| The mineralization of Puer-LoBo-Montain Pb-Zn mine was located in the southern of Lanping-Simao basin which names Sanjiang metallogenic belt. It was sandwiched in the middle by the Ailaoshan fault and the Lancang-River fault.Before this research, Someone has made a preliminary study about this deposit. Results of the study as follows:researchers believe that the formation of the mineralization is Overthrust structure control. It Belongs to epigenetic deposits. And it is classified as type MVT type lead-zinc deposits.Based on the research of predecessors, According to detailed geological survey of mining area, combined with the interior mirror identification and draw ore spatial distribution, mineral composition, mineral symbiotic combination, structure and wall rock alteration types; By the trace rare earth elements research, S-Pb-Sr stable isotope research to talk about the ore forming material and fluid sources.The main results and cognition are as follows:(1) Within the scope of the mining area, the surface can see the layer is that Permian, Jurassic and Quaternary; In this place the layer which exist mine is named lower Permian which lithology is gray black-black gray micritic rocks and bioclastic limestone; The main construction contents:nearly north-south fracture which name is F1 and the east-west fault F2, F3, F4, LoBo-Montain anticline axis is close to the southwest. In the process of structure formation of the nappe formed radish mountain arch core and interlayer fracture zone between the two wings, provide the space for the padding and enrichment of ore-forming materials.(2) The body of Pb-Zn mine mainly located in Two-lower-Triassic’s bioclastic limestone and micritic limestone. Most of ore were outputed by the states of Veinlet,Lenticular,stratoid or lump, The others were outputed by Disseminated state. Breccia containing gray bioclastic limestone, gray-black-containing carbonaceous micritic limestone; is making compoent parts for the country rock of this mine.the mineral assemblage of ore is simple, galena and pyrite with arsenic, orpiment and little arsenopyrite are the constituents of ore. The surrounding rock’s alteration is weak.Sometimes we can see the carbonation, weak silicification, pyrite, limonite, and other low-temperature alteration.(3) Select some rocks for analysis which name are calcite, galena, minerals, surrounding rocks.Their distribution patterns are similar to hydrothermal calcite and galena which shows that LoBo-Montain Pb-Zn mine’s lanthanon in ore-forming fluids is mainly Inherited surrounding rock from water-rock reaction. Isotope analysis result from the sphalerite, galena, pyrite, calcite and other mineral:S elements comes from marine sulfate; Pb isotopic results showed that forming materials mainly from the upper crust; Sr isotope study results indicate that the formation of a mineral brine fluid from the basin brines.(4) The mineralization of LoBo-Montain Pb-Zn mine can be summarized as follows:Strongly tectonic movement which activation basin rock metal mineralization, and it forms an early source bed; In the driving of the tectonism, the ore-forming fluid begins to activate and migration away rock in the basin of a large number of metal mineralization. Eventually they migrated into the open space which located in the interlayer fracture zone, dissolution collapse breccias, fold turning end and the site of collapse. It is mixed with the existing reduced sulfur which containing biological. They precipitate mineralization together and they rapid precipitation mineralization together. MVT type Pb-Zn mine and LoBo-Montain Pb-Zn mine are very similar. The formation of two minesis different maybe the reason is jet deposition.But all of them is MVT type. Therefore, I belived that MVT is the formed reason of LoBo-Montain Pb-Zn mine, which it can classified as MVT type lead-zinc deposits. |
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