摘要
老挝万象平原的钾镁盐矿主要赋存在塔贡组下段膏盐岩亚段(E1 tg1-1)中。经对6条实测剖面、53个钻孔的岩石组合、沉积构造、岩石特征、地层厚度分析,塔贡组下段(E1 tg1)岩相古地理具如下特征:①含钾地层可划分为半深湖亚相、浅湖亚相、滨湖亚相、湖泊三角洲亚相。滨湖亚相可进一步划分出内带和外带;②钾镁盐矿产于半深湖亚相、浅湖亚相、湖泊三角洲亚相中,前者厚度较大;③万象成钾盆地为东深西浅的不对称盆地,盆地的古地理特征与现在的万象平原较为相似;④在沉积过程中,盆地基底由持续下降到逐步趋于稳定,卤水由逐步浓缩到迅速淡化,古气候由持续干燥炎热到湿热多雨,水体由弱还原向弱氧化环境变迁。
The Kalium-magnesium deposits in Vientiane plain of Laos mainly exist in the lower segment of Thangon and the subsegment of salt-gypsum beds（E1tg^1-1 ）. After the analysis of rock association, sedimentary structure, rock characteristics and the formation thickness of 6 measured geological profiles and 53 drilling holes, its paleogeography has followed features： （1）The potassium-bearing strata can be divided into four subphases, they are semi-deep lake, shallow lake, lakeshore, lake delta; and lakeshore subphase can be further divided into inner part and outer zone. （2） Kalium-magnesium deposits exist in semi-deep lake subphase, shallow lake subphase, lakeshore subphase and lake delta subphase, the former one has larger thickness. （3）The Vientiane Basin is asymmetric with its deeper east and shallower west, and its paleogeography characteristics is similar extremely to nowadays. （4）In the deposition prosess, basin basement deceased continuously until gradually it tended to be stable. Brine is desalinated rapidly from it concentrated gradually, paleoclimate gets dampheat and rainy from its early drying and hot, water changes from weak reduction to weak oxidation.
出处
《盐湖研究》
CSCD
2008年第2期1-6,共6页
Journal of Salt Lake Research
基金
国家发展计划委员会"老挝万象平原钾盐矿勘查"(计外资[1999]2298号)
关键词
老挝
万象平原
含钾地层
沉积岩相
古地理
Laos
Vientiane plain
Potassium-bearing strata
Sedimentary lithofacies paleogeography
