Although the distribution of mono-,di-and trimethylated 2-methyl-2-(4,8,12-Trimethyltrideeyl) chromans(MTTCs) is well understood as an indicator of water salinity,their origin and formation mechanism are still ambiguo...Although the distribution of mono-,di-and trimethylated 2-methyl-2-(4,8,12-Trimethyltrideeyl) chromans(MTTCs) is well understood as an indicator of water salinity,their origin and formation mechanism are still ambiguous and under debate.In this paper,abnormally high levels of MTTCs were detected in Cenozoic saline lacustrine source rocks from the Western Qaidam Basin.Using a two-step column chromatography method,the MTTCs and naphthalenes were separated from other aromatic compounds and concentrated in one fraction,so that the stable carbon isotope compositions of these compounds could be accurately measured.Similar carbon isotope ratios for the mono-,di-and trimethylated 2-methyl-2-(4,8,12-Trimethyltrideeyl) chromans in a given sample suggest the MTTCs may share the same biological source(s).The MTTCs from the Western Qaidam Basin have similar carbon isotope compositions to primary producer-derived pristane and phytane.However,the ? 13C values for the MTTCs showed significant differences with other primary producers-derived biomarkers(e.g.C27 and C29 steranes),probably indicating a distinct microalgae source from specific niches for the MTTC compounds.We speculate that the MTTCs distribution patterns may be controlled by the water chemistry dynamics in niches,which,in turn,is affected by hypersaline bottom water.展开更多
二氧化碳捕集与封存(CO2 capture and storage,CCS)是全球CO2减排最重要技术战略,但CCS相关项目存在CO2泄漏的风险不容忽视,及时有效的识别与监测项目区CO2泄漏至关重要。文中以7种典型C3、C4植物为研究对象,通过模拟地质封存CO2泄漏产...二氧化碳捕集与封存(CO2 capture and storage,CCS)是全球CO2减排最重要技术战略,但CCS相关项目存在CO2泄漏的风险不容忽视,及时有效的识别与监测项目区CO2泄漏至关重要。文中以7种典型C3、C4植物为研究对象,通过模拟地质封存CO2泄漏产生的超高CO2浓度对植物稳定碳同位素组成δ13C的影响,分析C3、C4植物δ13C值与超高CO2浓度之间的关系,试图利用植物δ13C分析识别CO2泄漏。结果表明:C3、C4植物的δ13C值能够迅速响应CO2浓度的变化,均呈现随着CO2浓度的增加而先迅速下降后缓慢稳定的态势,其中C3、C4植物δ13C值分别在CO2浓度为10000μmol·mol-1、20000μmol·mol-1时降低显著,C3植物的δ13C值从-28.9‰变化到-47.0‰,C4植物的δ13C值从-15.1‰变化到-43.8‰,C4植物在超高CO2浓度下的δ13C变化远大于C3植物,且与CO2浓度有较强相关性(R2≥0.6343);当二氧化碳浓度大于20000μmol·mol-1时C4植物δ13C值与正常大气环境C4植物δ13C值差异显著,利用C4植物δ13C可有效识别CO2的泄漏。展开更多
基金supported by the National Natural Science Foundation of China (40972093)the National Special Program of Oil and Gas in China (2011ZX05008-002)+1 种基金the Natural Science Foundation of Zhejiang Province (R5080124)the Fundamental Research Funds for the Central Universities
文摘Although the distribution of mono-,di-and trimethylated 2-methyl-2-(4,8,12-Trimethyltrideeyl) chromans(MTTCs) is well understood as an indicator of water salinity,their origin and formation mechanism are still ambiguous and under debate.In this paper,abnormally high levels of MTTCs were detected in Cenozoic saline lacustrine source rocks from the Western Qaidam Basin.Using a two-step column chromatography method,the MTTCs and naphthalenes were separated from other aromatic compounds and concentrated in one fraction,so that the stable carbon isotope compositions of these compounds could be accurately measured.Similar carbon isotope ratios for the mono-,di-and trimethylated 2-methyl-2-(4,8,12-Trimethyltrideeyl) chromans in a given sample suggest the MTTCs may share the same biological source(s).The MTTCs from the Western Qaidam Basin have similar carbon isotope compositions to primary producer-derived pristane and phytane.However,the ? 13C values for the MTTCs showed significant differences with other primary producers-derived biomarkers(e.g.C27 and C29 steranes),probably indicating a distinct microalgae source from specific niches for the MTTC compounds.We speculate that the MTTCs distribution patterns may be controlled by the water chemistry dynamics in niches,which,in turn,is affected by hypersaline bottom water.
文摘二氧化碳捕集与封存(CO2 capture and storage,CCS)是全球CO2减排最重要技术战略,但CCS相关项目存在CO2泄漏的风险不容忽视,及时有效的识别与监测项目区CO2泄漏至关重要。文中以7种典型C3、C4植物为研究对象,通过模拟地质封存CO2泄漏产生的超高CO2浓度对植物稳定碳同位素组成δ13C的影响,分析C3、C4植物δ13C值与超高CO2浓度之间的关系,试图利用植物δ13C分析识别CO2泄漏。结果表明:C3、C4植物的δ13C值能够迅速响应CO2浓度的变化,均呈现随着CO2浓度的增加而先迅速下降后缓慢稳定的态势,其中C3、C4植物δ13C值分别在CO2浓度为10000μmol·mol-1、20000μmol·mol-1时降低显著,C3植物的δ13C值从-28.9‰变化到-47.0‰,C4植物的δ13C值从-15.1‰变化到-43.8‰,C4植物在超高CO2浓度下的δ13C变化远大于C3植物,且与CO2浓度有较强相关性(R2≥0.6343);当二氧化碳浓度大于20000μmol·mol-1时C4植物δ13C值与正常大气环境C4植物δ13C值差异显著,利用C4植物δ13C可有效识别CO2的泄漏。
