地质学报2017，Vol.91Issue(3)：605-616,12.
吉木萨尔凹陷芦草沟组碳酸盐岩碳氧同位素特征及其古湖泊学意义
Carbon and Oxygen Isotope Compositions of Carbonatic Rock from Permian Lucaogou Formation in the Jimsar Sag,NW China and Their Paleolimnological Significance
摘要
Abstract
The Lucaogou Formation in the Jimsar sag is the important lacustrine tight oil-bearing accumulation in the Junggar basin.In order to understand the environmental characteristics of the paleolimnological deposition,experiments were carried out by means of phosphoric acid method on the Lucaogou Formation carbonate in the Jimsar sag.Results indicate that δ13C values of carbonatic rocks range from 6.8‰ to 9.7‰ with an average of 8.3‰,and δ18O from-11.9‰ to-4.3‰ with an average of-6.2‰.Characters and variation of δ18O and δ13 CPDB indicate that paleolakes were characterized by open lake with short periodic fresh water injection during early stage and by highly saline lakes with long hydraulic residence time and high confine during late stage.Massive nourishment carried by volcanic materials gave rise to prosperous growth of organisms,resulting in high δ13C in lacustrine carbonatic rock,and cyclic input of precipitation bearing light oxygen isotope distinctly decreased δ18O in lacustrine carbonatic rock.During sedimentation of the Lucaogou Formation,the paleolake was featured by high salinity with frequent variation.Influenced by cyclic precipitation and intensive evaporation,water level of paleolake varied from high to low to high or from high to low,and correspondingly,the salinity also varied from low to high to low or from low to high.关键词
吉木萨尔凹陷/芦草沟组/碳酸盐岩/碳氧同位素/古沉积环境Key words
Jimsar sag/Lucaogou Formation/carbonates/carbon and oxygen isotopes/palaeoenvironment引用本文复制引用
曲长胜,邱隆伟,杨勇强,陈程,汤丽莉,余宽宏,万敏..吉木萨尔凹陷芦草沟组碳酸盐岩碳氧同位素特征及其古湖泊学意义[J].地质学报,2017,91(3):605-616,12.基金项目
本文为国家重点基础研究发展计划“973”项目(编号2014CB239002),山东省自然科学基金青年基金项目(编号ZR2014DQ016)和中国石油大学(华东)研究生创新工程项目(编号YCXJ2016010)资助成果. （编号2014CB239002）
