摘要
表生钾盐成矿是地球系统多圈层相互作用的结果。我国现有钾盐矿大多集中在青藏高原周缘,时代为中-新生代,然而钾盐矿床聚集和保存机制仍然不清,制约了钾盐找矿的突破。本文综述了近年来高原周缘各盆地钾盐成矿研究的若干进展。思茅-呵叻钾盐成矿带成矿时代为中-晚白垩世,但盆地间含钾序列对比困难;成钾卤水与海水相关,但其源-汇系统在陆相环境中受到了构造地貌-气候的共同作用;提出干旱背景下风成砂岩-钾盐指状交叉叠置的模式。四川盆地嘉陵江组四段第二亚段是固体钾盐的有利时期,嘉陵江组五段第二亚段至雷口坡组一段第一亚段以及雷口坡组四段第二亚段是富钾卤水的有利聚集期;但固体钾盐和富钾卤水的成因和模式仍待进一步研究。察尔汗盐湖成钾作用具有在晚更新世以来短时爆发的特点,地表河水可能是重要的补给来源,构造作用在含盐盆地迁移和深部卤水富集中具有明显的控制作用。本文提出构造-古地理作用是制约海/陆相钾盐成矿和保存的核心因素,控制了含蒸发岩盆地古气候、海水成分变化和盆地封闭条件,以及成钾期后改造、变形和保存。本文提出今后的研究要注重地球系统科学思维,要以构造-古地理为主线,创新出适合各盆地自身地质规律的成钾模式;未来的找钾突破重点是明确成钾后期构造改造和保存的问题。本文还提出了塔里木、四川和思茅盆地等今后重点研究和勘查的方向。
The formation of supergene potash deposits is a result of multi-layer interaction of the Earth system.Most existing potash deposits in China are concentrated around the Tibetan Plateau and its adjacent area with Mesozoic-Cenozoic ages.However,the mechanisms responsible for the accumulation and preservation of potash deposits remain unclear,hindering breakthroughs in potash exploration.This paper reviews recent advancements in the study of potash mineralization in various basins along the periphery of the Tibetan Plateau.The Simao-Khorat potash metallogenic belt was formed during the Middle to Late Cretaceous;however,correlating potash-bearing sequences between basins remains challenging.Potash brines are sourced from seawater,but their source-sink systems in continental environments are influenced by tectonic,geomorphological and climatic factors.A model of aeolian sandstone-potash salt sigmoidal cross-stratification is proposed under arid conditions.In the Sichuan Basin,the second submember of the fourth member of the Jialingjiang Formation is a favorable period for solid potash salt formation.The second submember of the fifth member of the Jialingjiang Formation to the first submember of the first member of the Leikoupo Formation,as well as the second submember of the fourth member of the Leikoupo Formation,are favorable periods for the accumulation of potash-rich brines.However,the genesis and models of solid potash salts and potash-rich brines require further research.The potash mineralization in the Qarhan Salt Lake is characterized by short-term bursts since the Late Pleistocene.Surface river water may be an important recharge source,and tectonic activity has a significant controlling effect on the migration of salt basins and the concentration of deep brines.We propose that tectonic and paleogeographic factors are core scientific questions constraining the marine/continental potash mineralization and preservation,controlling the paleoclimate,seawater composition changes,and basin closure conditions of evaporite-bearing basins,as well as post-potash formation alteration,deformation,and preservation.Future research should focus on Earth system science thinking,with tectonic-paleogeography as the main line,innovating potash formation models suitable for the geological regularities of every single basin.The key to future potash exploration breakthroughs is to clarify the issues of post-potash formation tectonic alteration and preservation.This paper proposes future research and exploration directions in the Tarim,Sichuan,and Simao basins.
作者
王立成
吴驰华
张华
龚大兴
WANG LiCheng;WU ChiHua;ZHANG Hua;GONG DaXing(State Key Laboratory of Tibetan Plateau Earth System,Environment and Resources,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China;MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;Institute of Multipurpose Utilization of Mineral Resources,China Academy of Geological Sciences,Chengdu 610041,China)
出处
《岩石学报》
2025年第3期1014-1042,共29页
Acta Petrologica Sinica
基金
第二次青藏综合科学考察研究(2019QZKK0805)
国家自然科学基金项目(42172083、41872099、42230310)联合资助.
关键词
钾盐
构造作用
古气候
盐构造
成矿机制
青藏高原
Potash
Tectonics
Paleoclimate
Halokinesis
Metallogenic mechanism
Tibetan Plateau
