马海盆地深部孔隙卤水矿床水化学特征及成因

通过数理统计、聚类以及离子特征系数等分析方法,对柴达木马海盆地的深部砂砾石层孔隙卤水水化学特征进行了分析。卤水离子浓度空间分布特征表现为pH、Cl^-、TDS和Na+浓度值变化范围较小,分布均匀,而K^+、Rb^+以及Br^-、Mg^2+、Li^+、Sr^2+、I^-、B2O3、Ca^2+、Cs^+、NO3^-、SO4^2-等离子浓度分布不均匀,差异显著;Cl^-、TDS、Na^+、K^+、Mg^2+和Li^+与SO4^2-聚为一个亚类,表明卤水演化过程中有酸性液体的参与;K^+含量自西向东有增大的趋势,与Mg^2+和Li^+的变化具有相关性;离子特征系数反映出蒸发残余及盐岩溶解的多源性特征。研究区水化学类型为单一的氯化钠型,这种单一的物源可能与推测的更新统下伏盐岩层有关。

Hydrochemical Characteristics and Origin of Deep Pore Brine Deposits in Mahai Baisn

Analysis of the hydrochemical characteristics and origin of deep sandy gravel brine in Mahai Basin is based on mathematical statistics, cluster analysis, and ion characteristic coefficients. The spatial distribution characteristics of brine ion concentrations shows that the ion concentrations of pH, Cl-, TDS, and Na+ have a narrow range of change and uniform distribution, while the ion concentrations of K+, Rb+, Br-, Mg2+, Li+, Sr2+, I-, B₂O₃, Ca2+, Cs+, NO₃-, and SO₄2- exhibit significant variation and uneven distribution. Cluster analysis indicates that Cl-, TDS, Na+, K+, Mg2+, Li+, and SO₄2- piled, which shows the evolution of brine is related to the joining of acid liquid. K+, which has correlation with Mg2+ and Li+, shows an increasing trend from west to east in the variety graph of ion contents. The characteristic coefficients and higher contents of trace ions suggest that the brine has multifocal features of evaporation residue and gypsum dissolution. The Na+, K+, and Mg2+//Cl--H₂O four-element system mesostationary phase, as well as the analysis of ionic characteristic coefficients in brine, indicate that the hydrochemical type is the single chloride-type, which reflects the single provenance and may have a relationship with the stochastic underlying salt strata of the Pleistocene.