Magnetic prospecting is a complex of geophysical methods of exploratory geophysics based on measuring the components of the Earth's magnetic field. The measured value of the magnetic field is its main power characteristic - induction B [T]. In an external magnetic field, geological bodies are magnetized and strengthen the Earth's field, forming anomalies. Some metal ores containing minerals with ferromagnetic properties retain the remanent magnetization obtained in previous geological eras and form especially intense anomalies, well distinguished by modern magnetometers . In particular, they include magnetite , titanomagnetite and others. The nature of magnetic anomalies depends on the geographical coordinates, as well as the differences in rocks in magnetic susceptibility [1] . Magnetic exploration is used to search for iron ore, in geological mapping, in archeology [2] , in ecology.
Content
Varieties of magnetic exploration
Measurements are made on foot, by road, water, but mainly air transport. The aviation version is mainly used for reconnaissance surveys. At the same time, shooting is carried out from aircraft (for example, An-2M ) by aero magnetometers .
Pedestrian magnetic exploration is characterized by high measurement detail, but low productivity. Measurements from cars are quite productive and detailed, but are tied to the road network. Aeromagnetics has tremendous performance and even allows measurements to be made over the sea, but measurements are taken at a certain flight altitude, which has to be corrected. This circumstance is very critical for such a shallow method of geophysics. Measurements on the water have the same drawback - the measurement result has to be linked to the bottom of the reservoir.
Notes
- β Alexander Andreevich Logachev. Magnetic exploration course . - Gos. scientific and technical publishing house of literature on geology and mineral protection, 1955. - 312 p.
- β A. D. Avdusin. Field archeology of the USSR . - Ripol Classic, 1972 .-- 333 p. - ISBN 9785458342100 .
Links
- Logachev A.A. Zakharov V.P. Magnetic exploration. // Leningrad, "Nedra", 1979
See also
- Magnetotelluric sounding
- Magnetic anomaly