【摘要】 库车盆地古近系—新近系发育一套巨厚的膏岩盐层,钻探勘查显示,在拜城凹陷南缘5100 m深古近系库姆格列木群地层中发现钾石盐矿物。本研究采集并分析了多件盐泉水化学组成,结果显示7件盐泉水矿化度在117.7～299.4 g/L之间,钾含量在15.25～45.68 g/L之间,明显富钾,是以往报道数据（低于1 g/L）的几十倍,属于新疆首次发现。根据水化学分类,富钾盐泉水以氯化物型水为主,是Ca-Cl型卤泉水;水化学特征系数表明泉水具有高K×10³/Cl和nK/nBr值、低的nMg/nCl和Br×10³/Cl值（nCl^-=nNa⁺+nK⁺）特征。同时,盐泉水均落在25℃Na⁺, K⁺,Mg²⁺//Cl^-,SO■-H₂O五元水盐体系钾石盐相区,说明盐泉水可能溶滤了地层中的钾石盐,且受强烈构造挤压,沿地层断裂带或裂隙通道出露地表。库车盆地富钾盐泉水的发现,是新疆库车盆地含盐系地层存在固体钾盐的初步证据,对钾盐勘查的重点远景区具有重要的指示意义。更多还原

【Abstract】 One suite of thick gypsum and halite layers was discovered to occur in the Paleogene-Neogene strata, Kuqa basin, Xinjiang. Exploration and study results show that sylvite deposits developed at the depth of 5100 m in the southern margin of Baicheng depression during Paleogene. Several samples of saline spring waters from the Kuqa basin were analyzed in 2015～2016. The results indicate that seven samples have higher total dissolved solution（TDS）（117.7 to 299.4 g/L） and distinctly enriched in K⁺（from 15.25 to 45.68 g/L）, which is several tens of time more than previous reported data（<1.0 g/L）. High K⁺ concentrations in the spring waters are the first report in the Kuqa Basin at present. The hydrochemical classification indicates that these spring waters are dominantly chloride-type waters and belong to Ca-Cl spring brines. The ratios of hydrochemical characteristics（such as K×10³/Cl, nNa/nCl, nMg/nCl, Br×10³/Cl and nK/nBr） of potassium-rich spring waters show that they have high K×10³/Cl and nK/nBr, low nMg/nCl and Br×10³/Cl, and nCl^-=nNa⁺+nK⁺. Meanwhile, these potassium-rich spring waters are also plotted into sylvite phase’s area in Na⁺, K⁺, Mg²⁺//Cl^-, SO■-H₂O quinary metastable phase diagram of salt-water system at 25℃. These comparisons imply that these spring waters might leach sylvite from deep strata, and discharged and seeped along fault zones under strong tectonic compression circumstance. The discovery of these potassium-rich spring waters in the Kuqa Basin, Xinjiang demonstrates that potash deposits exist in the salt-bearing strata, and has important implications for exploration of potash deposits in this region.更多还原