刚果盆地西南部白垩纪蒸发岩矿物与古环境特征  

Mineral deposition and paleoenvironment of Cretaceous evaporite in Southwestern Congo

作　　者：颜开 刘成林[1] 王春连[1] 范美玲 徐海明[1] 王九一 YAN Kai;LIU Cheng-lin;WANG Chun-lian;FAN Mei-ling;XU Hai-ming;WANG Jiu-yi(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;State Key laboratory of Geological Processes and Mineral Resources,School of the Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China)

机构地区：[1]中国地质科学院矿产资源研究所,自然资源部成矿作用与资源评价重点实验室,北京100037 [2]中国地质大学地球科学与资源学院,地质过程与矿产资源国家重点实验室,北京100083

出　　处：《岩石矿物学杂志》2021年第3期525-534,共10页Acta Petrologica et Mineralogica

基　　金：中央级公益性科研院所基本科研业务费专项(KK2005,KK2016);国家"973计划"项目(2011CB403007);中国地质调查局地质矿产调查评价专项项目(DD20190437,DD20190606)。

摘　　要：刚果(布)西南部布谷马西地区属于热带雨林气候,拥有非洲大陆西部边缘重要的白垩纪钾盐矿床,属于典型的裂谷成钾盆地。经矿物学研究表明,主要的蒸发岩矿物类型为石盐、光卤石、钾石盐、水氯镁石、溢晶石、石膏、硬石膏等。蒸发岩矿物沉积序列为石膏、硬石膏(多数旋回缺失)→石盐→光卤石→钾石盐(次生)→溢晶石或水氯镁石。通过蒸发岩矿物沉积特征和微量元素的分析认为,在白垩纪时期布谷马西地区处于长期的高温干旱环境,有利于卤水蒸发、浓缩而形成盐类矿物沉积。The Mboukoumassi region of Congo has tropical rain forest climate,possesses important Cretaceous potash deposits at the western edge of the African continent,and hence belongs to the typical rift potassium basin.Mineralogical studies show that the main types of evaporite minerals are chloride minerals comprising halite,carnallite,kalitite,brucite and spillite,sulfate minerals comprising gypsum,anhydrite and some other minerals.The sequence of evaporite mineral deposition is in order of gypsum,anhydrite(most cycles are missing)→stone salt→carnallite→potassium salt(secondary)→spillstone or magnesite.According to the characteristics of evaporite mineral deposition and the analysis of trace elements,it is shown that,in the Cretaceous period,the Mboukoumassi area was in a long-term high temperature and dry environment,which was conducive to the evaporation and concentration of brine and the formation of salt mineral deposition.

关 键 词：布谷马西地区 蒸发岩矿物 沉积序列 高温干旱 

分 类 号：P588.247[天文地球—岩石学]