• 责任者：Liu Chenglin (Key Laboratory of Metallogeny and Mineral Assessment ; MLR ; Institute of Mineral Resources ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Cao Yangtong
• 刊名：Acta Geoscientica Sinica
• 出版年：2013
• 卷期：34(5)
• 关键词：盐湖 ; salt lakes ; 钾盐矿床 ; potash deposit ; 库车坳陷 ; Kuqa Depression
• 页码：p.547-558
• 图表：9 illus., 1 table, 36 refs.
• 分类号：1002
• issnNo：ISSN1006-3021
• isbnNo：CN11-3474/P

     Evaporites with large thickness were formed in Kuqa foreland basin during Paleogene-Neogene period.The paleo-salt lake deposits during Paleocene were mainly distributed in central and estern Baicheng depression in the west of Kuqa Basin; then the paleo-salt lake deposits expanded into almost entire Baichengdepression and both depocenter and brine enrichment center of salt lake located in the north part during Eocene; after that the salt lake deposits were still distributed in the most of the depression during Oligocene, but evaporites and brine enrichment center had already moved to its south, and hence the previous tectonic pattern of the half-graben basin characterized by ＂deep in the north and shallow in the south＂ was remarkably altered; finally, with the migration of the depocenter from Baicheng depression to Yangxia depression in the east of the basin during Miocene, the salt lake sediments also moved eastward. The brine enrichment centers occured as bead distribution during Paleocene to Miocene. The evolution of paleogeography of Kuqa basin indicated that the development and migration of sub-depression was strongly influenced by tectonic activities in the baisn, which controled the paleogeography of salt lake （e.g, depocenter, material source and brine enrichment center） and might have played an important role in the later potential formation of potash deposits. Further analysis reveals that enrichment tendency for potassium in evaporite sequence also controlled obviously by the paleogeographic changes of the Basin, namely, potassium enrichments should have occurred in the regions with large area and great thickness of the salt deposits. The fact that, potassium content of salt rock cuttings in some oil drill holes gradually  increased from the bottom to the top, for example, in the western Baicheng depression, the maximum values of  potassium content are 1.07%, 1.43%, 3.05% upward in one drill hole, and in the eastern Yangxia depression, the  potassium content varies from 0.008% to 0.152%, was just the geochemical response to the enrichment trend of  potassium content controlled by change of lithofacies and paleogeography in the paleo-salt lake. From the above, it  can predict that the Kuqa foreland basin has good potash metallogenic prospects, which might exist in brine  enrichment center of Baicheng depression in Eocene time and probably migrate to the center of Yangxia depression  in Miocene time.