中国湖相碳酸盐岩碳氧同位素时空特征及其古湖泊学意义  

Temporal and spatial characteristics of C-O isotopes of Lacustrine carbonate in China and the Paleolimnological significance

作　　者：梁俊红[1] 孙宝亮[1] 尹国英[2] LIANG Junhong;SUN Baoliang;YIN Guoying(Geology Department of school of Resources and civil Engineering of The Northeast University,Shenyang 110819,China;Structural Engineering department of Liaoning Urban Construction Technical College,Shenyang 110122,China)

机构地区：[1]东北大学资源与土木工程学院地质系,沈阳110819 [2]辽宁城市建设职业技术学院建筑工程系,沈阳110122

出　　处：《地质找矿论丛》2022年第4期369-383,共15页Contributions to Geology and Mineral Resources Research

基　　金：中央高校基本科研业务费项目(编号:N100401005)资助。

摘　　要：湖相碳酸盐岩是一种分布极其广泛的陆相碳酸盐岩。中国湖相碳酸盐岩沉积始于二叠纪—三叠纪,经侏罗纪—白垩纪发展,鼎盛于古近纪,具有沉积时间跨度长、分布面积广的特征。碳酸盐岩发育方式多样,常以多个单层、薄夹层状、互层状、韵律沉积为主,也见以结核状或钙质微体化石等薄层赋存于泥岩、页岩等细粒碎屑岩中。湖相碳酸盐岩δ^(13)C值介于-10.0×10^(-3)~+10.0×10^(-3)之间,多数为-5.0×10^(-3)~+5.0×10^(-3),正负值均有。二叠系—三叠系δ^(13)C发生负偏,侏罗系—白垩系先正向漂移随后负偏,古近系—新近系再次正偏,达最大值约+5.0×10^(-3)。氧同位素δ^(18)O值介于-20.0×10^(-3)~+2.0×10^(-3)之间,多数为-15.0×10^(-3)~-0.0×10^(-3),几乎全部为负值。二叠系—三叠系、侏罗系—白垩系碳酸盐岩δ^(18)O值在-15.0×10^(-3)~-3.0×10^(-3)之间变化,古近系—新近系δ^(18)O值明显正偏移,多数位于-10.0×10^(-3)~0.0×10^(-3)。中国湖相碳酸盐岩碳氧同位素相关性分析表明,δ^(13)C与δ^(18)O密切相关,且δ^(13)C值多正值或轻微负值,指示湖泊为封闭型咸水—半咸水环境;δ^(13)C和δ^(18)O不相关,δ^(13)C值为负值,指示湖泊为开放型淡水环境。Lacustrine carbonate rock is a widely distributed continental facies.In China it is also widely distributed and precipitated in long terms beginning in Permian-Triassic period,developing in Jurassict-Cretaceous period and flourishing in Paleogene.It occurs in different forms,such as the dominant rhythmic multi-single layers,thin intercalith and interbeded layers,thin nodular and calcareous micro-fossil layers in mudstone or shale.The value is in range -10.0×10^(-3)~+10.0×10^(-3) and most of the value in range -5.0×10^(-3)~+5.0×10^(-3) in Permian-Triassic period tends to be negative,in Jurassic-Cretaceous period first to be positive and then negative,in Paleogene to be positive with top value +5.0×10^(-3).The value is in range -20.0×10^(-3)~+2.0×10^(-3) and most of the value in range -15.0×10^(-3)~0.0×10^(-3) of which almost are negative.The value of Permian-Triassic period and Jurassic-Cretaceous period is in range -15.0×10^(-3)~-3.0×10^(-3),the value of Paleogene -10.0×10^(-3)~0.0×10^(-3) tend to be positive.Analysis of correlation of C and O isotopes shows that and are closely correlated and most positive,slightly negative indicating that the lakes is under closed environment with saline-semisaline water,are not correlated and value negative indicating that the lakes under open environment with fresh water.

关 键 词：湖相碳酸盐岩 岩石学 碳氧同位素 古湖泊学 

分 类 号：P588.245[天文地球—岩石学] P597.2[天文地球—地质学]