西秦岭地区西成盆地铅锌矿床成矿流体特征研究

The fluid inclusion study is becoming an increasingly important means of studying ore genesis, it provides basis information of ore-forming fluid nature, migrating and precipitation mechanisms of metallic elements. In the previous work, research of fluid inclusions mainly focused gangue minerals ore minerals which is intergrowth with ore minerals, so as to infer the nature of the ore-forming fluids, such an approach sometimes one-sided, because the deposits of certain epigenetic gangue minerals may record the whole process of fluid evolution of the mining area, it is difficult to distinguish between the ore-forming fluids and non-ore-forming fluid which is trapped in fluid inclusions, hence that the research on fluid inclusions in opaque ore minerals by means of infrared microthermometry is very necessary. Xicheng basin is one of the most important ore field in the the Qinling Pb-Zn mineralization belt. The ore genesis of the Pb-Zn deposit in Xicheng basin is still in controversy, there are two different views of the "synenetic" and "epigenetic". The research on fluid inclusions in the opaque ore mineral will be conducted in this project, combined with research of fluid inclusions in the gangue minerals and geochemical analysis, aiming to understand the genetic mechanism of deposit formation and the coupling relationship of ore formation and tectonic evolution.

流体包裹体研究已日益成为矿床成因研究的重要手段，它为了解矿床成矿流体性质以及成矿元素迁移、沉淀的机制提供了重要的依据。前人的工作多侧重于研究与矿石矿物相伴生的脉石矿物中的流体包裹体，并据此推测成矿流体的性质，这样的方法难免有些片面，因为在某些后生矿床中，脉石矿物可能记录了矿区流体演化的整个过程，这给区分成矿流体与非成矿流体带来困难，此时对不透明的矿石矿物中的流体包裹体直接进行红外显微测温研究显得十分必要。西成矿田是秦岭铅锌成矿带内最为重要的矿田，目前对区内铅锌矿床的成因仍存在"同生"与"后生"两种不同的观点。本次工作通过对矿区内主要矿床的矿石矿物中的流体包裹体进红外显微测温研究，同时对脉石矿物中的包裹体开展对比研究，结合包裹体成分及岩石地球化学分析，从而了解矿区内主要矿床的成因机制以及矿床形成与构造演化的耦合关系。

秦岭铅锌成矿带是我国最重要的铅锌成矿带之一，其中的西成矿田产出厂坝-李家沟、毕家山、邓家山、洛坝等四处大型矿床，是成矿带内最重要的矿田。本次对毕家山矿床、洛坝矿床及周边的代家庄铅锌矿开展了成矿物质来源研究、流体包裹体研究、流体来源研究工作，对西成盆地内沉积岩容矿的铅锌矿床的成矿流体演化特征及其与矿床形成过程之间的耦合关系进行总结。