四川盆地三叠系深层富钾卤水赋存区带预测

发布时间：2018-06-27 02:19

本文选题：四川盆地 + 富钾卤水　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：钾资源是重要的工业、农业资源,我国钾资源用量大,开采深层地下富钾卤水有利于缓解我国钾资源匮乏的现状。四川盆地地下卤水资源丰富,开采历史悠久,在平落坝等地区的三叠系已经发现富钾卤水。本文以四川盆地中三叠统雷口坡组为研究对象,分析盆地主要成卤期古板块位置、构造带发育、沉积演化等,就四川盆地富钾卤水的形成、运移、富集等方面进行探讨,综合地质、构造、水文等控制储卤构造形成的要素,对四川盆地富钾卤水有利区带的分布做了预测。四川盆地沉积基底形成时间早于震旦纪,震旦系及之后的盖层发育较为全面,保留较为完整。利用欧拉极数据,还原古板块位置,四川盆地所处的华南古板块在三叠纪时期处于低纬度带,气候炎热,有利于古盐盆发育。三叠纪之后,四川盆地所处的华南板块逐渐向现今位置漂移,并经历多期构造运动的改造,其中燕山Ⅰ期运动最具代表性,造就了四川盆地如今主要的构造格局。断裂带与褶皱带作为四川盆地广泛发育的构造,对于盆地卤水富集有着重要的控制作用。目前已在盆地的多个深大断裂带,及根据褶皱带发育情况而划分出的三个主要构造区域:川东南褶皱坳陷区、川中隆起区以及川西北坳陷区,发现多个钾异常点。四川盆地三叠系深层卤水中K+的来源除海水为主要还包括:生物来源及火山岩来源。K+与Na+同为盆地三叠系深层卤水中最常见的阳离子类型,然而两者在不同环境下的沉积过程又存在差异性,在生物活动影响下,Na、K元素重量比值可由水圈中的1:0.03变为生物圈中的0.02:0.3,因此适宜生物生存的三叠纪时期可能因为生物的影响提供了K+;雷口坡组一段底部发育的的绿豆岩(含硅质豆粒的富钾伊利石粘土岩,一种变质火山岩类型)中较高的K+含量(6.37%)也可能是K+的来源之一。运用Arc Gis软件的栅格分析功能,综合地层厚度、构造带展布等,并对比盆地同期古盐盆发育情况,预测四川盆地富钾卤水有利区带包括:1.云阳奉节褶皱带;2.雅安以北平落坝断层褶皱带;3.成都以南、简阳以西深大断裂带;4.乐山以北、眉山以西断层带;5.南充—营山褶皱带;6.威远—自贡—绥江褶皱带;7.苍溪、巴中断层褶皱带;8.达州断层褶皱带。
[Abstract]:Potassium resource is an important industrial and agricultural resource in China. The exploitation of deep underground rich potassium brine is helpful to alleviate the present situation of potassium resource shortage in China. Sichuan Basin is rich in underground brine resources and has a long history of exploitation. Potassium rich brine has been found in Triassic system in Pingluoba and other areas. Taking the Laikoupo formation of the Middle Triassic in Sichuan Basin as the object of study, this paper analyzes the location of paleo-plate, the development of tectonic belt and sedimentary evolution in the main halogenation period of the basin, and discusses the formation, migration and enrichment of potash rich brines in Sichuan Basin. The distribution of the favorable zone of rich potassium brine in Sichuan basin is predicted by synthesizing the factors of geology, structure and hydrology controlling the formation of halogen structure. The sedimentary basement in Sichuan basin was formed earlier than the Sinian period, and the caprock of the Sinian system and its aftermath developed completely and remained relatively intact. Based on the Euler pole data and the reduction of paleo-plate position, the South China paleo-plate in Sichuan Basin was located in the low latitude zone during the Triassic period, and the climate was hot, which was beneficial to the development of paleosalite basin. After the Triassic, the South China plate in Sichuan Basin gradually drifted to the present position, and experienced the transformation of multiple tectonic movements, among which Yanshanian stage I movement was the most representative, which formed the main tectonic pattern of Sichuan Basin today. As a widely developed structure in Sichuan Basin, fault zones and fold zones play an important role in controlling the brine enrichment in the basin. At present, many K anomalies have been found in several deep fault zones in the basin and three main tectonic regions, namely, the southeast Sichuan fold depression, the central Sichuan uplift and the northwestern Sichuan depression, which are divided into three main structural regions according to the development of the fold belt. The source of K in the Triassic deep brine in Sichuan Basin mainly includes: biological source and volcanic rock source. K and Na are the most common cationic types in the Triassic deep brine of the basin. However, there are differences in the deposition process between the two in different environments. Under the influence of biological activities, the weight ratio of Na + K can be changed from 1: 0.03 in the hydrosphere to 0.02: 0.3 in the biosphere. The higher K content (6.37%) in the mung peas (K-rich Illite claystone, a type of metamorphic volcanic rock) developed at the bottom of the first member of the Leicoupo formation may also be one of the sources of K. Using the raster analysis function of Arc Gis software, synthesizing the formation thickness and the distribution of the tectonic belt, and comparing the development of the paleo-salt basin in the same period of the basin, it is predicted that the favorable zone of rich potassium brine in the Sichuan basin includes 1: 1. Yunyang Fengjie fold belt 2. The fault fold belt of Luoba in Beiping, Ya'an, China is 3. To the south of Chengdu and to the west of Jianyang, the deep fault zone is no. 4. Leshan north, west of Meishan fault belt 5. Nanchong-Yingshan fold belt 6. Weiyuan-Zigong-Suijiang fold belt 7. Cangxi, Bazhong fault fold belt, No. 8. Dazhou fault fold zone.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P619.211

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