Although uranium occurrences are widespread in Mongolia, minable or potentially economic deposits are restricted to date to the North Choibalsan region (Mardai/Dornod District, referred to as Mardai in Mongolian and Dornod (or Dornot) in Russian papers) in NE Mongolia and to the Gobi Desert in S Mongolia (e.g. Choir, Khairkan, Undurshil, Sainshand Basins) (Note: data given for U deposits in Mongolia are based on 1995 status unless otherwise cited). Deposits in these two regions are of volcanic and sandstone type, respectively.

Precambrian mineral deposits are now becoming more significant in the mineral-raw materials balance for many countries in the world, since the vast majority of ores of iron, titanium, vanadium, gold and uranium, non-metals such as muscovite and phlogopite, and considerable amounts of asbestos and barite are currently being worked from Precambrian deposits. Recently, new types of gold, rare-metal, tungsten, tin, beryllium, rare-earth, radioactive elements, platinoids and manganese ore bodies have been discovered, as well as deposits of unusual geochemical associations such as Ni-U, U-Cu-Au and Pt-Au.

The history of mining is replete with controversy, but in recent decades there has been increasing pressure to improve the environmental performance of mining operations, following from greater awareness of global environmental issues. Although Rachel Carson’s 1962 ground breaking text, ‘The Silent Spring’, focused on pesticide damage, it brought attention for the fi rst time to the worldwide scale of environmental degradation associated with the development of an industrial civilization. This introductory chapter will examine the many facets of the relationship between mining and the environment which follow from the demands of that civilization.

Uranium deposits and major occurrences have been reported in nine regions and some isolated locations (>Fig. 6.1). Deposits with resource estimates and mining potential are known from six regions: Kokshetau (Kokchetav), N Kazakhstan, Pricaspian, SW Kazakhstan, Chu-Sarysu Basin, south-central Kazakhstan, Syr-Darya Basin, S Kazakhstan, Pribalkhash or KendyktasChuily-Betpak Dala region, SE Kazakhstan, and Ily Basin, SE Kazakhstan. Deposits of limited economic interest are known from the Turga-Priyrtish region, N Kazakhstan, and the Granitnoye and Zhalanshiksky regions in central Kazakhstan.Principal types of uranium deposits include sandstone, veinstockwork, volcanic stockwork, lignite/coal and a special variety of organic phosphorite-type, viz. clay-hosted phosphatized fossil fi sh bone.

Metal deposits in sedimentary rocks are frequently of controversial origin. This being so, any new approach that has bearing on the genesis of ores in sediments is important. Both epigenetic and syngenetic theories have been invoked for most stratabound deposits. Also, the relative importance of normal sedimentary processes and unusual processes, such as volcanogenic exhalations, has been debated at length. Trace- or minor-element studies of most types of metal deposit have been undertaken by a number of geologists with varying success. This paper reviews some of the more recent geochemical work on certain classes of ores in sediments and relates the geochemical data to the prevalent theories of origin of the deposits.  <...>

The significance of manganese ores is very weil known in cast iron and steel production, as weil as in various types of chemical raw material and agricultural fertilizers. The world industry development in recent years requires their increased production in the vicinity of the metallurgical centers in different regions of the world; high grade manganese and associated metalores are needed. Analysis of the world production and consumption of manganese ores by industrial countries indicates convincingly that the highest commercial value belongs to the ores associated with the supergene zone (National Minerals Advisory Board, 1981;

The mountains and deserts of the West still hold the picturesque ruins of abandoned mines. The boarded tunnels, rough-hewn buildings, immense piles of yellow tailings, and narrow headframes that reach upward to the sky stand as silent witnesses to the vitality of men who once wrested minerals from the earth. But there are few ruins to remind a passerby of the smelters that bought the ores, reduced them to bullion and matte, and then drew out the gold, silver, copper, lead, and other metals. Here you might see bushes growing through a stone foundation; there you might note a mound of black slag. Here you might glimpse a small chimney rising amid the aspen; there you might notice a towering smokestack still piercing the western sky. But little else remains. The wreckers left few reminders of this industry that rose, flourished, and died in symbiosis with the mines. <...>

The paper discusses the results of studying the contents of platinum group elements (PGE) and platinum group minerals (PGM) in ores of the Kingash deposit. The bulk of PGE has been established as concentrated in disseminated sulfide chalcopyrite–pyrrhotite–pentlandite ore and is represented by palladium bismuth–tellurides. During melt differentiation, the content and relationship of PGE are changed; the Pd/Pt value increases (up to 1.9 and 4.2 in dunite and wehrlite, respectively) with decreasing Mg number.

The deposit is situated in southeastern New South Wales at Lat.35°04*S, Long.1A9°34*E. (Fig.l) The first phase of testing proved up a body of poljmietallic massive sulphides and an adjacent zone of dominantly copper ore. The massive sulphides body consisted of about 6.3 million tonnes of copper, lead and zinc ore (1.7% Cu: 5.5% Pb; 14.4% Zn) and was the main target for geophysical investigation. The copper ore zone contains about 3.7 million tonnes averaging about 1.9% Cu, 0.1%Pb, 0.5% Zn in a number of ore shoots both along strike from and below the massive sulphides. Subsequent drilling indicated several concealed bodies of massive sulphides, separate from the first discovered body but these are at depths of more than 200m and hence too deep to have influenced the geophysical investigations.  <...>