Comprehensive Evaluation Of Soil Geochemical Anomalies And Prospecting Prediction In Shuihekou Gold Mine, Funing, Yunnan Province

The area of study is located in the Tian Peng town of Funing County of Wenshan Prefecture, which belongs to the southeast of Yunnan Province, the location in the southeast of Yunnan belongs to "Golden Triangle"(Yunnan, Guizhou, Guangxi), is an important micro-disseminated of gold mine concentration area of China. Affected by the rift of Yunnan-Guizhou-Guangxi evolution, all levels of tectonic zone develop, magmatic activities are intense, providing favorable conditions for mineralization for the micro-disseminated of gold mine which is Low temperature and hydrothermal, and it has been around many large and small gold deposits in the study area. The faults and results of area develop, and the result of 1:200000 stream sediment shows anomalies existing in the southern area, it has very favorable prospecting prospect. Finding the micro-disseminated type of gold mine in the main research area of Cambrian in the southeastern Yunnan for gold is also a breakthrough. Looking for micro fine disseminated type gold deposits in the study area of the karst mountain landscape area and the low level of research, soil geochemical method is undoubtedly a very direct and effective means. Geochemical anomalies is often divided into mine caused by abnormality and non ore caused abnormality, comprehensive evaluation of abnormality is a key ring of sieving ore induced abnormality and forecasting of prospecting.Based on the on the 6022 soil geochemical samples taken to test out content data Au, Hg, As, Sb of four elements whose have been processed, Using factor analysis and cluster analysis to study the correlation between elements, And found good correlation of four elements whose, as a quest for gold indicator element; Traditional iterative method and comparison of method of fractal analysis after determining the threshold in a circle and each element geochemical anomalies and abnormal individual elements of a comprehensive, And from abnormal size, density zoning, unusual strength and nested elements and other aspects of the individual anomalies were evaluated. Recycling obtain basic geological data for anomalies evaluated by remote sensing interpretation and field mapping:Abnormal Analysis and superimposing respectively geochemical data and lithology overlay analysis of faults were fractal dimension statistics. Finally, the results of prospecting signs and abnormal comprehensive evaluation, delineation of the key areas in the study area, in order to achieve prospecting prediction.In this paper, the main conclusions are as follows:1. In the low mountain karst in the study area and the landscape areas to find the microgranular disseminated type gold deposit, the soil geochemical method is undoubtedly the most direct and effective method, based on the study area to do the soil geochemical sampling horizon and granularity analysis found that sampling horizon in B layer, analysis of particle size under 200 mesh is the best; To test the Au, Hg, As, Sb four element data correlation analysis found that the correlation of these four elements, can be used As finding the microgranular disseminated type gold deposits of indicator elements.2. By comparing the traditional iterative method and fractal method, to determine the fractal method is used to determine the threshold of soil geochemical anomalies delineated, the study area can be divided into four synthetical anomaly area, has the following characteristics:unusually large, with a total area of 7.68 square kilometers, accounting for 31.5% of the total area of the soil geochemical survey; Good continuity, all along the north west to show long strip or nearly rectangular shape distribution; Abnormal high intensity, I, II, III number comprehensive anomaly of Au element within the extremum respectively achieved 188×10-9、90.5×10-9、62×10=9 within comprehensive anomaly IV Sb elements of extreme value for 562×10=6; Concentration zoning obviously, Au and Sb has 4 concentration zoning characteristics, with a total area of 0.34 square kilometers, Hg and As level 3 concentration zoning characteristics, inside with area of 0.02 square kilometers; Elements nested sex good, the comprehensive anomalies within the Au, Hg, As, Sb four elements of each set of characteristics.3. Contrast 1:200000 geochemical exploration achievements in the study area delineated abnormal and the 1:1 million exception of soil geochemical survey work and found abnormal morphology from north and south to nearly elliptical continuous abnormal morphology into north west strip interval distribution, abnormal area is reduced to half of the original, for the same area adopts different precision soil geochemical work income effect is not the same, the higher the accuracy, delineating the abnormal shape more real, abnormal area is smaller, more conducive to narrowing the prospecting target area.4. Through the study on the field geological work realized that:(1) the fracture structure in the study area development, affected by the regional structure, the main development in north west and north east to fracture, through the analysis of fracture mechanics properties and joint statistical analysis found that north west to fracture for the region’s main fracture; (2) the study area are mainly open layer to the lower Cambrian, lithology is given priority to with carbonate rocks, lithofacies built for an impure carbonate rocks, the northeast is exposed group, devonian system cui peak mountain lithology for fine clastic rocks.5. Through the study of geochemical anomalies quantitatively, respectively, and the relationship between the strata, lithology, found the Cambrian system in the study area of background value is higher than the southeast yunnan area background value, illustrate the Cambrian system in the study area is more advantageous than the regional gold, study the main gold bearing horizon for ∈2t1、∈211、∈212 the main gold bearing for carbonate rock.6. The study area soil geochemical anomaly pattern of distribution and structure of composite degree is high, are in north west to the distribution, the main fracture strict control of the north west to the overall distribution of abnormalities, abnormal good often is holding by fracture or produced in north west and north east to fracture intersection parts; And by means of the fracture structure in the study area being fractal dimension analysis found that the fractal structure development good local anomaly intensity is high, further shows the fracture structure in the study area of abnormal concrete control function, also confirm the structure is the primary control factors of the microgranular disseminated deposits.7. Through the abnormal morphology, intensity and concentration zoning and elements nested geochemical anomaly characteristics and strata, lithology, structure, a comprehensive evaluation of geological conditions on the abnormal according to the soil geochemical marks, structure, strata and lithology, select six key prospecting target areas.