兰坪-思茅盆地水化学特征及找钾指标探讨

文章对兰坪-思茅盆地水(主要是盐泉水)的化学特征、离子比值进行了研究,探讨了找钾指标。收集文献资料,获得思茅地区217件矿化度大于3 g/L盐泉水样数据,并通过野外考察和采样分析获得兰坪-思茅盆地25件水样数据。该区盐泉水的矿化度范围3.026~316.526 g/L,盐泉水p H值范围5.3~9.2;化学类型主要为硫酸钠亚型(占54.19%,n=217),其次为碳酸盐型(占17.73%),对找钾有利的氯化物型和硫酸镁亚型盐泉水分别占14.29%和13.79%;钾盐系数和溴氯系数最高值分别为18.520和14.470。通过对背景值的统计分析,确定了盐泉水的水化学组分和离子比值异常阈值。综合分析研究区盐泉水的水化学组分和特征系数分布图,初步认为在兰坪盆地内景谷—宁洱一带及周边和磨铺—宝藏(勐野井)—二官寨一带及周边均具有找钾潜力。

Hydrochemical characteristics and potassium-prospecting indicators of Lanping-Simao Basin, Yunnan Province

In this paper, hydrochemical characteristics and ionic ratios (mainly for saline springs) in the Lanping-Simao Basin of Yunnan Province were investigated and indicators based on ionic ratios were studied for potassium deposit prognosis. Analytical data of 217 saline spring samples (TDS>3 g/L) collected from available reference materials and 25 water samples from field work were analyzed. TDS values of saline spring waters from the Lanping-Simao Basin range from 3.026 g/L to 316.526 g/L,and their pH values range from 5.3 to 9.2. According to the Valyaskko's classification, saline spring waters in the study area mainly belong to the sodium sulfate type (accounting for 54.19%, n=217), followed by the carbonate type (accounting for 17.73%), the chloride type (accounting for 14.29%) and the magnesium sulfate type (accounting for 13.79%). Threshold values of chemical components and ionic ratios for saline springs were determined based on statistic analysis of their background values. According to distribution of water chemical components and ionic ratios, the Jinggu-Ninger area and the Mopu-Baozang (Mengyejing)-Erguanzhai area are considered to be more favorable for potassium exploration in the Simao Basin.