自然杂志 ›› 2025, Vol. 47 ›› Issue (1): 33-39.doi: 10.3969/j.issn.0253-9608.2025.01.004

• 专题 • 上一篇    下一篇

高原剥蚀物质低地再风化调控全球气候变化

郭玉龙,杨博,韩雪,杨守业   

  1. 同济大学 海洋与地球科学学院,海洋地质全国重点实验室,上海 200092
  • 收稿日期:2024-11-11 出版日期:2025-02-25 发布日期:2025-02-20
  • 通讯作者: 郭玉龙 https://mgg.tongji.edu.cn/3a/78/c23347a211576/page.htm
  • 基金资助:
    国家重点研发计划(2022YFF0800504)

The continued weathering of highland erosional materials in lowlands regulates global climate change

GUO Yulong, YANG Bo, HAN Xue, YANG Shouye   

  1. State Key Laboratory of Marine Geology, School of Ocean and Earth Science, Tongji University, Shanghai 200092, China
  • Received:2024-11-11 Online:2025-02-25 Published:2025-02-20

摘要:

大陆硅酸盐风化是构造时间尺度上重要的地质碳汇。高原剥蚀物质低地再风化或异地风化,是指沉积物“从源到汇”系统将造山带抬升剥蚀产生的大量新鲜硅酸盐矿物搬运至气候条件更加适宜的平原地区进行进一步的化学风化,是自然界的“增强风化”碳增汇过程,其主要形式有大河沉积物河漫滩风化、风尘沉积物成土风化以及低海面时期暴露陆架沉积物再风化等。新生代青藏高原隆升背景下,一方面,高原剥蚀物质低地再风化使得化学风化速率在高剥蚀速率下持续响应剥蚀速率的上升,增加了硅酸盐风化对全球变冷的驱动能力;另一方面,高原剥蚀的新鲜矿物大量搬运到低地地区,其化学风化受控于气候动力学因子,对气候变化可以起到负反馈调节作用。因此,高原剥蚀物质的低地再风化是大陆沉积源汇系统调控全球碳循环平衡和气候稳定性的重要机制。建议以“从源到汇”系统观和地球系统科学的思路,在现代过程、地质记录及数值模拟等方面深化对高原剥蚀物质低地再风化的研究,揭示在不同时空尺度上高原隆升及沉积源汇系统演化对全球碳循环和气候变化的调控作用。

关键词: 沉积物, 从源到汇, 硅酸盐风化, 碳循环, 气候变化

Abstract:

Continental silicate weathering is a signifificant geological carbon sink on tectonic timescales. The continued weathering of highland erosional materials in lowlands refers to the process in which large quantities of fresh silicate minerals, generated by uplift and erosion in orogenic belts, are transported to plains with more favorable climatic conditions for further chemical weathering. This represents a natural “enhanced weathering” process, contributing to carbon sequestration. Major forms of this process include the flfloodplain weathering of flfluvial sediments, pedogenic weathering of loess deposits, and the continued weathering of exposed shelf sediments during low sea-level periods. Against the backdrop of the Cenozoic uplift of the Tibetan Plateau, the continued weathering of highland erosional materials in lowlands has allowed chemical weathering rates to sustain their response to increasing erosion rates under high erosion conditions, thereby enhancing the capacity of silicate weathering to drive global cooling. On the other hand, the transport of fresh minerals from highlands to lowlands makes their chemical weathering processes heavily inflfluenced by climatic conditions, providing a negative feedback mechanism for climate change. Therefore, the continued weathering of highland erosional materials in lowlands is a crucial mechanism by which sediment source-to-sink systems regulate global carbon cycle balance and climate stability. It is recommended to deepen research on the continued weathering of highland erosional materials in lowlands from the perspective of “source-to-sink” systems and Earth system science. This can be achieved through studies of modern processes, geological records, and numerical simulations, to uncover the regulatory effects of plateau uplift and sedimentary source-to-sink system evolution on the global carbon cycle and climate change across difffferent spatial and temporal scales.