maps describing the location or the conditions of formation of mineral deposits. These maps are prepared on the basis of records of mineral deposits and data obtained from geological surveying, prospecting, and exploration. The compilation of these maps often requires special metallogenetic, geochemical, hydrochemical, lithological, and paleogeographic research, as well as study of the conditions of coal accumulation and of the presence of petroleum and gas.
Depending on their purpose, mineral maps may be divided into three groups: registration maps, maps snowing patterns of distribution of minerals, and prospecting maps. In terms of scale, mineral maps may be divided into small-scale maps (1:500, 000 and smaller), medium-scale maps (1:200, 000–1:100, 000), and large-scale maps (1:50, 000–1:25, 000).
Registration mineral maps show the location of deposits on a general geographic or schematic geological base, with a reduced color background. If a systematic geological survey has been made, they are compiled on a full geological base. The mineral deposits are depicted by nonscale signs showing the deposit’s composition, size, and genetic type or any combination of these indicators (for one mineral, for interrelated mineral groups, or for all the minerals of a given territory). These maps are often graphic appendixes to surveys of mineral resources. They are essential not only for indicating the location of mineral raw materials but also for determining the prospects for developing mining, metallurgy, and other industries, as well as transportation and agriculture.
Depending on the type of mineral, its genesis, and the methods of study, maps depicting patterns of distribution are divided into metallogenetic and geochemical maps, coal-accumulation and coal-chemical maps, maps showing the presence of gas and petroleum, maps of halogen and other formations, maps showing the ore content of weathering crusts and placer Shlikh maps, maps relating to hydrogeological research, and prospecting maps.
The metallogenetic maps show the distribution patterns of various ore-bearing areas, ore deposits, and all types of mineralization with respect to various geological factors. Sometimes metallogenetic maps are called minerogenetic maps, although this term is generally applied to maps showing the distribution not only of ores but also of non-ore deposits. Geochemical maps depict the distribution patterns of mineral deposits on the basis of the clarke (background) and increased content of chemical elements and by revealing the most characteristic chemical elements for certain areas (direct and indirect indicators) in rocks, water, and vegetation. Depending on the phase of the dispersion halos, a distinction is made between atmochemical, biochemical, hydrogeochemical, lithochemical, and other geochemical maps. Coal-accumulation maps depict the patterns of the accumulation and distribution of coal and fuel shales in coal-bearing basins, regions, and individual deposits, with respect to lithological and tectonic conditions and metamorphism. Coal-chemical maps are more specialized, providing data on the chemical and production properties of coal, for example, the yield of volatile substances, caking capacity, and ash content. Maps showing the presence of petroleum and gas give the specific features of the tectonic structure of petroleum and gas basins and regions of individual petroleum and gas deposits; they also depict oil-bearing native rock, its collector properties, and indications of hydrocarbon migration.
Mineral maps relating to hydrogeological research include water-supply maps, hydrochemical maps (indicating the chemical composition of natural waters), maps showing the distribution of mineral waters and springs (for balneological purposes), and maps of thermal and industrial waters. Prospecting maps, depicting areas in which minerals may be found, are used as guides in geological exploration.
REFERENCESInstruktsiia po sostavleniiu i podgotovke k izdaniiu geologicheskoi karty ikartypoleznykh iskopaemykh masshtaba 1:1,000, 000. Moscow, 1955.
Instruktsiia po sostavleniiu i podgotovke k izdaniiu geologicheskoi karty masshtaba 1:50, 000. Moscow, 1962.
Instruktsiia po sostavleniiu i podgotovke k izdaniiu geologicheskoi karty i karty poleznykh iskopaemykh masshtaba 1:200, 000. Moscow, 1969.
Osnovnye printsipy sostavleniia, soderzhanie i uslovnye oboznacheniia metallogenicheskikh i prognoznykh kart rudnykh raionov. Moscow, 1964.
Metodicheskie ukazaniia po sostavleniiu kart neftegazonosnosti i uslovnye oboznacheniia k nim. Moscow, 1965.
Karta perspektiv neftegazonosnosti SSSR, masshtab 1:5, 000, 000. Moscow, 1969.
Atlas kart uglenakopleniia na territorii SSSR. Moscow-Leningrad, 1962.
E. T. SHATALOV