| The tectonic zone of Leiwuqi-Zuogong is located in san-jiang region of eastern Tibet known as"treasure land"and sandwiched between famous Ban gong lake-Nu jiang river and lan cang river ancient tectonic plates. And it has the characteristics of complex geological structures, fully developed stratums, frequent magmatic activities, abundant mineral resources. What's more, it is an important part of san-jiang metallogenic belt in eastern Tibet.According to the mineral resources potential assessment project in Tibet, a detailed discussion was carried out in this paper based on the previous theoretical system and associated with the latest results of regional geology and mineral resources survey in Leiwuqi-Zuogong zone, including regional stratigraphy, regional structure, regional magmatic activities, regional metamorphism, tectonic evolution. Through the research of geological characteristics of typical lead-zinc in studied zone and utilizing the data of geophysics, geochemistry, remote sensing geology and so on, it was concluded that the Leiwuqi-Zuogong tectonic zone was controlled by the tectonic-magmatic rocks-stratum coupling. In addition, the deposit types and the nature law of deposit distribution was further analyzed and summarized and the metallogenic potential prospect area was delineated.In this paper, the following main results and understanding were obtained:(1) With the evolution of Paleotethys, from the century of Devonian to early carboniferous, chang-du plate came into the Paleotethys ocean - continent evolution system, and the chang-du plate split off"fan yang zi plate"and became an independent land. At the same time, due to the splitting and sinking of lan cang river, Zogang plate separated with chang-du plate. And then, continental margin arc system and inland orogenic system were experienced and the conversion of two tectonic system.(2) The typical deposits represented by la ruo ma lead-zinc polymetallic deposits have been investigated systematicall and it was proposed that the deposit type in metallogenic belt was mainly consist of carbonate rocks and hydrothermal rocks types.(3)The ore-controlling factors of lead and zinc deposit in studied region was tectonic—magmatic rocks—stratum coupling. The stratum mainly consisted of carbonate in Triassic was an important source of ore in Riwoche-Zogang metallogenic belt, the irruptive rock of yinzhi-yanshan period was also crucial mineral source, structural belt have provided the necessary conditions for the circulation and enrichment of metallogenic material in metallogenic belt.(4) Deposit of Riwoche-Zogang metallogenic belt have the distribution rule of congregating in partial and zonal distribution in the whole.(5) It was summarized six prospecting symbols of stratum and rock, magmatic rock , structure , Geophysics ,geochemistry, wall rock alteration, and delineated the jia-shankar copper, silver, (lead, zinc) polymetallic prospect area and so on seven large prospecting area. |
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