塔里木盆地西部卤水地球化学特征及成钾远景预测

在塔里木盆地的地质发展史上，尤其是在白垩纪和第三纪，经历了多次新特提斯海的海进和海退，带来了大量成盐物质，再加上后期持续干旱的气候条件和适宜的岩相古地理条件，使塔里木盆地沉积了一套厚层石盐岩、膏泥岩、碳酸盐岩以及泥质岩等，为钾盐资源的形成奠定了一定物质基础，同时由于受地质构造和中生代盆地断裂的控制所形成的若干次级盆地，加上适宜的古地理环境，使其具备了钾盐矿床形成的基本条件。通过野外实地考察取样，采集岩盐及卤水样品共300多件，用于实验分析的共142件（卤水43件）。通过对塔里木盆地西部卤水的地球化学特征分析，讨论了寻找钾盐的直接指标K+含量和各种地球化学特征系数，探讨了塔里木盆地的成盐模式、卤水浓缩阶段和成钾可能性，得出:塔里木盆地的钾盐远景区是喀什凹陷和阳霞凹陷；依据溴和硼含量以及各种特征系数值与正常卤水浓缩值比较，可知塔里木盆地是溴和硼等微量元素含量较少的地区，不能完全依靠这些特征参数来判断塔里木盆地的卤水浓缩程度和钾盐资源状况，同时也说明了塔里木盆地是一个成盐环境相对比较复杂的地区。

Geochemical Characteristics on Brine and Potash Perspective in the Western Tarim Basin

In the geological evolution of Tarim Basin,many transgressions and regressions of the ancient Terishappened,especially in the Cretaceous and Tertiaryperiod,and broughtplentyof salt sources.What's more,because of uttermost drought and proper sedimentary facies and paleogeography,many salt,gypsum,carbonate and mud-salt weredeposited.By our fieldwork,above 300 samples were collected including brine and solid.Among these samples,43 brine samples and 99 solid halite samples were analyzed.The item of analysis included K~( ),Na~( ),Ca~(2 ),Mg~(2 ),Cl~(-),SO~(2-)_4,CO~(2-)_3,HCO~-_3,Br~(-),B~(3 )and so on.This paper discussed the variety of the content of K~( )and the characteristicscoefficients of geochemistry,the model of salt formation,the concentration stage of brine and the possibility of potash formation by geochemical analysis of the brine from Tarim Basin.In the end,the potash perspectivewas proposed.From the geochemical parametersof brine in WesternTarim Basin,we could conclude that the perspective of potashis Kashi Sag and Yangxia Sag.By comparing the content of microelementand the geochemical parametersof brine with that of normal condensed brine,it is known that there is little microelementssuch as Br and B in Tarim Basin,so we could not completely depend on these indexes to judge the condense stage of brine and halite as well as potashresources,and this viewpoint indicates that Tarim Basin is the intricate area of salt formation.