西藏罗布真铅锌多金属矿床地质特征及成因

罗布真铅锌多金属矿床处于西藏昂仁县境内，位于冈底斯南亚带西段。在分析区域成矿地质背景、矿床地质特征的基础上，结合矿区最新勘查成果，对区内控矿因素、赋矿围岩地球化学特征和矿床成因进行了分析。研究表明：①矿体主要赋存于古新世-始新世林子宗群帕那组（E2p）英安岩与黑云母斜长花岗斑岩、二长花岗斑岩的接触部位，主要受NWW向断裂控制，同时也受地层、岩浆岩等因素制约，矿体多呈透镜状、似层状产出，分带明显，矿化蚀变强烈，主要有硅化、绿泥石化、碳酸岩化、黄铁矿化；②赋矿的黑云母斜长花岗斑岩与英安岩形成于始新世，为同一期岩浆活动的产物；③黑云母斜长花岗斑岩与英安岩具有相似的地球化学特征，表明两者具有相同的初始岩浆起源，其中，黑云母斜长花岗斑岩属于Ⅰ型花岗岩，其岩石成因类型与我国典型斑岩型铜矿的赋矿围岩相同；④罗布真铅锌多金属矿床为具有幔源属性的岩浆热液矿床，成矿物质具有多源性特点，成矿年龄小于51 Ma。在上述分析的基础上进行了找矿预测，认为落布岗木北部Ⅱ#、Ⅲ#矿化带所在的B潜力区深部具有较好的成矿远景，值得进一步开展工作。

Geological Characteristics and Genesis of Lubuzhen Pb-Zn Polymetallic Deposit in Tibet

Luobuzhen Pb-Zn polymetallic deposit in western South Gandese metallogenic belt is located in Angren County in Tibet.Based on the analysis of the regional metallogenic geological background and the geological characteristics of deposits，combined with the latest exploration results of the mining area，analysis of the ore-controlling factors， geochemical characteristics of the ore-hosting rocks and deposit genesis are conducted.The study results show that:①the mineralization bodies are mainly hosted in contact position between Paleocene-Eocene of Linzizong Group Pana Formation of dacite and biotite plagioclase granite porphyry，monzonitic granite porphyry，the orebodies are obviously controlled by NWW fracture，and also controlled by strata and magmatic rock，the orebodies are distributed with elenticular and stratoid forms，and obvious zoning characteristics，the mineralization alteration is very strong，and silicide，chloritization，carbonate lithification and pyritization are the main alteration in mineralization types；②ore-bearing biotite plagioclase granite porphyry and dacite are formed in Eocene and it is the product under the same magmatic activity；③biotite plagioclase granite porphyry and biotite have similar geochemical characteristics，which indicated that they have the same initial magma origin， biotite plagioclase granite porphyry with the geochemical characteristics of Ⅰ type granite，the petrogenetic type biotite plagioclase granite porphyry is the same as the ore-hosting rock of porphyry copper deposit in China；④Luobuzhen Pb-Zn polymetallic deposit belongs to the magmatic hydrothermal with mantle-derived properties，the ore-forming materials have multi-source characteristics and its metallogenic age is less than 51 Ma.Based on the above discussion results，the relative prospecting prediction study is done.The results show that the potential area B，where the Ⅱ# and Ⅲ# mineralized belts are located has good metallogenic prospect in north of Luobugangmu area，it is worth conducting further prospecting and exploration work in the area.