The Magnet Cove igneous complex is a small

alkalic Alkalinity (from ) is the capacity of water to resist acidification. It should not be confused with basicity, which is an absolute measurement on the pH scale. Alkalinity is the strength of a buffer solution composed of weak acids and their ...

ring complex A ring dike or ring dyke is an Intrusive rock, intrusive igneous body that is circular, oval or arcuate in plan and has steep contacts. While the widths of ring dikes differ, they can be up to several thousand meters. The most commonly accepted me ...

lying to the west of the town of Magnet Cove in

Hot Spring County, Arkansas Hot Spring County, officially the County of Hot Spring, is a county located in the U.S. state of Arkansas. As of the 2020 census, the population was 33,040. The county seat is Malvern. Established on November 2, 1829, in the Arkansas Territo ...

.Geology of Titanium-Mineral Deposits, Eric R. Force, Geological Society of America, 1991,
Google Books
/ref> It and the adjacent town are so named due to the existence of

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 ...

and the terrain being a

cove A cove is a small bay or coastal inlet. They usually have narrow, restricted entrances, are often circular or oval, and are often situated within a larger bay. Small, narrow, sheltered bays, inlets, creek (tidal), creeks, or recesses in a coast ...

, a basin-shaped valley. The complex is of

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

age, intruded into

Paleozoic The Paleozoic ( , , ; or Palaeozoic) Era is the first of three Era (geology), geological eras of the Phanerozoic Eon. Beginning 538.8 million years ago (Ma), it succeeds the Neoproterozoic (the last era of the Proterozoic Eon) and ends 251.9 Ma a ...

sediments. Mapping was conducted by the geologists Erickson and Blade in 1963. Units within the complex include

carbonatite Carbonatite () is a type of intrusive rock, intrusive or extrusive rock, extrusive igneous rock defined by mineralogic composition consisting of greater than 50% carbonate minerals. Carbonatites may be confused with marble and may require geoche ...

nepheline syenite Nepheline syenite is a holocrystalline Intrusion, plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or pink, and in general appearance they are not unlike granites, but dark green varie ...

phonolite Phonolite is an uncommon shallow intrusive or extrusive rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic (fine-grained) to porphyritic (mixed fine- and coarse-grained). Phonolite is a var ...

, and ijolite. In addition to the magnetite which forms both massive

lodestone Lodestones are naturally magnetization, magnetized pieces of the mineral magnetite. They are naturally occurring magnets, which can attract iron. The property of magnetism was first discovered in Ancient history, antiquity through lodeston ...

and crystals, the complex is strewn with odd and rare minerals, and is the type locality for five mineral species. Over 100 different minerals have been identified from the area.Mindat data and list of minerals
/ref> There are many

titanium Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...

minerals such as

rutile Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer polymorphs of TiO2 are known, including anatase, akaogiite, and brookite. Rutile has one of the highest refractive indices at vis ...

anatase Anatase is a metastable mineral form of titanium dioxide (TiO2) with a Tetragonal crystal system, tetragonal crystal structure. Although colorless or white when pure, anatase in nature is usually a black solid due to impurities. Three other Pol ...

brookite Brookite is the Orthorhombic crystal system, orthorhombic variant of titanium dioxide (TiO2), which occurs in four known natural Polymorphism (materials science), polymorphic forms (minerals with the same composition but different structure). The ...

, and

perovskite Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as , known as the perovskite (stru ...

, as well as some

vanadium Vanadium is a chemical element; it has Symbol (chemistry), symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an ...

mineralization. Some rare-earth-bearing minerals have also been identified. Many companies have mined the area over the last century, including the Diamond Jo Quarry. The complex has developed a unique soil series, Magnet, which has several inches of dark reddish brown loam over reddish brown clay or clay loam. The Magnet is present only over 5000 acres at the complex and a small outlier at Potash Sulphur Springs.

Arkansas Highway 51 Highway 51 (AR 51, Ark. 51, and Hwy. 51) is a designation for two north–south state highways in Southwest Arkansas. One route of begins Highway 53 near Whelen Springs and runs north to US Highway 67 (US 67) in Donaldson. A second ro ...

runs generally east–west through Magnet Cove.

References

External links

American Mineralogist, Volume 14, pages 484-487, 1929Rockhounding Arkansas
(see location 12) Carbonatite occurrences Geology of Arkansas Mesozoic magmatism Mining in Arkansas Volcanoes of Arkansas Diatremes of the United States Ring dikes {{US-geology-stub