Vol 111

Mudflow processes play a very significant role in the formation of channel sediments in mountainous areas.

As is known, the geochemical zonality of primary halos is expressed in changes in the qualitative composition of associations and quantitative ratios of elements - indicators within the zone of mineralization and is one of the most important parameters widely used in prediction and estimation of the scale of hidden mineralization at depth on the basis of geochemical studies.

The theoretical and practical possibility of prospecting for gold occurrences on the basis of direct hydrogeochemical indicators - direct detection of gold in certain quantities in the waters.

The question of the genesis of gold mineralization in black shale strata is still one of the controversial issues in geology. The article proposes a geochemical model of gold-quartz mineralization based on the results of the study of geochemical features of the region.

The study of the degree of mobility of rare and disseminated elements, which are part of such rock-forming minerals-concentrators as biotite and muscovite, is of great importance in the knowledge of endo- and exogenous ore-forming processes.

In terms of lithochemical prospecting Karelia differs from other regions of our country by almost ubiquitous distribution of cover-glacial deposits and peculiar landscapes, in the formation of which the leading role was played by the activity of former continental glaciations.

The Karelian-Kola region is very difficult for prospecting and geochemical prospecting in particular.

The method of partial extraction of metals is applied in the search for deep deposits in two variants: extraction under the action of an active electric field (PEM) and diffusive extraction of metals under the action of electrochemical potentials (PEM-MDI).

The work is devoted to the construction of mathematical models of secondary superimposed geochemical halos.

The method of active plaque is becoming dominant in the methodology of emanation.

Gamma-spectral logging becomes the leading method of studying wells in the search and exploration of radioactive ore deposits and a wide range of other minerals, as well as in the documentation of wells in order to compile and refine the geologic section.

Complex betwe-gamma analysis is used to determine U and Ra in powder samples of nonequilibrium uranium ores.

The weakest link of underwater radiometry, along with a sufficiently developed hardware and methodological base, is the lack of theoretical developments that allow to determine the gamma radiation field in water for ore bodies of various shapes.

The question about the mechanism of radon transfer in rocks and the related question wiht the depth of emanation exposure methods is not completely solved

At X-ray radiometric sampling of ores in natural occurrence or ore mass in transport tanks variable geometric factor is a serious interference.

In the last decade in the search and exploration of deposits of non-ferrous, rare and noble metals intensively develops and finds wide application in the practice of geochemical prospecting X-ray radiometric method of analysis.

Scientific and technological progress in the field of geochemical prospecting for mineral deposits should provide a transition to a fundamentally new type of end results of these works - the issuance of reliable quantitative estimates of the extent of the expected ore-bearing.

For realization of potential possibilities of X-ray radiometric analysis with semiconductor detectors (SCD) it is expedient to use program-controlled measuring technique, in which the basic operations on gathering and processing of the information are carried out under the control of microprocessors or microcomputers.

One of the most important directions of intensification of geochemical prospecting is the use of nuclear-physical, in particular X-ray methods of express analysis of rocks, the main advantage of which is the possibility of obtaining information on the content of elements directly at the site of work with high productivity.

The study of the influence of various interfering factors in X-ray radiometric logging (XRR) of wells has shown that at rare-metal deposits the accuracy and representativeness of XRR results are affected by micro-cavernosity of well walls, the presence of water and anti-vibration lubricant in wells.

Many publications have been devoted to the study of the influence of the grain size of fluorescent mineral on the RRA results. In the majority of works the theoretical analysis of heterogeneous effect is given and analytical dependences for calculation of secondary radiation fluxes from inhomogeneous media are given, and only few authors offer ways to take into account the influence of heterogeneous effect.