Project source: project entrusted by Chinalco Resources Tibet Jinlong Mining Co., Ltd.; Work items of China Geological Survey (No.:12120113093); National 973 Project (No.:2011CB 403103); Special priority project of Qinghai-Tibet (No.:121201kloc-0/3037400).
Mainly completed by: Tang Juxing, Sun Xingguo,,, Li Yanbo, Wei,,, Duan Jilin, Yang Huanhuan, Zhang Zhi, Song Longjun and Hi-Tech.
Main completion units: Institute of Mineral Resources, Chinese Academy of Geological Sciences, Chinalco Resources Tibet Jinlong Mining Co., Ltd., Geological Team 5 of Tibet Geology and Mineral Exploration and Development Bureau, and Chengdu University of Technology.
Major achievements:
In recent years, great progress has been made in the exploration, evaluation and comprehensive research of epithermal deposits related to porphyry mineralization in the world, and many super-large deposits have been discovered, such as Lepanto, El Indio, Kingfield and other world-class copper and gold deposits. The famous Zijinshan in China is a typical high-sulfur epithermal copper-gold deposit, with epithermal gold deposits in the shallow part and porphyry copper-gold deposits in the deep part.
Since 20 1 1, the Qinghai-Tibet special optimization project, the geological survey project, the Chinalco resource exploration project and the national "973" project have respectively funded the Research on Metallogenic Mechanism and Prospecting Breakthrough of Porphyry Copper-Gold Deposits and Superficial Low-temperature Hydrothermal Copper-Gold Deposits in the Proliferative Orogenic Metallogenic System.
The research contents include: ① Whether there is epithermal deposits related to the porphyry copper-gold metallogenic system in the main metallogenic belt of Tibet; ② Preservation conditions of epithermal deposits in Duo Long ore concentration area; ③ Type determination and prospecting breakthrough of Rongna copper-gold deposit.
The new progress is as follows:
1. A super-large epithermal copper-gold deposit was discovered in Duo Long ore concentration area (Rongna ore section in Tiegelong South), and its ore body geological characteristics were basically found out.
The copper (gold-silver) deposit in Rongna ore section in Tiegelong South is the first copper (gold-silver) deposit that Chinalco Tibet Jinlong Mining Co., Ltd. made a major breakthrough in 20 13. This deposit has unique mineral assemblage, alteration assemblage and mineralization characteristics in epithermal deposits, and it is the first confirmed epithermal deposits in Tibet. Its controlled resource scale and estimated resource potential are far greater than that of Zijinshan copper-gold mine (Zhang Dequan et al., 65438+). Qiu Xiaoping et al., 2010; Liu Yu et al, 20 1 1).
The ore bodies in Rongna ore block are generally distributed in the northeast direction, and the ore bodies are controlled to extend to the northeast direction 1200m or more, and extend to the southeast-northwest direction by about 800m. The middle part of the ore body is not penetrated1136m (hole ZK 3205) (the thickness of the ore body is 9 14.77m, and the copper grade is 0.62%).
The ore body is uncontrolled in strike, dip and vertical direction, and the scale of the deposit needs to be further determined, which is expected to realize the super-large deposit. The average grade of copper in the ore body is more than 0.5%, the average grade of associated gold and silver is about 0. 1 g/ton, and the average grade of associated silver is about 2 g/ton. The ore is dominated by typical veinlets, with dispersed disseminated-dense disseminated ore locally developed. Ore minerals are composed of light blue, purple brown, chalcopyrite, chalcopyrite, chalcopyrite and chalcopyrite. From shallow to deep, turquoise blue and porphyry are abundant, and pyrite, chalcopyrite, bornite, chalcopyrite and tetrahedrite all account for some. Copper mineral content: sky blue > blue chalcocite > chalcopyrite > bornite > chalcopyrite > tetrahedrite > chalcocite. The total content of pyrite is between 3% and 35%, which is developed in the middle and upper part of the ore body, and the pyrite in the upper part is star-shaped disseminated. The pyrite in the middle and lower part is vein-like, and the thickness of individual veins is more than 20 cm. Pyrite is mostly developed at the edge or center of silicified veins and clay veins, and there are dissolved holes on the surface. Microscopic identification shows that pyrite was formed earlier than all copper minerals. The main gangue minerals are alunite, dickite, sericite, yingshi, anhydrite and clay minerals. Banded, layered, crusty, irregular alunite and dickite are developed in the shallow part, which are commonly found in high-sulfur epithermal deposits in porphyry metallogenic system (Hedenquist et al., 1994,1999; Sillitoe et al., 2003).
Geological, Alteration and Mineralization Distribution Map of No.24 Exploration Line in Rongna Mining Area
Diatomite (orthogonal polarization)
Alumina (orthogonal polarization)
Interestingly, there are a lot of chalcocite metasomatism of chalcocite and other sulfides in the ore, even in the ore as deep as 1 100 meters. These occurrences of chalcocite and chalcocite are the products of sulfide secondary enrichment zone in the traditional sense, or formed by metasomatism at shallow temperature, which is related to the challenge to the traditional theory of sulfide secondary enrichment and integration and needs further study.
2. Improve the "Industry-University-Research" mechanism and the technical system of commercial exploration and evaluation, establish the geological model of the deposit, estimate the resources, carry out the prospecting prediction of the deep edge and periphery of the deposit, and predict that similar deposit types can be found in Gaerqin and Dibaonamugang mining areas, thus pointing out the direction for regional prospecting.
(1) Guide Chinalco to establish a standardized and standardized system for exploration quality monitoring, conduct exploration evaluation according to N43- 10 1 and national industry norms, participate in the whole research work, and guide exploration evaluation.
② In Horqin and Namugang mining areas, there are timely and chalcedony. Holes, blocks and strips have been found, indicating that there are epithermal copper-gold ore bodies and porphyry ore bodies in the deep, which points out the direction for enterprise exploration and evaluation.
(3) The resources of copper, gold and silver in Rongna deposit in Tiegelong South are estimated by using Micromine software. The amount of copper metal is 5.286 million tons, with an average grade of 0.55%. The amount of gold metal is 74.8 tons, with an average grade of 0.08 g/ton; The amount of silver metal is 1 1 15.0 tons, and the average grade is 1. 17 g/ton. Among them, the content of industrial ore is: copper metal 45 1. 1 10,000 tons, with an average grade of 0.64%; The amount of gold metal is 59. 1 ton, with an average grade of 0.08g/ton; The amount of silver metal is 88 1.2 tons, and the average grade is 1.24 g/ton. It has made important contributions for some mining companies to complete independent technical reports and scientific decisions.
3. The significance and enlightenment of this study.
(1) New scientific understanding: Rongna porphyry mineralization is superimposed with epithermal copper-gold mineralization, and K 1m andesite and basaltic andesite are formed after mineralization, which covers the ore bodies that have suffered shallow erosion and plays a role in preserving the ore bodies, resulting in high-sulfur ore bodies not being eroded.
(2) New discovery of ore prospecting: The trinity combination of porphyry+breccia+epithermal ore body was found in Duo Long ore concentration area, and silicon caps were found in Gaerqin and Namugang, which pointed out the direction of regional ore prospecting and provided the basis for scientific decision-making.
(3) A new exploration idea: looking for shallow prospecting indicators of hyperspectral alteration combination; Determine the mineralization intensity of high-power IP; Supervise the exploration quality of international standards; Form a new model of "Industry-University-Research" and optimize exploration deployment.
(4) New breakthrough in ore prospecting: The Rongna ore section in Tiegelong South has reached the level of detailed investigation of super-large copper deposits from small ore point to more than 5 million tons in just one year, and submitted an independent technical report based on N43- 10 1 standard.
Energy spectrum diagram of chalcopyrite (chalcopyrite is a marker mineral in high sulfur epithermal deposits).
Note: rn1604-171.6-3-003cu3.29 (Fe 0.1) as1.15S4 copper sulfide ore.
Energy spectrum diagram of alunite (alunite is a symbolic altered mineral in high sulfur epithermal deposits)
Note: rn1604-171.6-2-005k1.02al3.31S2.44o14 ≈ kal3 (SO4).
4. Conclusion
(1) The ore fabric and mineral assemblage of Rongna copper (gold, silver) mine have typical characteristics of high sulfur epithermal deposits, which is the product of porphyry-epithermal metallogenic system. The middle-shallow part is a typical epithermal copper-gold deposit, and the deep part is mesosulfur epithermal mineralization superimposed on porphyry mineralization.
(2) The discovery of this type of deposit and great prospecting achievements have ended the history that no typical epithermal deposits has been found in Tibet so far, which has extremely important guiding significance for regional prospecting. This deposit is the first super-large epithermal copper (gold) deposit discovered in Tibet, and its ore characteristics and ore body size are very comparable to those of Zijinshan copper-gold deposit in Fujian. It is the "second" super-large high-sulfur epithermal deposits in China, and its scale is much larger than that of Purple Mountain.
(3) The scale of the ore body is huge, and the ore has the alteration combination of alunite and dickite, and the pyrite content is between 3% and 35%. Copper minerals are composed of light blue, purplish brown, chalcopyrite, bornite, tetrahedrite and chalcopyrite, especially light blue and purplish brown, which are rich in the depth of the hole above 1 100 meters.
(4) There is great potential for finding this kind of deposit in the periphery, and Gaerqin and Namugang in the bunker will be the key areas for the next prospecting breakthrough.
This project was selected as one of the top ten scientific and technological progress projects of Chinese Academy of Geological Sciences in 20 13 and geological society of china in 20 13.
Porous quartz (typical silicon cap at the top of epithermal) was found in Horqin mining area.
(2) Forecasting the total amount of important mineral resources in China.
Project Source: National Mineral Resources Potential Evaluation Project
Mainly completed by: Xiao Keyan, Ye Tianzhu,,, Sun Li, Yin Jiangning, Tang, Niu, Wang Xinqing, Cong Yuan, Lou, Shang Peng Qiang, Li Jingchao, Qi Shuaijun, Bai Wancheng, Zhang Ying and Wang Chunyan.
Main completion unit: Institute of Mineral Resources, Chinese Academy of Geological Sciences
Major achievements:
Mineral prediction and evaluation is the foothold of the whole mineral resources potential evaluation. After nearly eight years' work, the project mainly follows the guiding principle of "five unifications" in mineral prediction and evaluation, and ensures the smooth progress of the national resource potential evaluation project through technical theory research and development, method demonstration, technical training, multi-level guidance, achievement acceptance and achievement summary. The main achievement is to establish or improve the regional mineral prediction theory and method system with China characteristics, in line with China's geological conditions and based on China's unique metallogenic series theory; Relying on GIS technology, the whole process information technology of mineral prediction based on computer spatial database technology and data mining technology is developed. According to the provincial prediction results, the resource prediction and evaluation of 22 important minerals in China have been completed, and the resource potential has been preliminarily found out. On the basis of resource potential prediction, the prospecting zones of important metallogenic belts in China are divided, and some suggestions on the deployment of prospecting work are put forward. The main achievements can be reflected in the following aspects:
1. Theoretical framework of mineral prediction
On the basis of previous national support projects and "863" projects, a comprehensive geological information mineral prediction method based on ore-forming series theory, ore-forming dynamics theory and comprehensive information mineral quantitative prediction is developed. A mineral prediction framework with three prediction theories, three basic prediction processes and three basic prediction results is established, and a mineral prediction method based on comprehensive geological information of deposit model is put forward. Guided by the theory of multi-island arc plate tectonics, structural mapping based on metallogenic dynamics is carried out to build a solid foundation for the prediction of metallogenic tectonic environment; According to the prediction types of metallogenic series minerals, a comprehensive information prospecting model of ore deposits is established. Guided by the quantitative prediction method of comprehensive information mineral resources, the target area (minimum prediction area) is delineated and the undiscovered resources are estimated.
National Training Course on Mineral Resources Potential Evaluation and Prediction Software (West)
National acceptance meeting of important mineral forecast projects
Due to the accumulation of the first and second rounds of zoning and mineral prediction methods, especially the long-term practice and summary of the prediction methods by well-known domestic experts such as Zhao, Chen Yuchuan, Li and Zhu Yusheng, the prediction evaluation has a top-level design from the beginning, which ensures the consistency of the national prediction of a chess game and the summary of results.
2. Mineral prediction methods
Combined with the practice of mineral prediction, there are many innovations in mineral prediction methods. Compile technical documents such as Quantitative Prediction Method of Mineral Resources, Working Guide of 23 Mineral Prediction Methods, Estimation Method of Predicted Resources, MRAS Mineral Prediction Method, and Summary Method of Mineral Prediction Results. The results of the prediction method have been published in Frontier of Earth Science, Jilin University, Geological Bulletin and Geological Journal. The innovation of main prediction results is the innovation of geological prediction, especially the innovation of quantitative prediction method of deposit model system under the guidance of metallogenic series.
Comprehensive application of (1) metallogenic series in mineral prediction. On the basis of previous theoretical predictions such as "absence prediction" of metallogenic series, the theory of metallogenic series has been systematically applied and developed in the classification of mineral prediction types in comprehensive prediction areas, the delineation of prediction work areas, the establishment of prediction models and the summary of prediction results. Really combine theoretical prediction with collective actual information data prediction.
(2) Based on the key metallogenic geological processes of metallogenic series, six kinds of mineral prediction methods are summarized. Including sedimentary mineral prediction method, intrusive rock shape prediction method, magmatic hydrothermal mineral prediction method, stratabound endogenous mineral prediction method, metamorphic mineral prediction method, comprehensive endogenous mineral prediction method and so on. They are obviously different in basic mapping, prediction element extraction and quantitative prediction methods. This makes the prediction have reliable geological basis, methodological guidance and universality.
(3) The type of mineral prediction is the procedure of this prediction. Based on the prediction model of USGS, we summarized 77 national models of 23 minerals. On this basis, the provinces have divided nearly a thousand regional mineral prediction types based on the types of metallogenic series deposits, and on this basis, they have carried out the work of dividing the prediction work area, establishing the prediction model and compiling the prediction element map.
(4) Study on the new method of geological body parameter method of deposit model and its comprehensive application. Based on the theory of metallogenic system, the geological body parameter method improves and develops the metallogenic geological body, deposit and metallogenic geological anomaly as a whole. The key factors controlling the resource potential are studied, and it is considered that the larger the metallogenic system is, the greater the resource potential of the deposit is. By analogy with the parameters of known deposit system, the undiscovered mineral resources and their potential are predicted.
(5) The mode and method of compiling comprehensive forecast element map are put forward. The compilation method and model of comprehensive forecast element map in forecast area are established, and it is considered that only by establishing comprehensive mapping model can comprehensive information such as material, culture and distance in forecast element map be fully utilized.
(6) A three-dimensional prediction method of resources is proposed. Although there is no research on systematic three-dimensional modeling method this time, some progress has been made in prediction using deep geophysical data and deep geological drilling data. For example, in the process of resource estimation, we mainly designed parameters to predict the depth of geological bodies. For this parameter, we designed seven kinds of determination basis, including the parameters of ore-forming geological bodies obtained by geophysical inversion.
3. Comprehensive application of computer mineral prediction.
The comprehensive application of computer spatial database technology and data mining technology is a major feature of this prediction and evaluation. All basic data are established in GIS spatial database, and these data are effectively managed and utilized through data model. MRAS mineral resources evaluation system has been fully applied in this prediction and evaluation, and the extraction and synthesis of metallogenic information in geological data have been completed efficiently and quickly. Assist geological experts in delineating the minimum prediction target area and estimating the resources. Without computer spatial data management tools, it is unthinkable to complete the complex project of 25 kinds of mineral prediction. At the same time, the digitization of the forecast results will provide the convenience for the use of basic data for future standardization work.
4. Prediction results of 23 kinds of minerals in China.
The evaluation results of the national important mineral resources potential are summarized from the national level on the basis of the provincial and regional important mineral aggregate prediction results, and divided into three-level prediction areas at the national level. Its main contents include: from the national level, according to the accumulated proven resource reserves, the predicted resources of different provinces (autonomous regions and municipalities directly under the Central Government), the predicted resources of different depths, the predicted resources of different geological reliability and the predicted resources of different utilization degrees, iron, bauxite, copper, lead, zinc, tungsten, tin, molybdenum, rare earth, gold, silver, antimony and manganese are targeted. Through the summary and comprehensive analysis of 23 minerals in China, some important features such as proven reserves and predicted resources of important minerals in China are shown in the table:
Statistical table of resources of 23 mineral prediction areas in China
sequential
5. Talent cultivation
Through years of project technical training and practical work, a large number of young people from various provinces (autonomous regions and municipalities directly under the Central Government) have been trained. These young geological and mineral forecasters not only know the metallogenic regularity and mineral prediction, but also know the computer information processing technology. According to incomplete statistics, nearly 50 doctors and masters directly participated in the project, and nearly 500 people were trained in forecasting and evaluation nationwide, which provided talent guarantee for the normalization of mineral zoning in the future.
This project was selected as one of the top ten scientific and technological progress projects of Chinese Academy of Geological Sciences in 20 13.