Liu Yuhu
(The Fifth Geological Brigade of Henan Nonferrous Metals Geology and Minerals Bureau)
According to the national economic development of the demand for mineral resources continues to grow in reality and the current status of geological and mineral exploration, the national and provincial mineral exploration authorities have timely put forward the strengthening of deep-searching for minerals, to open up a second search for the space of the subject, which is of great significance to the implementation of the State Council Decision on the Strengthening of Geological Work. Decision of the State Council on Strengthening Geological Work", accelerate the realization of major breakthroughs in the search for minerals, and effectively improve the ability to secure resources, and promote comprehensive and coordinated sustainable economic and social development, is of great significance. On the issue of deep-searching for minerals, the author has the following thinking and understanding.
One, firm confidence and determination in deep mineral exploration
(1) deep mineral exploration is a certain historical stage of the mineral exploration work is inevitable. From the surface to the inside, from shallow to deep, from easy to difficult, has been the mineral exploration work to adhere to the principle, but also in line with the material dialectics. After about a century of exploration and development, surface minerals, shallow minerals have mostly been explored and developed, the possibility of finding minerals in the shallow part of the earth's crust is gradually decreasing, more and more difficult to explore, to the deep part of the earth's crust into the inevitable, it is not subjective want to want to question, but objectively sooner or later to do things.
(2) earth science research has shown that the deep crust of the mineral resources are very rich, there is a huge potential for finding minerals. Research has shown that there are large-scale fluid activities in the deep part of the earth's crust, lateral movement up to more than 100km, vertical penetration up to less than 9km. Where there is fluid activity, especially large-scale fluid activity, there is the possibility of forming minerals. Academician Teng Jiwen proposed that the favorable mineralization space in the depth of the earth's crust is 5~10km, this space is exactly the interlaced territory of the earth's internal, deep and shallow material and energy exchange and its deep power process, and it is also a variety of mineralization elements that have been mutated and coupled with the site of the transition, and adapted to the output of a large number of magma deposits and hydrothermal deposits. It is believed that the distribution of some large and super-large deposits and mineral concentrations is governed by deep elements such as mantle uplift, and is closely related to the inhomogeneity and anisotropy of the rock media and structures of the various circles and layers of the lithosphere. Scientific ultra-deep drilling wells in Russia's Kola Peninsula have been drilled to a depth of more than 12km, and copper-nickel sulfide, iron sulfide and platinum metal mineralization was found at 1.54-1.81km, with iron oxide mineralization as deep as 5.6km, and iron and titanium mineralization was found above and below 10km, and copper-zinc sulfide mineralization was found at a depth of 6-11km, and silver-bearing natural gold was found at 9.5-11km. China's continental scientific drilling project 5158m deep drilling also indicates the existence of mineralization at depth.
(3) domestic and foreign mineral exploration and development practices have proved that the deep search for minerals has broad prospects. According to incomplete statistics, foreign metal mineral resources mining more than 1,000m of large-scale mines have more than 80, such as the world's deepest mining of South Africa's West Rand gold mine, has reached 4,800m; Canada's Shawdebury copper-nickel deposits, has been mined to 2,000m, the current detection of the deepest ore body is located in the underground 2,430m; Australia's Olympic Dam copper and gold deposits, in the depth of 1,000m, found in the concealed The nearly upright deposit was found at a depth of 1000m. In recent years, the domestic deep search for ore has also achieved fruitful results. Such as Liaoning Hongtoushan copper exploration and development in 1100m see rich ore, Liaoning Benxi Daitai ditch in 1200 ~ 2000m depth found nearly 3 billion tons of super-large iron ore, Anhui Tongling dongguashan copper output depth in 800 ~ 1000m below, Fujian Zijinshan gold and copper deposits from the surface depth of 1,900 ~ 2,000m, Hubei Daye Iron Ore in the 1100m below the discovery of giant iron, copper, gold *** raw enrichment, gold, copper and gold ****. , gold *** raw enrichment ore, Jining, Shandong, found up to 1600m deep, 85m thick iron ore layer. In addition, Xinjiang, Jiangxi, Sichuan, Henan, Hainan and other places are found in the 500m depth of large metal deposits.
Two, standardize the concept of deep mineral exploration
As the country's attention to deep mineral exploration and the successive discovery of a number of large-scale deep metal deposits around, the academic community and production units of deep mineral exploration of the enthusiasm is high, the deep mineral exploration of new references, new terms appear frequently, deep mineral exploration of the depth of the boundaries of the various opinions, there is a need to unify the formulation of the relevant policies for the development and work of the standardization. It is necessary to harmonize them to facilitate the formulation of relevant policies and the standardization of work.
(1) The problem of reference. For the work of deep-searching for minerals, there are many different ways of referring to it in different parts of the world. For example, the Bureau of Geology and Mining of Liaoning Province calls it "the second mineral belt", some provinces put forward "the second space", academician Teng Jiwen puts forward "the second depth space", academician Zhao Pengda puts forward "the second mineralization search", academician Zhao Pengda puts forward "the second mineralization search", and academician Zhao Pengda puts forward "the second mineralization search". Academician Teng Jiwen proposed "the second depth space" to find ore, Academician Zhao Pengda proposed "the second mineralization space", China Geological Survey Bureau proposed "the second space to find ore", and so on. Obviously, "the second mineral belt" is not appropriate, because the "mineral belt" is a plane concept, such as the Tan-Tan-Lu fracture zone, the Qinling fold belt, Beishan mineralization belt, it is not the depth or three-dimensional concept. The "second space" is also not accurate, although it is a three-dimensional concept, but there is no direction. The "second depth space mineral search" is more appropriate, because he has both the meaning of the gradient, but also the direction of the instructions, or three-dimensional concept, more accurately expresses our current expectations and understanding of the deep search for minerals.
(2) The problem of depth boundary. On the current conditions, the deep search for ore depth boundaries how much is appropriate, there are different views. China Geological Survey Bureau of Mineral Resources Research Institute Zhu Yusheng and other proposed 600 ~ 2500m, Teng Jiwen academician proposed 500 ~ 2000m, Professor Ye Tianzhu proposed 2000m to shallow, the former deputy director of the State Reserve Commission Yan Tiexiong put forward 1500m to shallow, China Geological Survey Bureau put forward 500 ~ 1500m, Henan Province, put forward 1500m to shallow, and so on. Depth boundary is not a simple numerical problem, it involves the formulation of national policies and norms, the focus and direction of scientific research and geological exploration units, the development of geological exploration equipment and instrumentation goals and a series of issues, must obey the laws of geological exploration work, and the current level of economic and scientific and technological development is compatible. Depth is too shallow, lose the significance of the deep search for minerals; depth is too large, such as 3000m, 5000m, although the desire is very good, or very exciting, but blindly ventured, detached from the actual, play the numbers game, it is meaningless. The author believes that the depth of 500 to 1500m called the second depth of space is more appropriate. This is because, on the one hand, 500 ~ 1500m of this space of mineral resources can meet the current and future a fairly long period of China's demand for mineral resources. Over the past century, the vast majority of non-energy solid minerals exploration and development depth in China in the shallow 500m, most of them in the shallow 350m. And 500 ~ 1500m this 1000m depth space, is the original depth of twice, even considering the economic and social development of mineral resources demand growth rate, can also meet the current and future demand for a period of time. On the other hand, the depth of 500 to 1500m, is the current exploration and mining equipment can be reached or after efforts can be reached, and more than this depth, the exploration and mining difficulty increases, the cost increases, the economy is not necessarily reasonable.
Three, to rule out the impact of the constraints of the deep search for minerals
(1) mining rights to set up management problems. First, the prospecting rights set too small, too scattered, not conducive to the whole survey, not conducive to the comprehensive study of mineralized zones, not conducive to the deep search for minerals, looking for big mines. Secondly, the threshold of entry into the prospecting rights market is too low, resulting in the setting of too many mineral rights, so that a lot of speculators to take advantage of the situation, some prospectors circle but not exploration, the purpose is to speculate and speculation. For example, in Henan Province, there is basically no blank area for the setting of mineral rights in the important mineralization zone, and it is difficult to set up new mineral rights. Third, the price of prospecting rights is too high. At present, most of the local prospecting rights are through the form of bidding and auctioning to let, have the economic strength of the enterprise to obtain prospecting rights and no exploration capacity, and have the ability to explore the geological exploration unit due to economic reasons and not get the prospecting rights.
(2) Prospecting and mining unit coordination problems. Deep search for a very important direction is the deep and around the existing mines. For example, there are coal mines below the bauxite exploration, there are hydrothermal copper deposits below the molybdenum exploration, fluorite mine under the lead-zinc, molybdenum exploration, and even the same ore type of deep and peripheral exploration. However, due to the different types of minerals or the lack of exploration capacity, the mining right holders are not very active in deep exploration. It is necessary to coordinate the interests of the exploration and mining units and mobilize them to carry out deep exploration enthusiasm.
(3) exploration risk problem. With the increase in depth, the exploration difficulty increases, the corresponding exploration risk increases. Most of the ground exploration unit is a business unit, limited economic strength, low risk resistance, can be said to be more than enough. Must develop appropriate support policies to support geological exploration units for deep exploration; or develop preferential policies to guide the strength of enterprises, and geological exploration units to jointly invest in deep mineral exploration work.
(4) technical equipment. The depth and accuracy of the current physical exploration instrumentation can not meet the needs of deep exploration. Especially in the grass-roots exploration units, drilling technology is weak, solid metal ore exploration can be constructed more than 1000m depth drilling rigs are not many.
(5) geological information **** enjoy the problem. Finding ore in the deep is very difficult, must be through the region, physical, chemical, remote and other kinds of geological information, comprehensive research, in order to determine the new target area for finding ore, or must be on the original exploration information to re-examine, secondary development in order to make a breakthrough in the deep and around the exploration of the mine. However, at present, the borrowing procedures of geological data are complicated. Especially due to sectoral interests, in recent years, the formation of state-funded basic geological survey results, research results, remittance of slow, and some even do not remit. This leads to other geological exploration units do not have access to new basic geological information, difficult to select areas, affecting the progress of deep-search for minerals.
Four, explore the methods and ways to find minerals in the deep
(1) to strengthen the deep mineralization and mineralization prediction research. Theory comes from practice, but can have a huge guiding effect on practice. since the 1990s, the world's mineralization theory research is getting deeper and deeper, and new theories and understanding of the genesis of mineral deposits continue to emerge, which inspires and guides the world's search for solid minerals and exploration. For example, the crustal continuous mineralization theory puts forward the crustal continuous mineralization model of the aeolian vein deposits, that the metamorphic rocks from the sub-green schist phase to the mafic phase can have vein gold deposits, and that gold deposits can be formed continuously in different crustal depths, at least in the crustal section more than 15km below the ground, and that gold deposits in the different metamorphic rocks belong to a group of continuous deposits with the same cause combination. This model of mineralization breaks the previous understanding that gold can not be formed in mafic rocks. For example, the theory of deep fluid (metallogenic) action believes that large-scale fluid activity exists in the deep part of the earth's crust, which fundamentally changes people's understanding that the deep part of the earth's crust is dry, without a large amount of free fluid activity, without hydrothermal metallogenesis, and the deep part of the earth's crust can't make large-scale lateral fluid transport, thus providing a new way of thinking and direction for people's search for minerals and investigations. In addition, the study of mineralization zones can also help to determine the target area of deep mineral search.
(2) Comprehensively update the basic information of deep-searching for minerals. The relevant state departments should make plans and increase investment to accelerate the process of regional geological survey, regional chemical exploration, regional gravity, high-precision aerial physical exploration and comprehensive survey of resource potential, focusing on updating the old information with low precision and early working age. Carry out deep geological mapping, determine the thickness of sedimentary cover structure and weathering layer, study the undulation change of the basement, determine the extension of deep and large fractures, prepare the distribution map of deep granite, etc., and circle and preferably select the target area of deep mineral searching from the analysis of the regional metallogenic background and metallogenic law.
(3) Strengthen the research and development and popularization of the application of high-tech equipment for deep-searching exploration. "If you want to do a good job, you must first sharpen your tools." Make full use of today's scientific and technological progress, especially military technology, vigorously strengthen the aviation gravity, gravity gradient, aviation magnetic gradient and time domain aviation electromagnetic technology research, improve the depth of aerial physical exploration and the ability to distinguish weak information. Aiming at the key technical problems existing in the current deep exploration, such as shallow depth of detection, low precision and resolution, and poor anti-interference ability, etc., we will focus on deploying the research and development of large-depth and multi-functional electromagnetic detection technology and equipment, the research and development of hard-rock three-dimensional seismic detection technology and equipment, the development of a series of large-depth rock drilling equipment and technology, the strengthening of deep and complex rock drilling technical problems, and the strengthening of the two-dimensional of gravity, magnetism, and electricity, Three-dimensional inversion interpretation of new technology research, and so on, and constantly improve and establish from aviation, ground to underground three-dimensional exploration technology system, for the deep search for minerals to provide technical support.
(4) Highlighting the key points, accumulating experience and making good demonstration. In accordance with the first easy and then difficult, from the known to the unknown principle, highlight the focus of the work, make breakthroughs in some areas, accumulation of experience in deep-searching for minerals, and play a demonstration-led effect. Currently in Henan Province, to work from the following aspects, first, the old mining area deep and around. First, the deep part of old mining areas and the periphery. For example, the deep part of the gold mining area of the Little Qinling Gold Mine, the bauxite exploration under the coal of the Shanxian Mian Coal Field and the Xin'an Coal Field, the deep part of the Maoyang Iron Mine and the Anlin Iron Mine and the periphery of the iron mine, and the deep part of the known mining area of the Tongbai-Dabie Mountain area for the polymetal exploration, etc. Second, the important metallogenic zone. Secondly, it is an important mineralization zone. Such as Banshan Mountain, Xiong'er Mountain, the western section of gold, molybdenum ore exploration, Xiong'er Mountain - outside the Fangshan Mountain area gold ore exploration, Ma Chaoying fracture zone gold ore exploration, molybdenum, lead and zinc ore exploration in Luanchuan area, Dabie Mountain area, north and south of the two zones of molybdenum, copper and molybdenum ore exploration, and so on. Third, looking for hidden rock bodies. Especially the Yanshan period in acidic rock bodies favorable for mineralization. Increase the exploration of hidden granite bodies in Xiong'er Mountain area and Lushan Mountain area. Fourth, the regional physical and chemical exploration anomaly concentration area. Such as east Henan, southeast Henan covered area magnetic anomaly verification, Lushi area, Fangcheng area, Xixia - Xichuan and other areas of physical and chemical exploration anomaly checking.