首页|Mobility of rhenium and selenium during chemical weathering and their implication for petrogenic organic carbon oxidation

Mobility of rhenium and selenium during chemical weathering and their implication for petrogenic organic carbon oxidation

扫码查看
The oxidative weathering of petrogenic organic carbon(OCpetro)is an important source of carbon dioxide(CO2)into the atmosphere on geological timescales and significantly influences the carbon cycle and global climate change.However,at present,a robust proxy to assess OCpetro oxidation is lacking.Riverine rhenium(Re)has emerged as a potential proxy to trace OCpetro oxidation,but little is known about Re sources and its relationship with OCpetro oxidation.To better understand the robustness of this proxy,we analyzed a shale weathering profile from the early Cambrian Shuijingtuo Formation in Chengkou County,Chongqing City,to address the mobility of Re and selenium(Se)and their relationship with the oxidation of OCpetro by analyses of the elemental variation and sequential extraction.The results showed that the chemical index of alteration(CIA)increases from the fresh bedrock to the weathered sections,indicating enhanced weathering intensity.Based on the sequential extraction and mass transfer coefficients(r),Re and Se mainly exist in the organic phase of shale and are paired lost with OCpetro during weathering,with no obvious correlation with sulfide minerals.Furthermore,the different proportions of Re and Se loss with OCpetro loss can be attributed to their different geochemical behaviors during weathering.Our study supports Re as a robust proxy to trace OCpetro oxidation,whereas Se is the potential one.In the future,combined studies on various sedimentary rock profiles with catchment basins are needed to determine the sources of riverine Re and Se and their relationships with OCpetro oxidation.

Rhenium and seleniumShaleMobilityOCpetroChemical weathering

Yuhong ZHANG、Jin WANG、Yuanxin QU、Chao ZHU、Zhangdong JIN

展开 >

State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi'an 710061,China

University of Chinese Academy of Sciences,Beijing 100049,China

Xi'an Institute for Innovative Earth Environment Research,Xi'an 710061,China

Institute of Global Environmental Change,Xi'an Jiaotong University,Xi'an 710049,China

展开 >

国家重点研发计划国家自然科学基金

2022YFF080050041991322

2024

中国科学:地球科学(英文版)
中国科学院

中国科学:地球科学(英文版)

影响因子:1.002
ISSN:1674-7313
年,卷(期):2024.67(3)
  • 66