Molybdenum isotope evidence for subduction-modified mantle beneath mid-ocean ridges

IF 4.8 1区地球科学 Q1 GEOCHEMISTRY & GEOPHYSICS

Earth and Planetary Science Letters Pub Date : 2025-03-10 DOI:10.1016/j.epsl.2025.119294

Zuxing Chen , Fang-Zhen Teng , Robert J. Stern , Yuxiang Zhang , Jie Li , Zhigang Zeng

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引用次数: 0

Abstract

"Ghost" arc geochemical signatures persistently occur in mid-oceanic ridge basalts (MORBs), yet their origin remains elusive. Here, we identified arc-like heavy Mo isotopic compositions in basalts from the St. Helena plume-influenced southern Mid-Atlantic Ridge. Their heavy Mo isotopic signature (δ^98/95Mo = –0.21 ‰ to +0.11 ‰), along with relatively low (La/Sm)_N, Nb/Zr, Ce/Pb, and Sr-Nd isotope ratios, cannot be explained by interactions of the depleted mantle with recycled crustal or lithospheric mantle materials or the influence of the St. Helena plume on their mantle source. By integrating seismic tomographic images and plate reconstruction models, we interpret these unique geochemical and heavy Mo isotopic signatures to reflect the inputs of fluid-modified mantle produced during the Mesozoic subduction beneath the southwestern Gondwana convergent margin. Our discovery provides crucial evidence for the role of the paleo-subduction-modified mantle in shaping present-day MORB-mantle heterogeneity and sheds light on the formation of ghost-arc signatures in global MORBs.

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来源期刊

Earth and Planetary Science Letters 地学-地球化学与地球物理

CiteScore

10.30

自引率

5.70%

发文量

475

审稿时长

2.8 months

期刊介绍： Earth and Planetary Science Letters (EPSL) is a leading journal for researchers across the entire Earth and planetary sciences community. It publishes concise, exciting, high-impact articles ("Letters") of broad interest. Its focus is on physical and chemical processes, the evolution and general properties of the Earth and planets - from their deep interiors to their atmospheres. EPSL also includes a Frontiers section, featuring invited high-profile synthesis articles by leading experts on timely topics to bring cutting-edge research to the wider community.