Estimation of carbon sinks in chemical weathering in a humid subtropical mountainous basin  

作　　者：TAO Zhen GAO QuanZhou WANG ZhenGang ZHANG ShengHua XIE ChenJi LIN PeiSong RUAN XiaoBing LI ShuHong MAO HaiRuo 

机构地区：[1]School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China [2]Guangdong Provincial Key Laboratory of Mineral Resource ＆ Geological Processes, Sun Yat-sen University, Guangzhou 510275, China [3]Department of Earth and Environmental Science, K.U. Leuven, Celestijnenlaan 200E, 3001 Heverlee, Belgium

出　　处：《Chinese Science Bulletin》2011年第35期3774-3782,共9页

基　　金：supported by the National Natural Science Foundation of China (40871143, 41071054 and 40671027);an Open Fund of the China Institute of Water Resources and Hydropower Research;the Guangdong Natural Science Foundation (7003669)

摘　　要：The fluvial geochemistry of the mainstream and tributaries of the Zengjiang River was investigated,and the mass balance approach and deduction methods were used to estimate the uptake of atmospheric CO2 through rock chemical weathering.The results showed that the chemical runoff mainly consisted of HCO3-,Ca2+,Na+,and dissolved Si,and that silicate mineral weathering was significant,but carbonate mineral weathering was a minor source of dissolved loads in the Zengjiang River basin because of the low amount of interlayered carbonate rock strata in the catchment.The ion composition indicated that atmospheric CO2 was the primary erosive agent for rock chemical weathering in the Zengjiang River basin.The CO2 consumption fluxes caused by rock chemical weathering were(3.50-3.81) × 105 mol km-2 a-1,which is just lower than that in tropical and subtropical basalt and carbonate regions,and is much higher than that in temperate and cold-temperate regions,indicating that surficial chemical weathering processes in the humid and hot monsoon current influencing the low-middle latitude zone of the Northern Hemisphere constitutes a significant carbon sink in the global biogeochemical cycle.The fluvial geochemistry of the mainstream and tributaries of the Zengjiang River was investigated, and the mass balance approach and deduction methods were used to estimate the uptake suits showed that the chemical runoff mainly consisted of HCO3 of atmospheric CO2 through rock chemical weathering. The resuits showed that the chemical runoff mainly consisted of HCO3^-, Ca^2＋, Na^＋, and dissolved Si, and that silicate mineral weathering was significant, but carbonate mineral weathering was a minor source of dissolved loads in the Zengjiang River basin because of the low amount of interlayered carbonate rock strata in the catchment. The ion composition indicated that atmospheric CO2 was the primary erosive agent for rock chemical weathering in the Zengjiang River basin. The CO2 consumption fluxes caused by rock chemical weathering were （3.50-3.81） ×10^5 mol km^-2 a^-1, which is just lower than that in tropical and subtropical basalt and carbonate regions, and is much higher than that in temperate and cold-temperate regions, indicating that surficial chemical weathering processes in the humid and hot monsoon current influencing the low-middle latitude zone of the Northern Hemisphere constitutes a significant carbon sink in the global biogeochemical cycle.

关 键 词：亚热带山地 化学风化 二氧化碳 生物地球化学循环 估算 盆地 潮湿 地球化学调查 

分 类 号：P512.1[天文地球—地质学]