重庆地区早中三叠世主要成盐盆地海相钾盐找钾潜力分析

Potash-prospecting Potential Analysis of Early-Middle Triassic Marine Potash in Chongqing Main Salt-Forming Basins

中文关键词:  重庆地区  海相钾盐  找钾潜力  早中三叠世

英文关键词:Chongqing area  Marine potash  Potassium-prospecting potential  Early-Middle Triassic

中文摘要:

      重庆地区是我国古代海相钾盐找矿的重要区域，但一直未取得找矿突破。本文对合川盐盆、长寿-垫江盐盆、忠县盐盆、万县盐盆等主要成盐区含盐地层找钾潜力进行了分析。系统收集了区内盐矿勘查成果，补充测试了合川、长寿、垫江等地区三叠系岩盐样品。结果显示，长寿-垫江盐盆三叠系岩盐中存在原生杂卤石矿物，K+含量达到3.82%，合川盐盆岩盐样品中也存在原生杂卤石矿物，K+含量达到3.71%，忠县盐盆和万州盐盆岩盐钾含量较低，未发现含钾矿物。长寿-垫江盐盆古卤水浓缩程度较高，大部分样品溴氯系数显示达到钾石盐析出阶段，其次为合川盐盆，忠县和万州盐盆古卤水浓缩程度较低，主要在岩盐析出阶段。综合分析认为早中三叠世时期，重庆地区古气候炎热，古卤水浓缩程度较高，长寿-垫江盐盆内次级凹陷，具有较好的找钾潜力。

英文摘要:

      Chongqing region is one of important areas for the exploration of ancient marine potash deposit in China, but no significant breakthroughs have been made in this field. This paper analyzed the potential for potash formation in the salt-bearing strata of the main salt-bearing areas such as the Hechuan Salt Basin, Changshou-Dianjiang Salt Basin, Zhongxian Salt Basin and Wanxian Salt Basin. This paper systematically collected the mine exploration results of Chongqing region, and some salt samples from Hechuan, Changshou and Dianjiang were obtained and tested. Results show that there are primary polyhalite minerals in the Triassic rock salt of Changshou-Dianjiang Salt Basin, with K+ content reaching 3.82%. There are also primary polyhalite minerals in the rock salt samples of Hechuan Salt Basin, with K+ content reaching 3.71%. In the Zhongxian Salt Basin and Wanxian Salt Basin, potassium contents are low and no potassium minerals are present. The concentration of ancient brine in Changshou-Dianjiang Salt Basin is high, and ratios of bromine (Br)?and chlorine(Cl) of most samples show that they have reached the stage of potassium salt mineral precipitation, followed by the Hechuan Salt Basin. The Br concentration in Zhongxian and Wanxian Salt Basin is low, mainly at the stage of rock salt precipitation. The comprehensive analysis shows that Chongqing area has a good potassium formation conditions in the early and Middle Triassic with hot paleoclimate and high concentration of ancient brine. The sub-depression areas in Changshou-Dianjiang Salt Basin has preferable potash-prospecting potential.