中国科学院地理科学与资源研究所朱秉启等人，对玛纳斯河盆地的化学风化的驱动因素进行了研究。相关论文于2024年10月30日发表在《地球化学学报》杂志上。

大气和土壤中的CO₂在水中溶解产生的碳酸，通常是化学风化最主要的催化剂，但在以硅酸盐基岩为主的造山带流域，发现了一种不同于通常的硫酸驱动现象。

本研究立足于天山以北玛纳斯河盆地（MRB）的综合野外考察，深入探讨了硫酸和碳酸作为催化剂驱动中亚造山带，不同类型化学风化作用的机制和影响。定量分析表明，碳酸盐岩风化占化学风化总量的52.4%，硅酸盐和蒸发岩风化分别占18.6%和25.3%，人为活动和大气降水对化学风化的影响较小。

研究人员估计，MRB的总化学风化速率约为0.075 ×10⁶mol/km²/year。定量结果进一步表明，在碳酸盐沉淀前(<10⁴年)，化学风化可以吸收二氧化碳。随后，在碳酸盐沉淀（10⁴-10⁷年）之后，它将释放二氧化碳。这一排放量大大超过了全球平均二氧化碳消耗量，对气候造成了显著影响。

本研究强调了独特的风化机制，其中硫酸作为主要催化剂出现。作为催化剂的硫酸的用量大约是碳酸的三倍。硫酸驱动的碳酸盐岩风化（SCW）是唯一具有CO₂净释放效应的化学风化类型。SCW二氧化碳释放通量为（5176 mol/km²/year），约为Ca-Mg硅酸盐风化吸收CO₂的2.5倍，突出了化学风化在碳酸盐沉淀和硫酸盐还原时间尺度上，抑制大气CO₂的关键作用。最后，本研究假设催化剂和运输限制是MRB区域最可能的关键因素。硫酸和溶解的二氧化碳之间的相互作用，竞争性地决定了化学风化反应的类型和速率。

附：英文原文

Title: Chemical weathering in Manas River Basin: Driven by sulfuric acid or carbonic acid

Author: Zhang, Jiaxin, Zhu, Bingqi

Issue&Volume: 2024-10-30

Abstract: Carbonic acid produced by the dissolution of atmospheric and soil CO₂ in water is usually the most dominant catalyst for chemical weathering, but a sulfuric acid-driven phenomenon, different from usual, was found in the orogenic belt watersheds dominated by silicate bedrock. This study, rooted in comprehensive field investigations in the Manas River Basin (MRB) north of the Tianshan Mountains, delves into the mechanisms and impacts of sulfuric and carbonic acid as catalysts driving different types of chemical weathering in the Central Asian Orogenic Belt. Quantitative analyses elucidate that carbonate weathering constitutes 52.4% of the total chemical weathering, while silicate and evaporite account for 18.6% and 25.3%, respectively, with anthropogenic activities and atmospheric precipitation having little effect. The estimated total chemical weathering rate in MRB is approximately 0.075×106 mol/km2/year. Quantitative findings further suggest that, preceding carbonate precipitation (<104 year), chemical weathering can absorb CO₂. Subsequently, and following carbonate precipitation (104–107 year), it will release CO₂. The release significantly surpasses the global average CO₂ consumption, contributing to a noteworthy climate impact. This study underscores the distinctive weathering mechanisms, wherein sulfuric acid emerges as the predominant catalyst. The quantity of sulfuric acid as a catalyst is approximately three times that of carbonic acid. Sulfuric acid-driven carbonate rock weathering (SCW) is identified as the sole chemical weathering type with a net CO₂ release effect. SCW CO₂ release flux (5176 mol/km2/year) is roughly 2.5 times the CO₂ absorption by Ca–Mg silicate weathering, highlighting the pivotal role of chemical weathering in sourcing atmospheric CO₂ over the timescales of carbonate precipitation and sulfate reduction. Lastly, this study posits that catalyst and transport limitations are the most plausible critical factors in MRB. The interplay between sulfuric acid and dissolved CO₂ competitively shapes the types and rates of chemical weathering reactions.

DOI: 10.1007/s11631-024-00737-8

Source: https://link.springer.com/article/10.1007/s11631-024-00737-8