Study On 3D Geological Modeling Method And Prospecting Prediction Of Deep Comprehensive Information In Mining Area

Mineral resources are the material basis of human economic and social development and scientific and technological progress,and any form of social development can not be separated from the consumption of mineral resources.With the rapid decline in the discovery rate of near-surface deposits,it has become a trend of global mining development to look for more resources in the deep.With the deepening of geological prospecting,most areas of China,especially in the middle and eastern part of China,have entered the stage of prospecting for deep or hidden ore,and exploring deep prospecting space is the only way to achieve a breakthrough in prospecting.In 2016,the State's key R&D program "Exploration and Mining of Deep-Earth Resources" began to be implemented,with a view to substantially improving the basic theoretical level of deep mineralization and accumulation and evaluation and prediction of deep-earth resources,tackling the key technologies of deep-earth resources exploration,and improving the exploration and mining capacity of deep-earth mineral resources and energy resources.With the rapid development of computer 3D technology,the data integration technology with 3D geological modeling technology as the core has gradually become an important technical means for deep prospecting.Focusing on the difficulties of 3D geological modeling and the difficulty of quantitative extraction and synthesis of deep prospecting information,and based on the geological anomaly theory,comprehensive information evaluation theory and metallogenic multi-fractal theory,the metallogenic prediction method of comprehensive information based on 3D geological modeling is adopted in this paper.In order to explore a new approach to the extraction and identification of geochemical comprehensive anomalies and an effective method for ore prospecting and prediction of deep integrated information,and to promote the improvement of the basic theory level of deep mineralization and the evaluation and prediction of deep resources.this paper mainly studies the methods of three-dimensional geological modeling,extraction of multi-element geochemical anomalies,borehole primary halo prospecting and deep-seated comprehensive information prospecting and predicting.The main achievements are as follows:(1)according to the working degree and data characteristics of existing metal deposit exploration,the 3D geological modeling method of ore area scale is studied.For special geological bodies,such as ore bodies with high exploration degree,3D geological modeling method based on borehole geological interpretation can be adopted,and for exposing limited geological bodies in the depth of mining area,such as rock mass,strata with wide distribution,3D geological modeling method based on the cutting section can be used,and the more important complex geological bodies,such as structures,veins and special alteration bodies,which are exposed by deep boreholes but whose spatial distribution is not continuous,the 3D geological modeling method of complex geological bodies based on block interpolation can be applied.(2)based on the study of the traditional geochemical anomaly extraction methods,according to the nonlinear characteristics of element distribution and the advantages of factor analysis in analyzing the characteristics of multi-element symbiotic assemblage,In this paper,a method of extracting multi-element comprehensive metallogenic anomalies by factor analysis and fractal analysis is proposed.The C-A multifractal model of the main metallogenic factor fits straight line into four sections and can be divided into geochemical background,regional anomaly,local anomaly and extreme anomaly according to its inflection point.The local anomaly and extreme anomaly can well reflect the favorable ore-forming geological conditions such as rock mass,structure and ore-bearing strata,and can be used as the basis for the delineation of the prediction target.The extraction of geochemical anomalies from 1:50000 stream sediments in the study area proved effective.(3)on the basis of studying the prospecting method of primary halo,3D geochemical zoning of borehole primary halo is completed by using 3D visualization block modeling and element combination characteristic analysis.Factor analysis and C-V 3D multifractal model are used to extract the ore-forming anomalies of the main metallogenic factors,and based on the prediction criteria of structural superposition halo,the geochemical parameters such as Sb/Bi,frontal halo factor F3 and tail halo factor F4(F3/F4> 1)were used to infer the deep ore-causing anomalies,and the synthetic ore-indicating anomalies of the primary halo in the borehole were extracted.(4)based on the research of 3D geological modeling method under different conditions,the 3D geological modeling and visualization of Kekesala mining area in the eastern section of Bolokenu are carried out.On the basis of studying the geological characteristics,metallogenic regularity and typical deposit characteristics of the district,3D geological models including surface model,stratigraphic model,rock mass model,tectonic model,alteration zone model and mineralized body model are established.Based on the analysis of the 3D metallogenic geological conditions of the typical veins,such as L2+1 and L10 in Kekesala mining area,the metallogenic model of the deposit in the study area is established.The Kekesala deposit is mainly skarn type deposit,and its mineralization is controlled by the combination of magmatic rock,stratigraphic lithology and tectonics.(5)under the guidance of metallogenic prediction theory,based on the established 3D geological model of mining area,the comprehensive ore-prospecting model of the study area is established by using the analytic hierarchy process(AHP)through the three-dimensional integrated superposition analysis of known orebody and geophysical,geochemical and remote information.Geological anomalies,such as Ore-bearing surrounding rock,ore-controlling rock mass,ore-controlling intrusive contact zone structure and wall rock alteration,geophysical anomalies such as magnetic and electric,and geochemical ore-indication anomalies such as stream sediments and borehole primary halo have been extracted in 3D space.Through 3D block modeling,the information of multi-element metallogenic anomaly is converted into the attributes of blocks,and the prediction element superposition method is adopted.Through the optimized combination of the various conditions of blocks,the comprehensive calculation of attributes completes the 3D metallogenic prediction of the studied mining area.Four targets of class A,six targets of class B,and nine targets of class C are delineated.