Liu Wenjing, Xu Zhifang, Sun Huiguo, Zhao Mingyu, Xu Yifu, Guo Zhengtang
State Key Laboratory of Lithospheric and Environmental Coevolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China.
College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China.
Nat Commun. 2025 Mar 20;16(1):2741. doi: 10.1038/s41467-025-58046-4.
Estimation of net CO consumption by weathering in orogen is complicated as high erosion rate promotes competing processes of CO consumption (silicate weathering) and releasing (sulfuric acid (HSO) dissolution of carbonate). Quantification of HSO disturbing on weathering is missing in the Tibetan Plateau, hindering the understanding of Himalayan orogenesis impact on global carbon cycle. Here we calculate the riverine solute contributions from both carbonic and sulfuric acid mediated weathering, and their weathering fluxes with major river geochemistry dataset from the Tibetan Plateau. We find that silicate weathering is not anomalous, while carbonate weathering flux is 2.09% of the global value with 1.01% drainage area. Over 80% HSO originated from pyrite oxidation is consumed by carbonate weathering, which counteracts ~58% of the CO consumption flux by silicate weathering. The refined weathering CO budget in this work provides quantitative modern evidence for pyrite weathering in orogen serving as negative feedback on atmospheric pCO.
造山带中通过风化作用对净二氧化碳消耗的估算很复杂，因为高侵蚀率促进了二氧化碳消耗（硅酸盐风化）和释放（碳酸盐的硫酸（H₂SO₄）溶解）这两个相互竞争的过程。青藏高原缺少对风化作用中硫酸干扰的量化，这阻碍了对喜马拉雅造山运动对全球碳循环影响的理解。在此，我们利用青藏高原主要河流地球化学数据集，计算了碳酸和硫酸介导的风化作用对河流溶质的贡献及其风化通量。我们发现硅酸盐风化并无异常，而碳酸盐风化通量占全球值的2.09%，流域面积占全球的1.01%。超过80%源自黄铁矿氧化的硫酸被碳酸盐风化作用消耗，这抵消了约58%的硅酸盐风化作用对二氧化碳的消耗通量。这项工作中细化的风化作用二氧化碳收支为造山带中黄铁矿风化作为对大气pCO₂的负反馈提供了定量的现代证据。
