基于矿物组成分析的昆特依盐湖杂卤石成因解析——以大盐滩矿区ZK3608孔为例

昆特依盐湖杂卤石储量丰富,是研究陆相成因杂卤石的良好载体。对研究区ZK3608钻孔剖面进行矿物学分析,尝试从矿物组成及组合变化的角度揭示杂卤石的形成过程和机制。XRD结果表明,剖面中主要盐类矿物为石盐、石膏和杂卤石,此外还检测到六水泻盐、芒硝、无水芒硝、钾石盐、钾芒硝、菱镁矿等矿物。矿物组合及其剖面变化特征揭示,盐层中的杂卤石以原生沉积为主,碎屑层中多数杂卤石可能为交代成因。沉积环境分析表明,盐类沉积为干冷的偏酸性氧化环境,碎屑沉积为相对温湿的偏碱性还原环境。

Genesis of Polyhalite in Kunteyi Salt Lake Based on Mineralogical Analysis——Taking ZK3608 Borehole in Dayantan Mining Area as An Example

Kunteyi Salt Lake is rich in polyhalite, which makes it a good carrier for studying continental polyhalite. Based on mineralogical analysis of ZK3608 core in the study area, this study attempts to reveal the formation process and mechanism of polyhalite from the perspectives of mineral composition and assemblage changes. The X-Ray diffraction results show that the main salt minerals in the profile include halite, gypsum and polyhalite. In addition, salt minerals such as hexahydrite, mirabilite, thenardite, sylvite, aphthitalite and magnesite were also detected. The mineral assemblages and their variation with depth reveal that the polyhalites in salt beds are mainly primary deposits, and the most polyhalites in clastic layers are possibly secondary origin. Sedimentary environment analysis shows that the salt deposits reflected a dry and cold acidic oxidized brine environment, while the debris deposits are formed in a relatively warm and humid alkaline reductive environment.