EA032161B1 - Geochemical method for searching mineral resource deposits - Google Patents

Abstract

The invention relates to the field of applied geochemistry and could be used in searching mineral resource deposits, in predictive-geochemical mapping of enclosed and semienclosed territories on the basis of data from geochemical mapping territories being investigated and following analyzing samples of soil. The positive result is achieved by congesting the sample net density (especially in searching small and middle gold ore objects), picking samples weighing 50-60 g from the horizon B1; from each picked sample, a suspension is prepared, and from that suspension, a superfine fraction weighing 2-3 g and 2-35 μm in size is extracted and dried at a room temperature for not less than 24 hours. The dried superfine fraction is applied on a glass palette made in the form of plane table with dimensions of 12×10×0.3 cm in number not less than 200 squares; the obtained dry superfine sample fractions are placed into those squares and analyzed for rare and dispersed elements by the method of laser ablation; whereupon, in accordance with content of chemical elements in those fractions, maps of distribution of those elements in area are drawn, zones of anomaly contents of indicator elements are revealed on those maps, and the presence of ore mineralization zones, ore bodies and rare element deposits based on the revealed zones are determined based on the revealed zones.

Description

The invention relates to the field of applied geochemistry and can be used in the search for mineral deposits, in prognostic-geochemical mapping of closed and semi-closed territories based on geochemical mapping of the studied territories and subsequent analysis of soil samples. A positive result is achieved by thickening the sampling network (especially when searching for small and medium-sized gold ore objects), by sampling soil horizon B1 weighing 50-60 g, from which a suspension is prepared and a fine fraction with a particle size of 2-35 microns and a weight of 2-3 g, which is dried at room temperature for at least 24 hours. The dry fine fraction is applied to a glass palette of 12x10x0.3 cm in an amount of at least 200 squares, and the obtained dry fine fractions of samples are analyzed in them, which analyze rare elements by laser ablation, then by the content of the chemical elements build their distribution maps in area and reveal zone on maps of abnormal contents indicator elements, which detect the presence of areas of mineralization of deposits of ore bodies and trace elements.

The invention relates to the field of applied geochemistry and can be used in the search for mineral deposits, in prognostic-geochemical mapping of closed and semi-closed territories based on geochemical mapping of the studied territories and subsequent analysis of soil samples.

Known methods for the search for mineral deposits [1-3]. All these methods, based on the statistical processing of data of elemental analysis of a large array of samples taken over a given network, are widely used to establish the presence, nature and parameters of secondary lithochemical halos and scattering flows of ore bodies, deposits or geochemical specialized rocks from the detected change in the contents of the determined elements in samples. The migration of elements that occurs during the destruction of deposits in the hypergenesis zone can take many forms: the elements can migrate in a solid, liquid, and gaseous state. As a result, scattering halos are formed around the deposits, within which the content of one or another element of interest will, as a rule, be the highest near the deposit and gradually decrease to the side of it.

Known methods for finding deposits by water halos of dispersion of elements based on the analysis of samples of natural waters. The chemical composition of the water to a large extent depends on the composition of the rocks and ore masses through which these waters circulate. Theoretically, water halos can have a large extent, but in practice they can hardly be found at a great distance from the deposits, since when moving through different rocks composing the area, the water will continuously change its composition [4-6]. Elements carried out by aqueous solutions from mineral deposits can be sorbed by highly dispersed mineral and organic products composing the surface of the earth's crust. In this way, sorption halos are formed that occur wherever groundwater comes to the surface and encounters colloidal precipitates capable of sorbing the ions present in the solution.

Known methods for the search for mineral deposits by the so-called mechanical (lithochemical) halos and scattering fluxes that are not offset or slightly offset from the root source. These include the widely known clastic-river and boulder-glacier methods. Till lithochemical survey is based on the fact that minerals enclosed among strong debris and boulders can be transported by river waters and glaciers over long distances [7-10]. However, the known search method is not applicable to deep-lying ore bodies, as well as to deposits for which there are no conditions for the mechanical transfer of minerals of the desired elements, or if these elements do not form their own mineral forms at all, i.e. are in a diffuse state.

The essence of the known methods [11-15] lies in the fact that soil samples, near-surface soil-forming loose deposits or bottom sediments of constant water courses from a depth of 10-20 cm are taken on a given network on a given network. The samples are dried, sieved through a 0.5-1 sieve mm The separated fraction of solid particles is mechanically abraded to the size of analytical powder (0.074 mm) and analyzed by emission spectral analysis or X-ray fluorescence method to determine the content of mineralization indicator elements. By the anomalous contents of indicator elements, secondary lithochemical halos and scattering fluxes are revealed, which predict the presence of ore bodies and deposits. The disadvantage of these methods is the low efficiency when used in closed and half-closed areas, where bedrock is covered by a cover of loose deposits. Under such conditions, mechanical halos and scattering fluxes may be absent in the layer of loose deposits, and sorption-salt halos and scattering fluxes in the solid fraction of particles with a size of 0.5-1 mm may be weakly manifested and not create geochemical anomalies, which will not allow ore ore to be detected. zones, bodies or deposits. The analysis methods used are not sensitive enough to determine the low contents of rare elements.

Quite often, various types of leaching are used in geochemical search methods for the selective extraction of elements [16-19].

For samples enriched with organics, sodium pyrophosphate leaching is used; when using hydroxylamine (hot and cold leaching), most oxides of manganese and iron are dissolved, oxalic acid dissolves all oxide formations and partially weak silicates, a mixture of potassium iodide and ascorbic acid - oxide formations of iron, manganese and aluminum. Water extraction (hot and cold) is used either for preliminary washing of the sample, or for determination of water-soluble salts, extraction with hydrochloric acid - acid-soluble components (with a small sample weight, the concentrations of most elements are below the detection limit).

Not always the method of selective extraction of various salts allows you to get the general picture of the spread of a wide range of chemical elements in the framework of one type of analysis. When using aggressive reagents (acids), the selectivity of the extraction of elements decreases, and due to the high background contents of metals in leaching solutions and high detection limits, weak anomalies can be masked. None of this kind of leaching is selective with respect to rare and dispersed elements, therefore, it does not lead to higher

- 1 032161 sensitivity analysis and, as a result, the identification of contrasting anomalies of rare elements.

There is a known geochemical method for searching for mineral deposits [20], which is closest to the proposed invention in terms of technical solution and technical result, based on the analysis of the ultrafine fraction (MASF - the method of analysis of the ultrafine fraction), adopted as a prototype. The method includes sampling soil (250-300 g), extracting ultrafine fractions (<10 μm) from soil samples and loose deposits by dusting at a plant developed and constructed by VSEGEI. It is assumed that ore particles and indicator elements in a specific mobile form are secondarily fixed on the particles of the sample. Next, a 100 mg sample was treated with aqua regia, and the resulting salts were dissolved in nitric acid. The resulting solution was analyzed on 25 chemical elements [21] by inductively coupled plasma mass spectrometry (ICP MS).

The disadvantages of this method are the uncontrolled size of the particles to be recovered, the need to decompose solid samples and transfer them to a solution using strong acids, the length of time for obtaining analytical data, and the harmful work of personnel. This approach does not allow to obtain contrasting anomalies and, as a result, the accuracy of the method for detecting anomalous zones is low.

Thus, the low accuracy of detecting anomalous zones is due to the uncontrolled size of the extracted particles;

the use of strong acids during decomposition, which leads to inaccurate analysis due to inaccurate operation of the device, for which, according to the instructions, the concentration in the solution, for example HC1, should not exceed 12%;

the duration of obtaining analytical data due to the need for decomposition of samples;

harmful work of staff;

the high cost of a full analysis cycle, which includes the cost of disposal of strong acids.

The proposed method for isolating the finely dispersed fraction does not involve fixing the particle size. The particle size of the fine fraction can vary significantly depending on the natural composition of the sample. In this case, the degree of solubility of the sample, as a function of particle size, will introduce some uncertainty in the interpretation of data with respect to anomalous values. In addition, incomplete extraction of the salt forms of rare elements can occur, since, in contrast to ions, there is no reliable evidence that they are sorbed by particles of a finely dispersed fraction larger than themselves.

A number of preparatory operations for the extraction of the finely dispersed fraction, the process of transferring solid particles into solution, as a whole, requires a significant investment of time and human resource.

When the ultrafine fraction is transferred to the solution when preparing samples for analysis by ICP MS method, strong acids are used (for example, aqua regia), as a result of which not only the sorbed salt forms of the elements pass into the solution, but the rock matrix (carrier) is partially dissolved, and the contribution of the latter to the total element concentration may be predominant.

The inductively coupled plasma mass spectrometry method used after dissolving the sample has limitations on the content of chlorine in solutions, which inevitably prevails in the solution due to the use of hydrochloric acid. At high chlorine contents in solutions, corrections have to be made, which affects the accuracy of the analysis.

When working with strong acids, personnel are required to take increased safety measures. Recycling used acids also requires time and money.

As a result, the method of geochemical searches of rare and dispersed chemical elements in the prototype, based on the method of analysis of the ultrafine fraction (MASF), does not allow us to obtain clear and objective data on their distribution of rare elements in the study area.

These circumstances do not make it possible to accurately localize the position of the field, which requires additional costs for updating data on the identification of anomalous zones in the territory of the survey.

The technical result of the claimed invention consists in increasing the accuracy, reliability and reliability of determining the contents of rare and scattered chemical elements in the study area, increasing the contrast of anomalous zones, and as a consequence of the accuracy of localization of anomalous zones, i.e. a high degree of localization of the anomaly. In addition, the technical result of the claimed method is to save analysis time (express analysis) and analysis cost (cheapness of the method), as well as the safety of personnel.

Controllability of the particle size is achieved due to the use of the Stokes law when choosing the conditions for their extraction with water. The time required to analyze one sample is significantly reduced, which affects the cost of analysis.

The absence of strong acids in the sample preparation scheme makes it possible to maximize the possibilities of the ICP MS method. The staff does not work with strong acids, which reduces the harmfulness of the analysis. There is no need to dispose of acids after use.

In the claimed method, the specified technical result is achieved by taking into account and using

- 2 032161 uses the modern level of scientific achievements in the field of studying the forms of finding chemical elements and the modern capabilities of analytical equipment. An in-depth study of the behavior of chemical elements in a scattering state is an important component in the development of geochemical methods for searching for minerals, especially in the case of searching for deposits of rare and dispersed chemical elements. Research in this area involves working at extremely low levels of concentration, which is limited by the capabilities of the analytical technique.

The formation of innovative methods of geochemical prospecting dates back to the late 90s of the last century, and the possibility of such studies is due to the emergence of modern analytical methods and instruments [22–25].

The transition of geochemical research to the modern level was facilitated by the development of the theory of mobile and secondary fixed forms of elements. Modern search methods are based on the fixation of mobile forms of chemical elements and on their ability to migrate over pores and microcracks of rocks over sufficiently large distances from a deep-lying ore body to the earth's surface.

Taking into account the forms of the presence of trace elements in soils and rocks is important for both geochemists and analytical chemists. A significant part of the chemical elements enter the minerals as isomorphic impurities, replacing the macrocomponents in the crystal lattice. Some of them accumulate in gas-liquid inclusions, and some are in colloidal-dispersed form in the pore space of the rock.

Traditional analytical methods of analysis, such as X-ray spectral, have high sensitivity thresholds for rare and scattered elements (especially gold), which is why it is impossible to identify anomalies of these elements in soils.

Currently, to obtain objective data with the required accuracy and reproducibility, quantitative methods are used to achieve low detection limits, which primarily include atomic absorption spectroscopy (AAS), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and inductively coupled plasma mass spectrometry (ICP-MS). However, their distribution in routine exploratory geochemical methods is limited by the high cost of analysis. In addition, the use of various reagents for opening samples and transferring them to the solution often leads to errors associated with the uncontrolled interfering effect of the solution components and solvents, the content of which is many times higher than the concentration of rare and dispersed elements. This effect leads to an increase in the detection limits of the method, so that the content of the desired elements is lower than the attainable limits.

As a solution to the problem, a method was developed - multielement analysis of the fine soil fraction using laser ablation and an inductively coupled plasma mass spectrometer (BLUR M8).

The essence of the claimed method is that a positive result is achieved by thickening the sampling network (at least 1000 samples per 1 km ² ), which is especially important when searching for small and medium-sized gold ore objects. Sampling weighing 50-60 g is carried out from the upper layer of the illuvial horizon B1, a suspension based on water is prepared from each of the selected samples in a ratio of 1:10, after which a fine fraction weighing 2-3 g and size is isolated from each suspension for 1 min particles of 2-35 μm, dried at room temperature for at least 24 hours and put each of them on a glass palette made in the form of a tablet measuring 12x10x0.3 cm with a square marking of 5x5 mm in an amount of at least 200 squares, place the obtained dry fine particles in them frac and samples which were analyzed in rare elements by laser ablation (blur M8) when the burn area 5x5 mm.

According to the analysis results, anomalous zones are identified and a conclusion is made about the presence of rare and scattered elements at the depth of the deposit. The claimed method differs from the prototype:

a) the size of the testing network. At present, the discovery of small deposits is most likely, and the effectiveness of prospecting for gold and other rare elements substantially depends on the number of geochemical samples taken and analyzed. For this, sampling must be carried out on a dense network exceeding the size of the network specified in the instructions [9]. The number of samples taken for one object is calculated at the rate of 1000 samples per 1 km ² ;

b) small (50-60 g) samples are taken instead of 200-300 g samples.

c) horizon B is being tested as the most informative in terms of the accumulation of chemical elements;

d) the original sample preparation can be carried out in the field, as a result of which the weight of the sample is reduced to 2-3 g, which is important when transporting from remote areas;

d) the analysis of the samples is performed on the instrumental complex BL-YUR M8. Ablation modes: beam speed 900 μm / s; piercing depth 5 microns; energy 65%; frequency 10 Ηζ; beam size 610 microns; piercing time 18 s for gold and 32-60 s for other elements.

- 3 032161

Quality control is carried out using standards and also includes control in an external laboratory. Based on the obtained analytical data, maps of the distribution of the contents of chemical elements are constructed and zones of anomalous contents of indicator elements are identified. Based on the identified zones of abnormal contents of chemical elements, the presence of the required zones of ore mineralization, ore bodies and deposits is judged.

The claimed method was developed theoretically, tested in the field laboratory M1pega1 Exp1oga! ZhCHmogk (Ejapb) L1d in the village of Ollola (Finland) and at the laboratories of St. Petersburg State University, and then in the field in various landscape and climatic zones in Finland and Spain. Analysis control was carried out in certified laboratories in Finland, Spain and Russia.

Samples of the soil horizon from the upper part of the illuvial horizon (B1) are taken over a 50x5 m network. A fine fraction is extracted from the soil sample and analyzed by laser ablation (EA1СР М8) for the content of a wide range of chemical elements (Au, Pk Rd, Ke, Ad, Mo, 8n, Co, N1, Τι, Ζγ, N6, Ta, 8b, Kb, 8e, Υ, Kee, Cr, Mn, Cu, Ζη, Az, Nd, Pb, Cd, 8g, Ba).

Of greatest interest are data on the gold content as one of the most important strategic elements of any state. In the fine soil fraction (TFP), an average gold content of 0.2 g / t was recorded with a background content of 0.004 g / t. Identified anomalies of rare elements are verified by geophysical data.

The geochemical method of searching for mineral deposits by the fine soil fraction was applied, for example, within the Logrosan region (Spain) over an area of 67 km ² . The group of anomalies is represented by two parallel shale zones of a total length of more than 10 km with a power in blow up to 200 m. In order to establish the source of anomalies, 4 profiles of exploratory wells were completed. Wells revealed zones of quartz-sericite metasomatites from sedimentary-metamorphic rocks with a gold content of 0.1-0.4 g / t.

The results of numerous testing with the expected technical result are given in the form of specific examples.

Example 1 demonstrates the informativeness of the analysis of DFT in comparison with the analysis of the soil as a whole.

Each sample of soil horizon B1 with a total mass of 150 g was divided into 2 unequal parts (50 and 100 g). Extraction and analysis of DFT was performed as described above. For comparison, the second part of the soil sample was analyzed by atomic absorption during decomposition according to the standard method with full acid digestion. The analysis data are presented in table. one.

Table 1

The content of Au, Pk Ρά in samples of soil horizon B1 and their fine fractions, ppm

№№ samples Ai P1 Ρά the soil Tfp the soil Tfp the soil Tfp one 0.0085 0.33 <0.004 0.51 <0.004 0.18 2 0.004 0.22 0,03 0.39 0,077 0.19 3 <0,0002 0.13 <0.004 0.31 0,03 0.42 four <0,0002 0.04 <0.004 0.36 0.016 0.2 five 0,0006 0,07 <0.004 0.53 0.08 0.1 6 0.0036 0.35 0.05 0.24 0.08 0.98 7 <0,0002 0.05 <0.004 0.46 0,033 0.6 eight <0,0002 0.009 <0.004 0.42 0.06 0.19 9 <0,0002 0.008 <0.004 0.01 0.13 0.7 ten <0,0002 0,066 <0.004 0,079 <0.004 0.01

The data presented indicate a significant accumulation of precious metals in the fine fraction of the soil compared with the soil as a whole. Due to the accumulation of rare and scattered elements in the TFE, their content is several orders of magnitude higher than in the original soil sample, i.e. in samples in which the content of an individual element is below the detection limit, in DFT is defined as a real value. An analysis of DFT allows one to identify real anomalies, rather than obtain values below the detection threshold, which does not allow for geochemical mapping and construction of distribution maps for the contents of chemical elements.

Example 2. The choice of soil horizon for geochemical testing.

An important point in the search is to establish the soil horizon, which is the most informative when conducting testing. It is important to establish in what horizon the accumulation of indicator elements for the search for chemical elements takes place and in the future to conduct a survey along this horizon. For this, soil sections are laid and they are tested along the section. The results of the study are given in table. 2 and 3.

- 4 032161

table 2

Gold content in different horizons of the soil section, ppm

Soil horizon Gold content Section 1 Section 2 Section 3 BUT 0.01 <0.002 <0.002 IN 1 0.55 0.06 0.009 AT 2 0.22 0.009 0.007

A - humus horizon,

B1 is the upper part of the illuvial horizon, B2 is the lower part of the illuvial horizon.

Table 3

The content of chemical elements in different horizons of the soil section, ppm

E-t Section 1 Section 2 Section 3 Mountains BUT Γορ.ΒΙ City B2 Mountains BUT Γορ.ΒΙ City B2 Mountains BUT Γορ.ΒΙ City B2 Τΐ 2520 2493 2483 1604 4155 4619 1893 4344 3394 V 150 200 180 150 331 210 150 335 180 Mp 162 224 239 41 408 412 144 524 438 With 71 190 155 58 386 372 79 536 254 Si 20 71 24 15 35 21 15 25 18 Ζη 14 52 28 9 63 45 14 58 49 Az 6 15 ten five 63 45 27 437 235 Pb eight 18 eleven 9 15 ten ten 21 five B 35 55 52 32 46 51 21 35 32 8g 160 227 221 181 205 210 152 196 175

A - humus horizon,

B1 is the upper part of the illuvial horizon, B2 is the lower part of the illuvial horizon.

Thus, it was found that the most informative horizon is horizon B1, in which gold and satellite elements accumulate.

Example 3 shows the choice of time for the deposition of DSP during the extraction process.

Selecting the most optimal time period allows you to optimize the time spent on the process.

g of a reference sample with a known gold content and particle size of 0.074 ccm was mixed with 50 g of silica silt-sandstone, which is similar in composition to the soil horizon B1. Were prepared standards with gold contents of 0.005; 0.012; 0.04 ppm. The elutriation was carried out in a glass dish according to the standard procedure from a suspension based on water in a ratio of 1:10, which ensures the implementation of the Stokes law. The results are presented in table. four.

Table 4

The gold content in the fine fraction, depending on the deposition time, ppm

The gold content in the standards, rt 15 minutes 1 minute 0.5 min 0, 005 0, 005 0, 005 less than 0,001 0.012 0.012 0.012 0.010 0, 040 0, 040 0,040 0, 020

The results of the studies in the example show that 1 min is sufficient for precipitation. When using a shorter time interval, we do not get a reliable result, and a longer time interval lengthens the experiment time, but does not affect the analysis result.

Example 4 allows you to evaluate the possibility of using water of varying degrees of purification when isolating a fine soil fraction (TFP).

As mentioned above, when conducting geochemical searches, time and material costs are of great importance. Less expensive (in time and money) methods are preferred.

Since the separation of TPP is carried out in an aqueous medium, it is important to assess what quality water can be used in the separation of a fraction. The results are presented in table. five.

Table 5

An experiment on the extraction of TPP with water of varying degrees of purification

The gold content in the standards, rt Double-distilled water, deionized Water distillate Drinking water from a water supply system 0, 005 0, 005 0, 005 0.012 0.012 0.012 0, 040 0, 040 0, 040

- 5 032161

In the experiments, tap, distilled and bidistilled deionized water was used. The table shows the results of an experiment to analyze reference samples with a gold content of 0.005; 0.012 and 0.04 ppm. It follows from the experiment that the quality of water treatment does not affect the results of the analysis for gold, and thus, tap water can be used in geochemical searches. The result indicates the absence of significant gold contents in tap water.

Example 5 demonstrates the results of an experiment on the selection of the analysis area using the BA-1СР М8 method, which the probe burns during sampling (Table 6).

Table 6

The choice of the analysis area using the BA-1SR M8

Analysis Area (probe) The gold content in the standards, rt Reference 0.005 Standard 0.012 Standard 0.04 Point, 1km 0.003 0.008 0.02 Area 1x1 mm 0.003 0.010 0,032 2x2 mm area 0.004 0.012 0,033 Area 5x5 mm 0.005 0.012 0,040

Thus, it was experimentally established that to obtain correct results, a burn-out area of 5x5 mm can be used.

Example 6 demonstrates the convergence of the results of the analysis of gold in TPPs by laser ablation and control performed by the atomic absorption method in an external laboratory (Table 7). External control is a prerequisite for checking the adequacy of the analysis results in the development of new methods.

Table 7

The results of the analysis of gold in TFE by the claimed method and atomic absorption in an external laboratory, ppt

No. of samples Analysis of gold in TFE by the claimed method Analysis of gold in DFT by atomic absorption in an external laboratory one 2 3 one 85.1 83.3 2 98.9 101.0 3 95.9 95.3 four 86.3 84.7 five 83.9 84.8 6 0.55 0.56 7 0.34 0.38 eight 0.12 0.11 9 0.22 0.24 ten 0.01 0.01 eleven 0.09 0.08 12 0.06 0.06 13 0.05 0.06

The data presented indicate good convergence of the results of DFT analysis by the claimed method and the atomic absorption method performed in an external laboratory.

Thus, summarizing the advantages of the proposed method, the following should be noted: high sensitivity analysis; high reliability, convergence and comparability of the analysis results; high work efficiency (up to 400 samples per day); low cost of work (about 4 euros / sample). Isolation of DFT does not require special conditions for sample preparation and can be carried out in the field. The presented method is an environmentally friendly method, because in the process of sample preparation and analysis, no chemicals are used.

The claimed method for the search for deposits based on the analysis of the fine fraction of the soil, in addition to increasing the reliability and reliability of the search result, allows obtaining reliable information at ultra-low levels of contents, which leads to a significant increase in the likelihood of identifying and reliability of the assessment of anomalous geochemical systems while reducing the cost of analytical work.

List of used literature.

1. Antropov V.M. Forms of finding elements in dispersion halos of ore deposits. L., 1975.

2. Barsukov V.L., Grigoryan S.V., Ovchinnikov L.N. Geochemical methods of prospecting ore deposits. M., 1983.

3. Alekseenko V.A. Geochemical methods of prospecting for mineral deposits. M, 1989.

4. Udodov P.A., Shvartsev S.L., Rasskazov N.M. Methodological Guide to Hydrogeochemistry

- 6,032,161 to the prospecting of ore deposits. M., 1973.

5. Goleva G.A. Hydrogeochemistry of ore elements. M., 1977.

6. Krainov S.R. Fundamentals of hydrogeochemical methods for searching ore deposits. M., 1983.

7. Safronov P.I. Fundamentals of geochemical methods of prospecting ore deposits. L., 1971.

8. Sokolov S.V. and others. Temporary guidelines for conducting geochemical searches in closed and semi-closed territories. St. Petersburg, 2005.

9. Instructions on geochemical methods for searching ore deposits. Grigoryan S.V., Solovov A.P., Kuzmin M.F. M .: Nedra, 1983, 234 p.

10. Solovov A.P. et al. Handbook of geochemical prospecting for minerals. M., 1990.

11. Patent 8I No. 1171736;

12. Patent 8I No. 1755234;

13. RF patent No. 2224806.

14. RF patent No. 2221881.

15. RF patent No. 1524515.

16. Kuznetsov V.A. Shimko G.A. The method of step-by-step hoods in geochemical studies. Minsk: Science and Technology, 1990.

17. Patent AI No. 2396561.

18. Patent KI No. 2370764.

19. AO 02/24966.

20. Patent KN No. 2330259 (prototype).

21. Sokolov S.V., Marchenko A.G., Makarova Yu.V. Geological efficiency of geochemical searches using the ultrafine fraction method / Exploration and protection of subsurface resources,, 2008, No. 4-5, pp. 87-93.

22. Alekseev S.G., Voroshilov N.A., Veshev S.A., Shtokalenko M.B. The experience of using superimposed dispersion halos in forecasting and prospecting for deposits in closed areas / Exploration and protection of mineral resources, 2008, No. 4-5, p. 93-98.

23. Korobeinikov A.F. Forecasting and prospecting for mineral deposits, Tomsk Polytechnic University, 2009.

24. Krainov S.R., Ryzhenko B.N., Shvets V.M. Groundwater geochemistry. Theoretical, applied and environmental aspects. M .: Nauka, 2004.

25. Putikov O.F. Fundamentals of the theory of nonlinear geoelectrochemical methods of prospecting and exploration, 2008.

Claims (2)

CLAIM 1. The geochemical method of searching for mineral deposits, which consists in selecting soil from a selected network from the illuvial horizon of a layer of loose sediments, extracting a finely dispersed fraction of solid particles from them, quantifying the content of rare elements, determining secondary lithochemical aureoles, which predict the presence of ore mineralization zones , deposits of ore bodies and trace elements, characterized in that the soil samples are taken weighing 50-60 g in an amount of not less than 1000 samples per 1 km of the topsheet ² illuvium For each horizon, a suspension based on water is prepared in a ratio of 1:10, after which a fine fraction weighing 2-3 g and a particle size of 2-35 μm is extracted from each suspension for 1 min, dried at room temperature not less than 24 hours and put each of them on a glass palette made in the form of a tablet measuring 12x10x0.3 cm with a square marking of 5x5 mm in an amount of at least 200 squares, put in them the obtained dry fine fractions of samples that are analyzed for rare elements by laser ablation burning 5x5 mm square, followed by their content of chemicals build their distribution on the area map and identify anomalous zone maps contents indicator elements, which detect the presence of mineralization zones of ore deposits bodies and trace elements. 2. The geochemical method according to claim 1, characterized in that the laser ablation is carried out with a laser beam speed of 900 μm / s, a pierce depth of 5 μm, a laser beam energy of 65%, a frequency of 10 Ηζ, a beam size of 610 μm, a burn time of 50 s . 4 ^ ί)