近日，美国加州理工学院Michael P. Lamb团队发现地球沉积物源和汇的全球分布出乎意料。该研究于2025年7月24日发表在《地质学》杂志上。

地球的景观、地球化学循环和沉积记录都是由沉积物从海到海的运输形成的。在气候和构造的影响下，沉积物被固定在侵蚀地貌中，通过可以模糊强迫信号的净绕道带运输，并沉积在汇中，以建立沉积记录。尽管在地球科学中，从海到海的沉积物运输很重要，但这些区域的相对丰度仍未量化，而且地球表面与经典概念模型的相似程度尚未得到检验。

研究组制作了一个全球数据库，其中包含了地球上的碳汇系统。结果表明，地球陆地面积主要是侵蚀区（59%），旁路区（22%）和汇区（19%）较少（分别为18%、6%和76%，包括海洋和南极洲）。高海拔地区更容易受到侵蚀，世界上的低地和大河不成比例地受到沉积作用。世界上的大部分地区都没有被“水-碳-汇”模型所描述；这些地区大多是沙漠或盾牌，没有大量的河流或沉积物运输。

即使在那些确实类似于经典教科书进展的地区，系统在集水区和世界主要河流下游之间也表现出了异常的“水-沉域”变化。虽然“从静止到下沉”的范式仍然是主题，但它无法描述构成世界大部分地区的沉积不活跃地区。

附：英文原文

Title: The unexpected global distribution of Earth’s sediment sources and sinks

Author: Harrison K. Martin, Michael P. Lamb

Issue&Volume: 2025-07-24

Abstract: Earth’s landscapes, geochemical cycles, and sedimentary record are shaped by the source-to-sink transport of sediment. Sediment is sourced in erosional landscapes under the influence of climate and tectonics, transported through net bypass zones that can obscure forcing signals, and deposited in sinks to build the sedimentary record. Despite the importance of source-to-sink sediment transport in Earth science, the relative abundance of these domains remains unquantified, and the extent to which Earth’s surface resembles classic conceptual models has not been tested. Here we produce a global database of Earth’s source-to-sink systems. Results show that Earth’s land area is mostly erosional (59%), with bypass (22%) and sink (19%) domains less common (18%, 6%, and 76%, respectively, including oceans and Antarctica). Higher elevations are likelier to be erosional, with the world’s lowlands and large rivers disproportionately depositional. Large parts of the world are not described by the source-to-sink model; these areas are mostly deserts or shields without substantial rivers or sediment transport. Even in areas that do resemble the classic textbook progression, systems show exceptional source-to-sink domain variability between catchments and down the world’s major rivers. While the source-to-sink paradigm remains useful, it cannot describe the sedimentologically inactive areas that make up much of the world.

DOI: 10.1130/G53289.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G53289.1/659770/The-unexpected-global-distribution-of-Earth-sredirectedFrom=fulltext