近日，南丹麦大学Don E. Canfield团队研究了大陆风化和颗粒向海洋输送的长期历史。相关论文于2025年9月4日发表在《美国科学院院刊》杂志上。
通过利用过去2000年海洋沉积物中Zr/Al、Rb/Al和Na/Al的历史，研究组探索了从大陆到海洋的化学风化和颗粒运输的长期历史。他们在现代风化环境和现代海洋沉积物的元素行为的背景下解释这些数据。结果发现，从2000万年到大约6.5亿年前，物理侵蚀是有效的，辫状河流有效地将颗粒从陆地输送到海洋。总的来说，化学风化作用不如现在有效，尽管许多容易风化的矿物和今天一样被风化。
研究组认为，在6.5亿年类似现代的深俯冲发生后，风化动力学发生了巨大变化。随着这一发展，地幔动力学通过促进周期性的剧烈俯冲和强烈的造山作用，开始控制化学风化和颗粒向海洋输送的强度。通过对多份地球化学记录的光谱分析，发现在俯冲和造山增强时期，大陆经历净侵蚀期，化学风化期较弱；而在俯冲增强时期，大陆颗粒积累期较强，化学风化期较强。陆地植物的进化和增殖改变了化学风化强度，但对大陆颗粒运输和储存的循环性质影响不大。这些结果可以提供一个框架，以更好地理解过去2000年从大陆到海洋的元素循环的演变。
附：英文原文
Title: Long-term history of continental weathering and particle transport to the sea
Author: Canfield, Don E., Zhang, Shuichang, Mitchell, Ross N., Wang, Xiaomei, Naemi, Amin, Spencer, Christopher J., Zhang, Pengyaun
Issue&Volume: 2025-9-4
Abstract: Here, we explore the long-term history of chemical weathering and particle transport from the continents to the oceans by leveraging the histories of Zr/Al, Rb/Al, and Na/Al in marine sediments over the last 2000 My. We interpret these data in the context of elemental behavior in modern weathering environments and modern marine sediments. We find that from 2000 Mya to ca. 650 Mya, physical erosion was effective, where braided rivers efficiently delivered particles from land to the sea. Overall, chemical weathering was less efficient than now, although many easily weatherable minerals were as weathered as today. We suggest a dramatic change in weathering dynamics after 650 Mya when modern-like deep subduction originated. With this development, mantle dynamics, by promoting periodic vigorous subduction and intense mountain building, began to control the intensity of chemical weathering and particle transport to the oceans. Through spectral analysis of several geochemical records, we find that during times of enhanced subduction and mountain building, continents underwent periods of net erosion and less intense chemical weathering, while during periods of less intense subduction, continents accumulated particles, and chemical weathering was more intense. The evolution and proliferation of land plants changed chemical weathering intensity but had little apparent impact on the cyclic nature of particle transport and storage on the continents. These results could offer a framework to better understand the evolution of elemental cycling from the continents to the oceans over the last 2000 My.
DOI: 10.1073/pnas.2507312122
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2507312122