Vol 65 Iss. 2

One of the most characteristic features of the activation zones is the clearly expressed independence of the structural plan of the activation period in relation to the structural plan of the basement. In the territory of the Eastern Transbaikalia, chains of troughs, dike belts, chains of intrusions and volcanic apparatuses associated with Late Mesozoic activation cross the boundaries of the basement blocks having different composition and different geological history.

Many geologists-tectonists, as well as specialists dealing with the issues of general and regional metallogeny, consider it necessary to distinguish a special type of structures of the continental earth crust, different from the platform and geosynclinal structures. However, the volume of such structures, the content and nature of the processes generating them and their place in the general history of development of crustal structures are considered from completely different, often opposite points of view.

When studying hydrothermal deposits, the attention of researchers, first of all, is attracted by vein bodies diverse in composition and structural and textural features. Clarification of conditions and processes of their formation is in this case the main and rather difficult problem.

The Udachnaya kimberlite pipe is located on the southern slope of the Anabar anteclise. The sedimentary section intervening the pipe is represented by carbonate (calcareous-dolomitic) sediments of the Cambrian and Upper Proterozoic with a thickness of up to 4000 m.

The Sokolovskoye magnetite ore deposit is one of the largest in the Turgai Trough. It lies among sedimentary volcanogenic rocks of Lower Carboniferous age (Civ + n), monoclinally falling to the east at angles from 40 to 60°. Structurally, the deposit is confined to the eastern wing of the anticlinal fold.

Tin ores of the Deputatskoye deposit (North-East Yakut ASSR) were formed during five stages: quartz-tourmaline, cassiterite-silicate-quartz, quartz-sulfide, quartz-carbonate-sulfide and carbonate. Cassiterite was isolated from solutions of all stages, but its main mass appeared in the second stage in close association with vein quartz, tourmaline, fluorite, chlorite and wolframite. Cassiterites of the second (main productive) stage were the subject of our study.

Researchers studying the regularities of gold mineralization location within the ore fields or individual ore bodies of deposits of the ubugo-sulfide formation often encounter serious difficulties.

In the practice of predicting mercury deposits does not find proper use of ore-formation criterion, although experiments systematization of mercury deposits on the formation basis has been done repeatedly. This issue is devoted to a number of works by Academician A. Kuznetsov and other researchers.

The study of distribution patterns of impurity elements is a necessary addition to the genetic and industrial characterization of ores and is of particular importance in connection with the problem of their integrated use. In ores of Sarbaisky deposit iron as the leading ore-forming element is accompanied by a significant number of impurity elements, the most important of which is cobalt.

The article deals with the peculiarities of distribution and behavior of manganese in genetically related series of Caledonian granitoids of Northern Kazakhstan, combining three intrusive complexes of Middle-Upper Ordovician-Krykkuduk (granodiorites), Lower Devonian-Borovsky (normal biotite granites) and Middle Devonian-Balkashinsky (leucocratic and alaskite granites).

The deposit is located in the western exocontact of the microcline granite massif and is confined to a brachianticline composed of various crystalline schists. It is necessary to pay attention to the following features of the geologic structure of the birthplace...

Drilling of boreholes in comparison with sinking of mine workings allows to explore placer deposits of minerals with less time and money. The main type of mechanized sinking of exploration wells in gold-bearing placers in the USSR and abroad is percussion drilling.

When comparing the data of exploration and exploitation at the sites of Sarbaisky and Sokolovskoye mining pits, it was found that operational exploration on a network of 50x25 m does not clarify the data of detailed exploration, carried out on a network of 100x50 m. At the same time at the sites of both quarries at detailed and operational exploration slightly underestimated ore reserves and iron content in them.

A striking feature of the Devonian period is the widespread occurrence of reefs, most of which are associated with geosynclinal seas. In character and size, the Devonian reefs present a rather motley picture. The largest reefs are located in the marginal parts of geosynclinal troughs.

The territory of Pavlodar Priirtyshie is confined to the north-eastern part of East Kazakhstan. The Carboniferous and Permian sediments composing it are almost everywhere overlain by a cover of loose Mesozoic and Cenozoic sediments. Therefore, the geological survey and prospecting works carried out here, the purpose of which is to clarify the geological structure to identify minerals, are associated with drilling.

The lithologic-paleophytologic substantiation of the Lower Permian coal-bearing sediments of the Minusinsk basin was made on the basis of a detailed lithologic-facial and paleophytologic description of the section of the Izikhskoye field, where the productive stratum (1750 m thick) is most fully developed and where sediments in the age range from Carboniferous to Permian are traced.

The role of concentrations of dispersed matter in the formation of its micro-component composition was elucidated on the material of 160 samples of insoluble organic matter concentrates obtained by the enrichment method from sediments of different ages and different regions of the Soviet Union.

Paleogene and Neogene coal-bearing in the area of the Dnieper-Donets depression is widely spread. The lithologic and geologic features of the Paleogene-Neogene deposits of the Dnieper-Donets Basin and the peculiarities of the structure of the Paleozoic basement are covered in great detail in the literature.

The stratigraphy of Carboniferous eugeosynclinal coal-bearing deposits of the eastern slope of the Urals, despite more than a century and a half of research, remains poorly studied. For the majority of deposits several stratigraphic schemes have been proposed, differently determining the age of the coal-bearing strata - from Turnean to Visean and even Middle Carboniferous.

The question of the correct determination of the economic efficiency of geological exploration, despite its obvious importance and relevance, has not been finally resolved. In industrial practice for this purpose is used the value of costs per unit of explored mineral reserves, ie, the cost of exploration of a unit of reserves. Е. О. Pogrebitsky economic efficiency of exploration work in percent is defined as the ratio of the cost of exploration to the value of extracted products...