography of Iron County, Utah Iron mines in the United States {{mining-stub