东秦岭南泥湖-三道庄Mo-W矿床钨成矿作用:矿物学和元素地球化学研究

Eastern Qinling metallogenic belt, not only has the huge reserves of molybdenum, the associated tungsten deposits are also in large-superlarge scale (e.g. Nannihu-Sandaozhuang deposit and Yechangping deposit, and Shangfanggou deposit). Because of the fine tungsten particles and difficult mining properties, the occurrence and mineralization of tungsten has not been very good attentioned. Here, we studied the Nannihu-Sandaozhuang Mo-W deposit, including a systematic study on analyzing the geological characteristic of the deposit and detailed division of metallogenic stages. Identified tungsten minerals and W content of gangue and ore minerals by Electron Probe microanalysis and LA-ICP-MS. Trace element ,REE element and Sm-Nd isotopic dating in scheelite were conducted to determine the features of hydrothermal fluid and the mineralization epoc. According to the element evolution of molybdenum, we discussed the physical and chemical conditions difference between molybdenum and tungsten. This research not only provides the theory basis for the improvement of tungsten dressing technology, but also helps to recognize the metallogenesis of Eastern Qinling belt.

东秦岭多金属成矿带除钼资源储量巨大外，还伴生大型-超大型钨矿（如南泥湖-三道庄Mo-W矿床、夜长坪Mo-W矿床和上房沟Mo-W-Fe矿床）。但由于可见钨极少，同时受采选技术的限制，其赋存形式、成矿作用及其与钼矿化的关系一直缺乏合理的重视。本申请拟以南泥湖-三道庄斑岩-矽卡岩型Mo-W矿床为研究对象，在深入调查矿床地质特征的基础上，划分成矿期次与成矿阶段，确定辉钼矿和白钨矿共生矿物组合特征及其空间分布关系，采用电子探针分析（EPMA）和激光剥蚀电感耦合质谱（LA-ICP-MS）等研究手段，查明主量和微量W元素的赋存形式，通过测定矿床中白钨矿主、微量和稀土元素含量，研究其微量元素、稀土配分特征和Sm-Nd同位素年龄，确定白钨矿成矿流体特征和成矿时代，对比钼矿成矿作用，厘定成矿作用过程中W、Mo矿化关系。本次研究不仅为矿区完善钨选矿工艺提供理论依据，同时为全面认识东秦岭地区多金属矿床奠定基础

东秦岭多金属成矿带是我国重要的钨金属产出地之一（如南泥湖-三道庄Mo-W矿床、夜长坪Mo-W矿床和上房沟Mo-W-Fe矿床）。本次以南泥湖-三道庄斑岩-矽卡岩型Mo-W矿床为研究对象，在深入调查矿床地质特征的基础上，划分成矿期次与成矿阶段，确定辉钼矿和白钨矿共生矿物组合特征及其空间分布关系，矿床内含钨矿物主要为白钨矿，白钨矿主要赋存于矽卡岩及钙硅酸角岩中,且矽卡岩高于钙硅酸角岩，矿区存在3种石榴子石，自形粒状，半自形粒状和细脉状，根据不同石榴子石元素分布特征，确定与钨有关的流体演化过程。