Useful Minerals

(mineral product), natural mineral formations of inorganic or organic origin in the earth’s crust that can be used efficiently in material production. Useful minerals are classified as solid (coals, ores, nonmetallic minerals), liquid (petroleum, mineral waters), or gaseous (natural combustible gases and inert gases).

Geological conditions of formation and regional characteristics in distribution of deposits. Useful minerals formed throughout the time the earth’s crust was developing as a result of endogenic and exogenic processes. The substances necessary for the formation of minerals are drawn from the upper mantle, crust, and surface of the earth and are present in magmatic melts and liquid and gaseous solutions.

Deposits of magmatic origin, or endogenic deposits, are subdivided into several groups. Magmatic deposits form when magmatic melts are introduced into the earth’s crust and cool. Basic intrusions are linked to ores of Cr, Fe, Ti, Ni, Cu, Co, the group of platinum metals, and other metals; ores of P, Ta, Nb, Zr, and the rare earths are associated with alkaline masses of magmatic rock. Granitic pegmatites are genetically related to deposits of mica, feldspar, precious stones, and ores of Be, Li, Cs, Nb, and Ta; they are also on occasion genetically related to Sn, U, and the rare earths. Carbonatites, which are associated with ultrabas-ic-alkaline rocks, constitute an important type of deposit; they have accumulations of ores of Fe, Cu, Nb, Ta, and rare earths, as well as apatite and micas. Among the useful minerals found in contact-metasomatic deposits, particularly skarns, are ores of Fe, Cu, Co, Pb, Zn, W, Mo, Sn, Be, U, and Au and accumulations of rock crystal, graphite, and boron. Large amounts of useful minerals are concentrated in pneumatolytic and hydro-thermal deposits. The most important are Cu, Ni, Co, Zn, Pb, Bi, Mo, W, Sn, Li, Be, Ta, Nb, As, Sb, Hg, Cd, In, S, Se, Au, Ag, U, Ra, quartz, barite, fluorite, and asbestos.

Deposits of sedimentary origin, which result from exogenic processes, are subdivided into sedimentary, placer, and weathering deposits. Sedimentary deposits form on the bottom of seas, lakes, rivers, and swamps, occurring as sheets within the sedimentary rock that encloses them. Placers, which contain gold, platinum, diamonds, and other valuable minerals, accumulate in the coastal deposits of oceans and seas, in river and lake deposits, and on valley slopes. Weathering deposits are related to the ancient and modern weathering mantles, which are characterized by infiltration deposits of uranium, copper, and native sulfur ores and residual deposits of nickel, iron, manganese, bauxites, magnesite, and kaolin.

At the high pressures and temperatures that prevail deep within the earth, previously existing deposits are transformed and beds of metamorphic origin may develop; examples include the iron ores of the Krivoi Rog Basin and the Kursk Magnetic Anomaly and the gold and uranium ores of South Africa. Alternatively, deposits may be formed anew in the process of meta-morphism, as with deposits of marble, andalusite, kyanite, and graphite.

The scientific basis for the exploration of and prospecting for useful minerals is the study of relationships between deposits of useful minerals, between the main characteristics of a geological structure and the history of the given territory, and between a territory’s geochemical, hydrogeological, and geomorphological characteristics. This research makes it possible to identify the laws governing the location of deposits of useful minerals.

Provinces of useful minerals are large areas that are geographically and geologically distinct and have certain groups of deposits specific to them. The laws governing the location of useful minerals within provinces depend on the region’s affiliation with geosynclines, central continental cratons, and zones of tectonic and magmatic activity. Other factors include the provinces’ geological age, the period in which the minerals were formed, the extent to which the stages of geological development in the given sector of the earth’s crust have manifested themselves, the nature of the provinces’ common rock formations, and the depth of erosion.

Ore provinces are identified by mapping the developmental areas of deposits of a given epoch. They are subdivided into ore areas, which are in turn subdivided into ore regions, which have developed deposits of certain ore formations. The ore regions have ore fields, which are groups of deposits of common origin and geological structure. The ore fields consist of ore deposits, which encompass one or several contiguous ore bodies and can be worked by one mine.

Provinces are classified according to the nature of the rock formations and associated ores. An example is the femic, or Ural-type, province, which has prevalent development of basal-toid magmatic formations and characteristic deposits of ores of Fe, Ti, V, Cr, platinoids, and Cu. In contrast to these are sialic, or Verkhoiansk-type, provinces, with a prevalence of granitoid magmatic formations and related deposits of ores of Sn, W, Be, and Li.

Provinces are sometimes classified according to the combinations of useful mineral deposits they possess and according to the provinces’ geographic location. Examples include the Far Eastern tin province, the Ukrainian graphite province, the Tunguska graphite province, the Kolyma gold province, the lead and zinc province of the Mississippi Valley in the USA, and the Mediterranean bauxite province.

The most important ore provinces correspond to the basic stages of the earth’s geological development and to the metallogenic epochs: the Alpine (internal part of the Pacific Ocean geosynclinal belt, the Mediterranean geosynclinal belt), Kimmerian (external part of the Pacific Ocean geosynclinal belt), Her-cynian (Ural-Mongolian folded geosynclinal belt), Caledonian (Norway, the Zapadnyi Saian), Riphean (southern marginal part of the Siberian Platform), and Proterozoic (Eastern European and Siberian platforms).

Coal provinces include coal basins, regions, and deposits. Petroleum and gas provinces and basins include areas, regions, and zones of petroleum and gas accumulation and deposits of petroleum, gas, or petroleum and gas.

Study of useful minerals. The first ideas concerning the conditions under which useful minerals were formed date back to before the Common Era. In the seventh century B.C., the Greek philosopher Thaïes hypothesized that water was the primary source of everything living and dead. A century later, Heraclitus, and later Zeno, argued that useful minerals formed under the influence of fire. In the Middle Ages, G. Agricola studied the conditions under which useful minerals formed and first classified deposits by the form of bedding. M. V. Lomonosov laid the foundation for the study of the developmental genesis of useful minerals, with the plutonist J. Hutton and the neptunist A. Werner also doing work in this area. Russian geologists who made significant contributions to the geology of useful minerals include D. I. Sokolov, G. E. Shurovskii, K. I. Bogdanovich, and V. A. Obruchev.

In modern times, the different approaches to the study of useful minerals has led to the establishment of a number of major scientific fields. Ore formation has been studied by A. G. Betekhtin, Iu. A. Bilibin, A. N. Zavaritskii, D. S. Korzhinskii, V. M. Kreiter, V. A. Nikolaev, V. I. Smirnov, S. S. Smirnov, and A. E. Fersman. Solid combustible minerals have been studied by A. A. Gapeev, I. I. Gorskii, Iu. A. Zhemchuzhnikov, A. K. Matveev, and P. I. Stepanov. Scientists who have done work in petroleum geology include N. B. Vassoevich, I. M. Gubkin, S. I. Mironov, and M. F. Mirchink. P. M. Tatarinov has engaged in research on the geology of useful nonmetallic minerals.

At the turn of the 20th century, several schools emerged with various theories concerning the formation of useful mineral deposits. W. Lindgren and other geologists -of the American school analyzed geological structures that control the formation and localization of accumulations of useful minerals; they created models to simulate the natural physicochemical conditions under which structures were formed. H. Schneiderhöhn and the German school studied the mineral materials of deposits. L. de Launay, L. Elie de Beaumont, and others in the French school conducted regional analysis of metal content. T. Kato, T. Watanabe, and other representatives of the Japanese school investigated volcanogenic ore formation. Contributions to the geology of coal were made by W. Gothan, H. Potonié, and R. Tiessen. W. Gussow, H. Höfer, and J. White contributed to the geology of petroleum and natural gases.

Current knowledge of useful minerals enables scientists to predict that certain minerals will be found in specific areas. Further research in the theory of the formation of useful minerals is necessary to determine precisely the sources of the matter for these minerals, the forms of migration, the geological and physicochemical parameters of concentration, and the depth of distribution.

Mineral resources. The term “mineral resources” denotes the aggregate of useful minerals found in a state, a continent, or the whole world. Mineral resources serve as the basis for the development of major industrial sectors, including power engineering, ferrous and nonferrous metallurgy, the chemical industry, and construction.

Based on their industrial applications, mineral resources are grouped as follows: (1) fuel and energy resources, including petroleum, natural gas, coal, combustible shales, peat, and uranium ores; (2) ores that are the raw material base for ferrous and nonferrous metallurgy, including iron and manganese ores, chromites, bauxites, and ores of copper, lead-zinc, nickel, tungsten, molybdenum, tin, antimony, and the noble metals; (3) raw materials for the mining and chemical industry, including phosphorites, apatites, common salt, potassium and magnesium salts, sulfur and its compounds, barite, boron ores, bromine, and iodine-containing solutions; (4) natural building materials, the large group of useful nonmetallic minerals, and decorative, industrial, and precious stones, including marble, granite, jasper, agate, rock crystal, garnet, corundum, and diamond; and (5) hydrominerals, including underground fresh and mineral water. This grouping is arbitrary because useful minerals may have various industrial applications. For example, petroleum and gas are not only economical fuels but also important raw materials for the chemical industry.

The quantitative estimate of mineral resources is expressed as identified and explored reserves of useful minerals. The quantity of explored reserves of mineral raw material varies according to the amount of mineral products extracted, the degree of exploration, and growth in explored reserves. It changes with increased geological knowledge concerning the structure of the earth’s crust and possible concentrations of useful minerals in various parts of the crust. Table 1 presents cumulative data on proved and possible reserves of the major types of mineral products as of early 1973 and the amount extracted, by continent, in 1972. Table 2 shows the resources of the major types of mineral products in capitalist and developing countries, according to Mineral Resources of the Industrially Developed Capitalist Countries and the Developing Countries (Moscow, 1974).

The most significant proved reserves of manganese ore are in Gabon, Brazil, the Republic of South Africa, India, and the Commonwealth of Australia; of chromites, in the Republic of South Africa, Rhodesia, Turkey, and the Philippines; of cobalt ores, in Zaire, Zambia, Canada, and New Caledonia; and of tungsten ores, in South Korea, the Commonwealth of Australia,

Bolivia, Portugal, the USA, and Brazil. The most significant proved reserves of molybdenum ores are in the United States, Canada, Chile, and Peru; of mercury ores, in Spain, Italy, Turkey, and Mexico; of antimony ores, in Bolivia, the Republic of South Africa, Turkey, Thailand, and Mexico; of asbestos, in Canada and Rhodesia; of potassium salts, in Canada, the Federal Republic of Germany, the USA, and France; of phosphorites, in the USA, Morocco, Algeria, Tunisia, Peru, and the Commonwealth of Australia; and of native sulfur, in Iraq, Mexico, the USA, Jordan, Japan, and Italy.

Data on the quantity of diamonds and ores of the noble metals extracted in 1972 give some indication of resources: gold, more than 910 tons in the Republic of South Africa, 65 in Canada, 44 in the USA, 23 in Ghana, and 23 in the Commonwealth of Australia; silver, about 1,500 tons in Canada, 1,250 in Peru, 1,160 in Mexico, 1,160 in the USA, and 700 in the Commonwealth of Australia; platinum metals, about 42 tons in the Republic of South Africa and 12.4 in Canada; diamonds, 13.4 million carats in Zaire, 7.4 in the Republic of South Africa, 2.6 in Ghana, 2.4 in Botswana, 2.2 in Angola, 1.8 in Sierra Leone, and 1.6 in Namibia.

Mineral resources are inadequate in many industrially developed countries, including Japan, Great Britain, the Federal Republic of Germany, and France. Even the USA, which is rich in many minerals, must import nickel, manganese, bauxites, tin, tungsten, mica, diamonds, and other minerals.

The socialist countries, especially the USSR, have extensive mineral resources. The Soviet Union leads the world in explored reserves and in the extraction of coal, iron ore, manganese ore, and potassium salts. Among the nations of the world it is first in reserves and second in extraction of natural gas and asbestos, second in extraction of petroleum, and first in reserves, extraction and production of many nonferrous metals, phosphate fertilizers, chromites, and other useful minerals. Approximately 50 percent of the world’s predicted coal resources are concentrated in the USSR: geological reserves of hard coal calculated to a depth of 1,800 m and brown coal calculated to a depth of 600 m are estimated at 6,800 billion tons, more than 260 billion tons of which have been explored and classified in categories A, B, and C₁. Petroleum and natural gas resources are significant. Predicted geological reserves of natural gas exceed 120 trillion cu m, roughly 30 percent of the world total; this includes about 23 trillion cu m of explored reserves, more than 60 percent of which are concentrated in the vast deposits of Tiumen’ Oblast. The USSR has some 40 percent of the world total of explored reserves of iron ores and more than 75 percent of explored world reserves of manganese ores. Total reserves of iron ores in the USSR exceed 100 billion tons, including 60 billion tons of explored reserves. Geologists have identified major reserves of potassium salts, phosphate ores, aluminum, copper, nickel, lead, zinc, tungsten, molybdenum, tin, antimony, rare and noble metals, asbestos, graphite, mica, fluorite, magnesite, sulfur, rock salt, boron ores, and various rocks used in construction. The USSR has become a major exporter of minerals and mineral products, primarily to the other socialist countries.

Deposits of chromites and nickel ores have been found in Albania. Bulgaria has beds of coals and lignites; iron, lead, zinc, and copper ores; and mineral waters. Hungary has significant bauxite reserves and explored deposits of brown coal, lignites, manganese ore, petroleum, and gas. The Socialist Republic of Vietnam has deposits of hard coal, iron ore, apatite, and tin, tungsten, lead, and zinc ores. The German Democratic Republic is a world leader in reserves of brown coals and potassium salts and has deposits of copper ores, fluorite, and lead-zinc and uranium ores. China has large reserves of hard and brown coals and large reserves of ores of iron, tin, mercury, antimony, tungsten, molybdenum, titanium, vanadium, lead, zinc, and silver. The Democratic People’s Republic of Korea has deposits of hard and brown coal and ores of iron, copper, lead, zinc, tungsten, molybdenum, chromium, cobalt, nickel, graphite, and magnesite. Deposits of cobalt, nickel, and copper ores are found in Cuba. Mongolia possesses deposits of hard coal, iron ores, gold, piezoelectric crystal, phosphorites, fluorites, and ores of tin, copper, and other nonferrous metals.

Poland has the Silesian basin of high-quality hard coals, the largest such basin in Europe; there are also deposits of copper ore, native sulfur, lead and zinc, common salt, magnesite, and gypsum. Rumania has significant mineral resources, including deposits of petroleum, gas, coals, lignites, nonferrous metal ores, rock salt, and barite. Czechoslovakia possesses large deposits of hard and brown coals, lignites, magnesite, kaolin, and graphite, as well as deposits of ores of antimony, tin, tungsten, and fluorite. Yugoslavia has large reserves of high-quality bauxites and is a leader in Europe in the extraction of these bauxites; it also possesses significant deposits of mercury, antimony, lead, zinc, copper, iron, magnesite, barite, rock salt, and lignites.

The growth of industrial production in most countries creates a growing demand for mineral resources. Each year the world mining industry increases production 4–8 percent. Between 1951 and 1970 world petroleum extraction increased 4.5 times, natural gas extraction rose more than 5 times, iron ore extraction increased almost 3 times, coal extraction rose 1.6 times, and world cement production increased 3.5 times. During the same period the production of nonferrous metals in the capitalist and developing countries increased 1.6 times for lead, 2.2 times for copper and zinc, 3.9 times for nickel, 5 times for molybdenum, more than 6 times for aluminum, and 9.6 times for magnesium.

In the 1970’s, an average of some 6.5 billion tons of coal, petroleum, and gas (converted to conventional fuel) has been extracted annually throughout the world. It is forecast that by the year 2000, 20–25 billion tons of mineral fuels will be taken from the earth annually. In 1970, about 400 million tons of iron was extracted from ores; by the year 2000, the figure will rise to more than 1 billion tons a year.

Unlike many natural resources, the mineral riches of the earth are not renewable. The problem of using mineral resources as efficiently and fully as possible is therefore becoming increasingly important. This involves, among other things, sharp reductions in losses during extraction and processing. It is essential to extract more than just the basic components when mining complex ores. For example, cobalt, nickel, titanium, vanadium, phosphorus, and other valuable elements can be extracted from many iron ores. Almost all the rare-earth and trace elements needed for new technology do not form independent deposits in nature and can only be obtained by comprehensive processing of nonferrous metal ores. It is economically important to use casinghead petroleum combustible gas and the sulfur and helium contained in the natural gas of many deposits.

The likelihood of discovering new deposits at depths accessible to present-day technology is diminishing. Therefore, the depths at which useful minerals are extracted are increasing, and there is growing exploitation of deposits with lower contents of minerals, including deposits with poor ore or ores that are difficult to concentrate. Useful minerals are now being extracted on an industrial scale from the ocean. Predicted reserves of petroleum and gas are very large, and there is a good deal of interest in the underwater deposits of titanium and tin and the accumulations of ferromagnesian concretions (containing nickel, cobalt, and copper) that are widespread on the floor of the Pacific and Indian oceans. The waters of the world ocean and underground brines have important mineral reserves.

Information on major mineral resources and their distribution is also given in the articles on individual minerals and countries.