江西省吉泰盆地南洲含锂卤水矿床地质特征及成因探讨

Geological Characteristics and Genesis of Nanzhou Lithium Brine Deposit in Jitai Basin,Jiangxi Province

为查明南洲含锂卤水矿床地质特征及成因,通过样品分析测试、化学指数计算和查阅区域地质资料分析矿区卤水水化学特征、构造条件、古地理环境和物质来源。研究表明,南洲含锂卤水矿床赋存于周田组第三段层间滑脱构造的次级裂隙中,其矿化度平均值292.8 g/L,NaCl平均含量23.3%,LiCl平均含量627.41 mg/L,为富锂氯化钠型卤水;卤水钠氯系数平均值0.96,氯溴系数平均值33.45,脱硫系数平均值0.28,钙镁系数平均值2.76,反映了卤水形成时间较长、封闭性较好、具溶滤型卤水特征;卤水形成于封闭—半封闭的地貌环境和干燥的气候条件,成矿物质来源于盆外火成岩的风化产物和深源卤水,成因类型为氯化钙型水。在矿区南东方向的新圩坳陷具有探寻类似南洲、梅岗型含锂卤水矿的潜力。

In order to find out the geological characteristics and genesis of Nanzhou lithium-bearing brine deposit,the brine chemical characteristics,structural conditions,paleogeographic environment and material source in the mining area are analyzed through sample analysis and test,chemical index calculation and regional geology.The research shows that the Nanzhou brine deposit occurs in the secondary fissure of the interlayer detachment structure in the third member of Zhoutian formation.Its average salinity is 292.8 g/L,the average content of NaCl is 23.3%,and the average content of LiCl is 627.41 mg/L.It is a lithium rich sodium chloride brine.The average value of sodium chloride coefficient of brine is 0.96,the average value of chlorine bromine coefficient is 33.45,the average value of desulfurization coefficient is 0.28,and the average value of calcium magnesium coefficient is 2.76,which reflects the characteristics of long brine formation time,good sealing and leaching brine.The brine is formed in a closed-semi closed geomorphic environment and dry climatic conditions.The ore-forming material comes from the weathering products of igneous rocks outside the basin and deep source brine.The genetic type is calcium chloride water.Xinwei depression in the southeast direction of the mining area has the potential to explore lithium bearing brine deposits similar to Nanzhou and Meigang types.