柴达木盆地深层地下卤水战略性资源成盐元素富集模式研究

As national strategic resources, K、B、Li、Rb、Cs、Sr are enrichment in the deep underground brine of Qaidam basin, which is represented by Tertiary oil field water. However，the research level of it is low. Based on previous study we found that the resources highly enriched characteristic of the brine not only related to deep origin but also comes from the leaching process of mineral and rock during the salify era. According to this conclusion, we want to further study the relationship of deep origin and strategic resources in the brine with the research of strontium, lithium isotope. At the same time, leaching experiments will be used in this study in order to reveal the strategic elements precipitate and migration patterns during the weathering leaching effect. Further more discuss the contribution rate of surrounding hills and salt system to the enrichment of strategic resources. At the last, establish the enrichment model of strategic resources in the deep underground brine of Qaidam basin by PHREEQC. The study will be provide important scientific support for the deep brine resources sustainable utilization and the next step of efficient resources exploration of Qaidam basin.

柴达木盆地深层地下卤水富含K、B、Li、Rb、Cs、Sr等国家战略性资源，目前发现的深层卤水以柴达木盆地西部第三系油田水为主，是继第四纪盐湖之后又一盐类资源富集区，但目前研究程度较低。我们通过水化学和同位素地球化学前期研究表明：深层地下卤水资源富集的特征可能同时受控于深源流体和成盐期周围山体与含盐系地层风化淋滤作用。针对这一结论，本次研究拟通过锶、锂同位素进一步探讨深源流体与深层卤水资源富集的关系，同时开展淋滤实验以揭示风化淋滤作用过程中战略性元素析出和迁移规律，研究成盐期周围山体与含盐系地层岩矿对战略性元素富集的贡献率，通过PHREEQC软件模拟来定量建立柴达木盆地深层卤水战略性元素富集模型。此项研究将对柴达木盆地深层卤水资源的高效可持续开发利用和下一步资源勘探提供重要科学支撑。

本研究通过锶、锂同位素进一步探讨深源流体与深层卤水资源富集的关系，同时开展淋滤实验以揭示风化淋滤作用过程中战略性元素析出和迁移规律，研究成盐期周围山体与含盐系地层岩矿对战略性元素富集的贡献率，通过PHREEQC软件模拟来定量建立柴达木盆地深层卤水战略性元素富集模型。为柴达木盆地深层卤水资源的高效可持续开发利用和下一步资源勘探提供重要科学支撑。. 通过周围山系岩石和地层泥岩沉积物的成盐元素分析，与深层卤水的战略性成盐元素展开对比，还开展淋滤实验获得了成盐元素的迁出规律，结合锶和锂同位素，确认了深源流体的贡献，并利用软件模拟计算得出其贡献率为10%。柴达木盆地深层地下卤水的战略性资源的大量富集与柴达木盆地古大湖有关，古大湖经受蒸发堆积了巨量的碳酸盐，同时古湖水经历浓缩将大量的有益矿种元素进一步富集，经受造山带隆升过程中风化剥蚀物质堆积以及构造推覆等作用，沉积于地层中，这是深层地下卤水成盐元素富集的基础。青藏高原碰撞以来，使得柴达木盆地深大断裂进一步发育，新构造运动频繁，后碰撞效应使得部分地壳物质继续熔融，深大断裂则沟通了大气降水与岩浆房等热源，经历深循环，下潜过程中一方面溶滤了大量成盐元素，另一方面接受深源流体地热水的直接补给，携带大量的战略性元素上涌补给到储层中，进一步溶蚀储层，溶出成盐元素，最终形成富含战略性元素的深层地下卤水。