• 责任者：Wang Chunlian (Key Laboratory of Metallogeny and Mineral Assessment ; MLR ; Institute of Mineral Resources ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Liu Chenglin
• 刊名：Acta Geoscientica Sinica
• 出版年：2013
• 卷期：34(5)
• 关键词：盐湖 ; salt lakes ; 碳酸盐岩 ; carbonate rocks ; 江汉平原 ; Jianghan Plain
• 页码：p.567-576
• 图表：6 illus., 3 tables, 41 refs.
• 分类号：1002
• issnNo：ISSN1006-3021
• isbnNo：CN11-3474/P

     The Jiangling depression is located in the west of Jianghan rift basin, and potassium-rich brine was mainly formed in Palaeocene. The study of the palaeoclimate evolution in Palaeocene has great theoretical and practical significance for further potash survey. The δ13CPDB values of carbonate in Shashi Formation of Jiangling depression vary between –4.8‰ and –1.0‰ with an average of –3.4‰; the δ18OPDB values are between –5.6‰ and –0.6‰ with an average of –3.3‰; the δ13CPDB values of carbonate in Xingouzui Formation of Jiangling depression are in the range of –10.8‰ ~ –8.8‰ with an average of –9.3‰; the δ18OPDB values are between –10.2‰ and –6.7‰ with an average of –8.6‰. The δ13CPDB and δ18OPDB values of micrite in Shashi Formation show good positive correlation, suggesting a relative closed salt lake system with apparent evaporation. However, in Xingouzui Formation, the relationship between δ13CPDB and δ18OPDB is indistinct, implying an open lake system whose water was stagnant only for a short time. The carbon and oxygen isotopes as well as Sr/Ba and Mg/Ca ratios reveal that Shashi Formation had relatively high paleosalinity and evaporation/raining ratio. The paleo-lake surface is higher in Xingouzui Formation than in Shashi Formation. The differences of carbon and oxygen isotope compositions of the Palaeocene lake in Jiangling depression reveal the change from dry-hot climate in Shashi Formation to wet climate in Xingouzui Formation. It is thus inferred that the palaeoclimate changed greatly from Shashi Formation to Xingouzui Formation in Jiangling depression throughout the Paleogene period. This change was favorable for the salt lake evolution and potassium deposition in Shashi Formation.