江南过渡带桂林郑富钼白钨矿矿床的成因研究

矽卡岩钨矿床中形成超常富钼白钨矿（MoO3>48.63 wt.%）的岩浆-热液条件尚不清楚。基于前期发现江南过渡带地区桂林郑矿床白钨矿超常富钼（8.97~ 70.68 wt.% MoO3）的地质事实，本申请拟以桂林郑矿床为主要研究对象，通过详细的野外地质调查和室内研究，并结合精细矿物学、流体包裹体、同位素地球化学等现代分析手段，查明桂林郑矿床不同期次白钨矿的矿物成分、成矿流体组成与理化性质，查明各期次成矿流体来源与性质及其对白钨矿钼含量的影响。通过开展桂林郑矿床成矿岩体与区内产出贫钼白钨矿矿床（高家塝、百丈岩等）成矿岩体的地质与地球化学特征对比研究，建立形成富钼白钨矿对应岩浆岩的成因及成矿专属性指标。本次研究成果有望揭示富钼白钨矿形成的岩浆-热液条件，深化矽卡岩富钼白钨矿矿床的成因认识，为研究区成矿规律与找矿预测提供科学依据。

The magmatic-hydrothermal conditions related to formation of Mo-rich scheelite (MoO3>48.63 wt. %) in tungsten deposit is still unclear. We have shown that the MoO3 contents of scheelite grains from Guilinzheng deposit are between 8.97 wt. % and 70.68 wt. %, and they appear to have formed during the magmatic- hydrothermal mineralization process. In this study, we aim to elucidate the genesis of abnormally Mo-rich scheelite, using Guilinzheng tungsten-polymetallic deposit as the main focus of the research. After detailed field geology and petrographic study of Guilinzheng ore deposit, we firstly clarify the forming stages of the scheelite with other contemporaneous minerals. Based on targeted geochemical analysis of the selected samples from different ore-forming stages, including mineral and whole rock geochemistry, fluid inclusion, and isotope geochemistry, we further find out the compositions and physicochemical properties of the ore-forming fluids in different stages and certify its constraints to Mo-rich scheelite. Furthermore, we will carry out a systematic geological and geochemical comparison between the mineralization-related intrusions at Guilinzheng and at Mo-poor scheelite (MoO3 <5.18 wt. %) W deposits (Gaojiabang and Baizhangyan). This will be used to constraining the genesis and ore-forming conditions at the Guilingzheng intrusion that resulted in the abnormally Mo-rich scheelite. This research is expected to reveal the specific magmatic-hydrothermal conditions that resulted in formation of the abnormally Mo-rich scheelite, which will improve our understanding of how tungsten polymetallic skarn deposits form, and will improve understanding of where tungsten polymetallic deposits are likely to occur in the study area.