Soluble salt deposit in the Nihewan beds and its environmental significance  

作　　者：李容全 乔建国 邱维理 翟秋敏 李永良 

机构地区：[1]Department of Resources and Environmental Science, Beijing Normal University, Beijing 100875, China [2]Dean's Office of Shanxi Normal University, Linfen 041004, China [3]The Center for Analyses and Tests, Beijing Normal University, Beijing 100875, China

出　　处：《Science China Earth Sciences》2000年第5期464-479,共16页中国科学（地球科学英文版）

摘　　要：Observation and experimental analysis of soluble salt deposit along four profiles across the strata deposited in Nihewan paleolake basin enabled us to recognize the nature and evolution stages of the Nihewan paleolake and its significance in stratigraphical division and pa-leo-environmental reconstruction. The Nihewan paleolake was at least a weak-saline to semi-saline lake and represents an intracontinental lake in the semi-arid region. The lower member of sedimentary strata in the paleolake contains gypsum layer and gypsum lamellae. Soluble salt is mainly composed of SO42- and Ca2+ ions, representing a trend of the paleolake evolvinginto a stage of sulfate lake. The upper member of the strata has predominantly Cl-, K+, and Na+ ions in soluble salt, indicating a starting development of the paleolake to chlorite lake, but no salt rock was deposited, indicating a drying trend of the area.Observation and experimental analysis of soluble salt deposit along four profiles across the strata deposited in Nihewan paleolake basin enabled us to recognize the nature and evolution stages of the Nihewan paleolake and its significance in stratigraphical division and pa-leo-environmental reconstruction. The Nihewan paleolake was at least a weak-saline to semi-saline lake and represents an intracontinental lake in the semi-arid region. The lower member of sedimentary strata in the paleolake contains gypsum layer and gypsum lamellae. Soluble salt is mainly composed of SO 4 2- and Ca2+ ions, representing a trend of the paleolake evolving into a stage of sulfate lake. The upper member of the strata has predominantly Cl-, K+, and Na+ ions in soluble salt, indicating a starting development of the paleolake to chlorite lake, but no salt rock was deposited, indicating a drying trend of the area.

关 键 词：Nihewan BEDS SOLUBLE salt DEPOSIT PALEO-ENVIRONMENT semi-saline lake. 

分 类 号：P512.2[天文地球—地质学]