The Kursk Magnetic Anomaly () is recognized as the largest

magnetic anomaly In geophysics, a magnetic anomaly is a local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying ...

on Earth. It is a territory rich in

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 ...

s located within the

Kursk Kursk (, ) is a types of inhabited localities in Russia, city and the administrative center of Kursk Oblast, Russia, located at the confluence of the Kur (Kursk Oblast), Kur, Tuskar, and Seym (river), Seym rivers. It has a population of Kursk ...

, Belgorod, and

Voronezh Voronezh ( ; , ) is a city and the administrative centre of Voronezh Oblast in southwestern Russia straddling the Voronezh River, located from where it flows into the Don River. The city sits on the Southeastern Railway, which connects wes ...

oblasts in

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

, and constitutes a significant part of the Central Black Earth Region. The Kursk Magnetic Anomaly (KMA) was first discovered in 1773 by the Russian astronomer and academic Pyotr Inokhodtsev while preparing the maps of the General Land Survey () at the behest of the Russian government. It was not investigated again until 1874 when I. N. Smirnov conducted the first geomagnetic survey of European Russia. In 1883, N. D. Pilchikov, an assistant professor at Kharkiv University, conducted a series of 71 observations of the Kursk Magnetic Anomaly. These revealed a much larger extent than previously measured and for the first time attributed the anomaly to the presence of iron ore. In 1884, on the basis of this discovery, Pilchikov was awarded the silver medal of the Russian Geographical Society. Serious investigation of the economic potential of the anomaly occurred under the leadership of Ivan Gubkin in 1920–1925, originally based upon the possibilities for oil. Rich ores were discovered in the region of the anomaly about 1931. The ores are spread over an area estimated at and are

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 ...

quartzite Quartzite is a hard, non- foliated metamorphic rock that was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tecton ...

s disseminated throughout metamorphic rocks and

Pre-Cambrian The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, or Cryptozoic) 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 ...

granitoids. Surveyed ore reserves of

ferrous In chemistry, iron(II) refers to the chemical element, element iron in its +2 oxidation number, oxidation state. The adjective ''ferrous'' or the prefix ''ferro-'' is often used to specify such compounds, as in ''ferrous chloride'' for iron(II ...

quartzite are presently estimated at more than of 32–37% Fe and more than of 52–66% Fe. The

open pit Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique that extracts rock or minerals from the earth. Open-pit mines are used when deposits of commercially useful ore or ...

method is used to mine this ore at the Stoylenskoye, Lebedinskoye, and Mikhailovskoye deposits.

Underground mining Mining is the extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a la ...

methods are used for the Korobkovskoye deposit.

References

{{coord, 51, 15, 13, N, 37, 40, 10, E, display=title Exploration geophysics Geology of European Russia Mining in Russia Magnetic anomalies Geography of Kursk Oblast Geography of Belgorod Oblast Geography of Voronezh Oblast

See also

References