| Yapai-Anding iron ore deposits in Funing County of Yunnan Province is a new deposits, the tectonic position in the South China fold system, the fold belt northwest to the Mile-Shizong fracture and the Yangtze platform boundaries; Southwest area bounded by the Red River fracture and Ailaoshan block adjacent to the south and east were extended into Vietnam and Guangxi. Mine is located in Guang Nan-Fu Ning rift trough, the trough has experienced uplift rift-rift-again split-the depth of subsidence-die out the five stages. This paper contrapose Yapai-Anding iron ore characteristics, through field investigation and indoor comprehensive study, more detailed analysis of the Yapai-Anding iron ore mine geologic feature, combined with the major elements,trace elements,rare earth elements, described ore-controlling factors and the relationship of mineralization, ore material source of ore-forming fluid migration in the channel and mineral precipitation in place, in this based on the analysis of genesis.Found two iron ore body (Ⅱ,Ⅴorebody) in the mining area by Exploration work, so far not fully control the size of ore body, the two ore bodies were layered,bedded vein consist in diabase gabbroand the system of Permian (P1) of the belt-skarn zone. Ore than major structural change in the structure of granular texture,false account of the structure,ring structure,and a half from the shape-it is shaped structure; the main structure with block structure,the infection-like structure and fine vein structure. Iron ore in the main metal minerals are magnetite,pyrite,chalcopyrite,ore gangue minerals are mainly garnet,diopside,plagioclase,hornblende,quartz,calcite,green and epidote and other debris. Rock alteration can be divided into four phases, magma formation of major mineral phases are plagioclase,diopside,calcite,dolomite; magmatic stage of skarn formation of the major minerals are garnet, through pyroxene,plagioclase,epidote,magnetite; later stage skarn formation of the major minerals are amphibole,magnetite,quartz,epidote; quartz-sulfide minerals are the main stages of the formation of quartz,chlorite,calcite,epidote,pyrite,chalcopyrite. Yapai-Anding iron ore deposit is divided into four stages:stage magmatic,magmatic skarn stage,after stage of skarn, quartz- sulfide phase.Geochemistry of intrusive rocks that mine rocks are calc-alkaline series of potassium, iron ore and has a pro-specificity, in which the tectonic environment of continental margin arc, magma derived from the transition through the crust and mantle contamination. Sedimentary geochemical characteristics indicate that the Early Permian sediments of mining in the oxygen-rich environment of salt water marine deposit. REE characteristics of garnet show light rare earth-rich garnet, loss of HREE, Eu positive anomaly, which is magmatic garnet REE curves, but also "explain the causes of type" REE pattern, and reflect the mining pomegranate Stone is the son of rich iron garnet. Calcite REE characteristics indicate a magmatic origin of its parts, some of which are sedimentary origin, indicating that both made accountable. Skarn, magnetite, garnet is very similar morphology and have the same REE characteristics, indicating that they are from the same hydrothermal precipitate out. Skarn,dolomite,diabase gabbro REE characteristics of the three completely different, indicating that the REE characteristics of skarn is not inherited from the rock is not a single one from the surrounding rock, is formed between the two account.Combined with regional data, geological features and geochemical analysis of the deposits from the five aspects of the controlling factors. Indo-Chinese epoch of the Yangtze plate and the Huaxia plate happen A-type subduction occurred for the formation of deposit base and providing a dynamic source of heat driven; regional faults control the distribution of the rock, iron ore body produced in the rift trough, of the ore bodies formation in connection with 1anticlines and F6 fault, indicating structure is an important factor restricting the formation of ore bodies; diabase gabbro is the formation of ore deposits in rock, magma evolution of ore-forming process to provide a heat source, is the first element of the formation of iron deposits; dolomite formation of the deposit of the precipitation agent (calcium), its joint fracture is the migration channels and hydrothermal mineral deposition sites; contact zone is favorable ore space. The main ore deposit formation is contact metasomatism, explain Yapai-Anding skarn iron ore is contacted metasomatism. |
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