Volume 35, Issue 8 e14330
RESEARCH ARTICLE

Chemical weathering and CO2 consumption in the glaciated Karuxung River catchment, Tibetan Plateau

Fan Zhang

Fan Zhang

State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

University of Chinese Academy of Sciences, Beijing, China

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Xiong Xiao

Corresponding Author

Xiong Xiao

College of Geographic Science, Hunan Normal University, Changsha, China

Correspondence

Xiong Xiao, College of Geographic Science, Hunan Normal University, Changsha, China.

Email: [email protected]

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Lijie Wang

Lijie Wang

State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

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Chen Zeng

Chen Zeng

State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

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Zhengliang Yu

Zhengliang Yu

State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

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Guanxing Wang

Guanxing Wang

State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

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Xiaonan Shi

Xiaonan Shi

State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China

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First published: 01 August 2021
Citations: 6
Funding information National Natural Science Foundation of China, Grant/Award Numbers: 41771090, 41988101-03, 41422101

Abstract

Climate factors play critical roles in controlling chemical weathering, while chemically weathered surface material can regulate climate change. To estimate global chemical weathering fluxes and CO2 balance, it is important to identify the characteristics and driving factors of chemical weathering and CO2 consumption on the Tibetan Plateau, especially in glaciated catchments. The analysis of the hydro-geochemical data indicated that silicate weathering in this area was inhibited by low temperatures, while carbonate weathering was promoted by the abundant clastic rocks with fresh surfaces produced by glacial action. Carbonate weathering dominated the riverine solute generation (with a contribution of 58%, 51%, and 43% at the QiangYong Glacier (QYG), the WengGuo Hydrological Station (WGHS), and the lake estuary (LE), respectively). The oxidation of pyrite contributed to 35%, 42%, and 30% of the riverine solutes, while silicate weathering contributed to 5%, 6%, and 26% of the riverine solutes at the QYG, WGHS, and LE, respectively. The alluvial deposit of easily weathering fine silicate minerals, the higher air temperature, plant density, and soil thickness at the downstream LE in comparison to upstream and midstream may lead to longer contact time between pore water and mineral materials, thus enhancing the silicate weathering. Because of the involvement of sulfuric acid produced by the oxidation of pyrite, carbonate weathering in the upstream and midstream did not consume atmospheric CO2, resulting in the high rate of carbonate weathering (73.9 and 75.6 t km−2 yr−1, respectively, in maximum) and potential net release of CO2 (with an upper constraint of 35.6 and 35.2 t km−2 yr−1, respectively) at the QYG and WGHS. The above results indicate the potential of the glaciated area of the Tibetan Plateau with pyrite deposits being a substantial natural carbon source, which deserves further investigation.

CONFLICT OF INTEREST

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request. Moreover, all the water chemistry data used in this paper are shown in Table A1 in the Appendix.

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