投稿时间：2011-08-05
修订日期：2012-02-28
中文摘要:利用测井、录井、岩芯、薄片、扫描电镜及能谱分析等资料,综合研究川西地区雷口坡组岩相古地理、分析富钾卤水成因并预测有利分布区带。川西地区中三叠统雷口坡组发育蒸发台地相、局限台地相和开阔台地相。地层年代从古到新可分为雷一至雷五共5期,海平面经历了2次变浅→加深的旋回,雷四1期由于快速海退,广泛发育蒸发台地相,其中成都地区膏盆内发育平落坝、盐井沟及大兴场3个盐盆。认为川西地区雷口坡组富钾卤水是由海水蒸发浓缩而成的海相原生沉积含钾卤水,在晶间卤水、钾盐类溶滤水和陆相径流来源卤水的掺合下,发生高度变质作用而形成的混合型水。富钾卤水遵循"膏盆-盐盆控区、褶皱-断层定带、裂缝-孔隙储卤"的分布特征。在沉积相、岩相古地理、富钾卤水来源与分布特征等综合研究的基础上,提出了"卤水聚钾中心"和"储卤中心"的概念,结合单井卤水层水化学分析数据与富钾卤水的工业开采指标,在川西地区雷口坡组圈定并预测出1个卤水聚钾中心和3个储卤中心;卤水聚钾中心位于平落坝构造区,储卤中心分别位于江油中坝、丹棱大兴场以及彭山盐井沟构造区,可为四川盆地中三叠统雷口坡组富钾卤水的勘探指明方向。
Abstract:Based on the data of well logging, compound logging, core, thin section, SEM and energy spectrum analysis, the authors made a comprehensive study of lithofacies palaeogeography of western Sichuan basin, analyzed the origin of potassium-rich brine and forecast the promising areas.The sedimentary facies are composed of evaporate platform, restricted platform and open platform facies in the Middle Triassic Leikoupo Formation in western Sichuan basin. The sea water of Leikoupo spanned two evolutionary processes from regression to transgression during 1st-5th stages. And during 41th stage, with the rapid regression, evaporate platform deposits were produced in several areas. Chengdu gypsum-basin micro-facies include 3 salt-basin micro-facies, which are called Pingluoba, Daxingchang and Yanjinggou salt-basin respectively. The potassium-rich brine in western Sichuan basin is a mixed high-degree metamorphic brine, which suggests that the sea facies primary sedimentary potassium brine from the evaporation and concentration of sea water became mature by inter-crystalline brine, brine from dissolution and infiltration reaction between potassium saline minerals and brine from continental flow. In addition, the distribution characteristics of the potassium-rich brine can be generalized into "gypsum-basin and salt-basin control the area, folds and faults determine the zone, and cracks and pores store the brine". Based on a comprehensive analysis of sedimentary facies, lithofacies palaeogeography and the origin and distribution characteristics of potassium-rich brine in western Sichuan basin, the authors put forward two concepts which are called "brine aggregate-potash center" and "brine reservoir center". According to the single well water chemical analytical data of brine formation and standard industrial production indices of rich potassium brine,one aggregate-potash center and three rich-halogen centers were delineated and predicted in western Sichuan basin, with the aggregate-potash center located in Pingluoba structure area, and the rich-halogen centers located respectively in Jiangyou Zhongba, Danling Daxingchang and Pengshan Yanjinggou structure areas,which indicate the direction for exploring rich potassium brine in the Middle Triassic Leikoupo Formation in western Sichuan basin.
keywords:geology lithofacies palaeogeography potassium-rich brine brine aggregate-potash center brine reservoir center Middle Triassic Leikoupo Formation western Sichuan basin
文章编号：
中图分类号：P619.21+1
文献标志码：
基金项目:本文得到国家地质调查项目油钾兼探实施方案和调查评价综合研究(1212011085524)和四川三叠纪富钾卤水富集规律及有利地区调查评价(1212010011803)的联合资助
引用文本：
徐国盛,陈美玲,刘为,孟昱璋,杨朋,胡永宏,彭敬成,王宪刚,黄小琼.2012.川西地区雷口坡组岩相古地理与富钾卤水预测[J].矿床地质,31(2):309~322XU GuoSheng,CHEN MeiLing,LIU Wei,MENG YuZhang,YANG Peng,HU YongHong,PENG JingCheng,WANG XianGang,HUANG XiaoQiong.2012.Lithofacies palaeogeography and forecast of potassium-rich brine of Leikoupo Formation in western Sichuan[J].Mineral Deposits31(2):309~322
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