吉林大学杨德彬团队近日发现停滞的俯冲板块加速了地球深处的碳循环。相关论文于2025年6月30日发表在《地质学》杂志上。

大量的碳可以被输送到亚弧深度以外的地幔深处，因此很可能在很长一段时间内参与地幔过程。然而，碳在深地幔中的停留时间仍存在争议。自中生代晚期以来，（古）太平洋板块一直停滞在东北亚下方的地幔过渡带（MTZ），主导着MTZ上方的深层碳循环。研究组重建了中生代晚期至新生代早期（古）太平洋板块的碳俯冲通量，揭示了碳在弧下深度以外的运输范围为1.4至14.9 Mt/yr。

同时，对白垩纪-新生代板内玄武岩的Sr−Nd−Pb−Zn同位素数据的分析表明，其地幔源含有0.4−1.4 wt%的来自俯冲板块的再循环碳。随着时间的推移，碳俯冲通量和再循环碳量呈现出类似的趋势，包括三次相应的突然减少和主要碳储层从蚀变的海洋地壳向沉积物的过渡。这两种趋势之间的平均时滞为1700万年，反映了与东北亚停滞板块相关的俯冲碳的停留时间相对较短。这些结果表明，停滞板块可以加速深部碳循环，并对俯冲动力学产生强烈影响。

附：英文原文

Title: A stagnant subducted slab accelerates the deep Earth carbon cycle

Author: Si-Wen Zhang, Feng Wang, Kai-Chen Xing, Yi-Ni Wang, Wen-Liang Xu, De-Bin Yang

Issue&Volume: 2025-06-30

Abstract: Substantial amounts of carbon can be transported into the deeper mantle beyond sub-arc depths and are thus likely to participate in mantle processes over long time scales. However, the residence time of carbon in the deep mantle remains debated. The (Paleo-)Pacific plate has been stagnating in the mantle transition zone (MTZ) beneath northeast Asia since the late Mesozoic, dominating deep carbon cycling above the MTZ. We reconstruct the carbon subduction flux from the (Paleo-)Pacific plate during the late Mesozoic to early Cenozoic, revealing that carbon transported beyond the sub-arc depths range from 1.4 to 14.9 Mt/yr. Meanwhile, analysis of SrNdPbZn isotope data for CretaceousCenozoic intraplate basalts shows that their mantle sources contained 0.41.4 wt% of recycled carbon derived from the subducting slab. Over time, the carbon subduction flux and the amount of recycled carbon exhibit similar trends, including three corresponding abrupt decreases and a transition of the predominant carbon reservoir from altered oceanic crust to sediments. An average time lag of 17 m.y. between the two trends reflects a relatively short residence time for subducted carbon associated with the stagnant slab in northeast Asia. These results indicate that stagnant slabs can accelerate the deep carbon cycle and exert a strong effect on subduction dynamics.

DOI: 10.1130/G53422.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G53422.1/659282/A-stagnant-subducted-slab-accelerates-the-deepredirectedFrom=fulltext