成矿期碳酸盐矿物LA-ICPMS原位U-Pb定年可精确限定成矿作用发生时间，为矿床成因研究提供依据。柴北缘锡铁山铅锌矿床主要工业矿体为赋存于大理岩中的非层状矿体，该类矿体可能形成于围岩滩间山群火山岩变质变形期后的热液叠加成矿作用，成矿期发育方解石、铁白云石、菱铁矿和白云石等热液碳酸盐矿物。本申请拟在矿床地质、岩相学、矿相学研究基础之上，采用LA-ICPMS原位微区U-Pb定年分析技术对非层状矿体成矿期热液碳酸盐矿物开展年代学研究，精确限定非层状矿体成矿时代，查明热液叠加成矿作用与区域地质事件耦合关系，并结合热液碳酸盐矿物和围岩C-O及原位Sr同位素示踪，分析成矿流体来源及流体-围岩相互作用，进一步阐明非层状矿体成因机制。

In situ LA-ICPMS U-Pb dating of ore-stage carbonate minerals could be applied to constrain the age of mineralization, thus providing significant insight into ore genesis. The dominated industry orebodies of the Xitieshan Pb-Zn deposit are non-laminated orebodies hosted in marble, which might be formed by late-stage hydrothermal superimposition after the metamorphism and deformation of the wall rocks, Tanjianshan Group. Hydrothermal carbonates including calcite, ankerite, siderite and dolomite were also formed during the mineralization of non-laminated orebodies. This proposed project will apply the LA-ICPMS U-Pb dating methods to ore-stage hydrothermal carbonates to date the mineralization of non-laminated orebodies, and further find out the possible links between the hydrothermal superimposition and regional tectonic, magmatic or hydrothermal events. C, O and in situ Sr isotopic compositions of hydrothermal carbonates and marble also will be analyzed. The analysis results in combination with the age data will be employed to study the source of ore-forming fluids, fluid-rock interaction, and hence the metallogenic mechanism of non-laminated orebodies in the Xitieshan deposit.