| 摘要: |
| 为在我国新生代大陆沉积盆地开展区域找矿及钾盐资源预测提供科学依据,采用地球卫星遥感资料和地面调查与化学测试以及区域盐湖卤水演化环境的演绎分析等手段,综合方法,揭示了罗布泊盆地第四纪沉积层序和湖泊气候环境变化的基本特征与古湖泊湖水及现代湖水的饱和流结晶路线及成盐成矿演化趋势。区域盐湖卤水演化环境和地质钻探资料及相图表明,罗布泊地区钾盐矿床的成盐矿物以钾的硫酸盐矿物为主,并没有出现真正意义上的钾盐沉积阶段(即氯化物钾盐析出阶段),而钾盐卤水矿床却是一个积极的找矿方向。根据断裂组合及深部地质作用的分析,这一地段是现代地质作用条件下形成的呈北东向展布的地堑构造系统,富钾卤水蕴藏在地堑构造系统的中央断裂带内。
综合分析表明,通过地堑构造系统的中央断裂的贯通作用,使深层卤水以及表层渗滤水向断裂破碎部位聚集,并由于深部卤水的运动,使深层盐岩系地层发生选择性溶解和表层渗滤水,使浅部疏松堆积物的易溶性氧化钾溶解,从而导致富钾卤水的富集而形成超大型液体钾盐矿床。 |
| 关键词: 罗布泊 液体钾盐矿床 卤水 古气候 古湖泊地层学 地堑 第四纪 |
| DOI： |
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| 基金项目:国家可可西里地区综合科学考察基金项目,D000204号;西北大学大陆动力学国家重点实验室开放基金项目,DL200601号;淮海工学院科学基金项目,20040826号联合资助 |
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| THE QUATERNARY SEDIMENTARY SEQUENCE AND POTASSIUM DEPOSIT IN THE LUOBU LAKE, CHINA |
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HU Dong-Sheng1,2,3, ZHANG Hua-Jing4, XU Bing5, TIAN Xin-Hong2, CHEN Li-Xin1, PENG Bo1, ZHANG Guo-Wei2
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1.College of Resource and Environmental Sciences, Hunan Normal University, Changsha, 410081;2.State Key Laboratory of Continental Dynamics, Northwest University,Xi’an,710069;3.Department of Space Information Sciences, Huaihai Engineering College, Lianyungang, 222001;4.College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081;5.College of Marine Geosciences, Ocean University of China,Qingdao, 266071
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| Abstract: |
| Luobu Lake (i.e. Luobupo or Lop Nur), is a well-known mysteries place for adventure in Xinjiang, Northwest China, centered at about 39° - 41° N/88° - 92° E near northeastern tip of the Tarim Basin. It was a populated place several thousand years ago and now is under desertification with rich underground brine resource. The authors used the data of satellite remote sensing, geological field survey, and chemical measurement of this area to study regional salt lake brine and its revolution. The study established the Quaternary sequential stratigraphy that helps understand the paleo-geography and paleo-climate of this area. Moreover, the mechanism of transfer/transformation of saturated lake water flow to crystallized salts from ancient to present lakes was studied, which helps explore potential potassium resource. Regional geology survey and drilling show that the potassium deposits in the area are made of mainly potassic sulphates, and actually no direct potassic sedimentation from chloride potassium was found in the region. Exploration should be focused on rich underground potassic brine. The brines distribute in central section of a NE- directed graben system formed by neo-tectonic movements. Analysis shows that the central faulting system in the graben has cut through deeply-seated brines and connected with surface osmosis water along fracture zones. The movement of deep-seated brine caused selective dissolution in deep brine system, and the surface osmotic water dissolved easily dissolvable potassium oxide in shallow loose materials. Consequently, this process formed rich and supper-large underground liquid potassium salt deposits in the study area. |
| Key words: Luobu Lake (Lobupo, Lop Nur), Liquid potassium deposit, Brine, Paleo-climate, Paleo-lacustrine stratigraphy, Quaternary |
