The Impact of the Linked Factors of Provenance,Tectonics and Climate on Potash Formation:An Example from the Potash Deposits of Lop Nur Depression in Tarim Basin,Xinjiang,Western China

作     者：LIU Chenglin JIAO Pengcheng Lü Fenglin WANG Yongzhi SUN Xiaohong ZHANG Hua WANG Licheng YAO Fojun 

作者机构：MLR Key Laboratory of Metallogeny and Mineral AssessmentInstitute of Mineral ResourcesChinese Academy of Geological Sciences School of Earth Sciences and ResourcesChina University of Geosciences College of Instrumentation & Electrical EngineeringJilin University 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2015年第89卷第6期

页      面：2030-2048页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：funded by the National Basic Research Program of China(No.2011CB403007) the State Key Program of National Natural Science of China(No.40830420) 

主　　题：Potash formation coupling mechanism provenance tectonics climate Lop Nur Tarim basin 

摘      要：Potash deposits commonly accumulate in highly restricted settings at the final stage of brine evaporation. This does not mean that potash deposits are formed simply as a result of the evaporation concentration of seawater or lake water, but rather as a coupling result of particular provenance, tectonics and climate activities. In this paper, we focus on the formative mechanism of the potash deposits of Lop Nur depression in Tarim Basin to interpret the detailed coupling mechanism among provenance, tectonics and climate. In terms of the provenance of Lop Nur Lake, the water of the Tarim River which displays ＂potassium-rich＂ characteristics play an important role. In addition, the Pliocene and Lower-Middle Pleistocene clastic beds surrounding Lop Nur Lake host a certain amount of soluble potassium and thus serves as ＂source beds＂ for potash formation. During the late Pliocene, the Lop Nur region has declined and evolved into a great lake from the previous piedmont and diluvial fan area. Since the mid Pleistocene, the great-united Lop Nur Lake has been separated and has generated a chain system consisting of Taitema Lake, Big Ear Lake and Luobei Lake which has turned into the deepest sag in Lop Nur Lake. Dry climate in Lop Nur region has increased since the Pliocene, and became extreme at the late Pleistocene. The study implies that potash formation in Lop Nur Lake depends on the optimal combination of extreme components of provenance, tectonics and climate during a shorter-term period. The optimal patterns of three factors are generally characterized by the long-term accumulation and preliminary enrichment of potassium, the occurrence of the deepest sub-depression and the appearance of an extremely arid climate in Lop Nur region. These factors have been interacting synergistically since the forming of the saline lake and in the later stages strong ＂vapor extraction＂ caused by extremely arid climate is needed to trigger large scale mineralization of potash deposits.