Scholarlink

<p>How oceanic crust forms and intraplate volcanism arises remains central to resolving the mechanisms driving Earth’s dynamic evolution. Anomalously thick oceanic crust is conventionally attributed to thermal mantle plumes, yet large igneous provinces such as the Azores Plateau, with its 8–30 km thick crust, dispersed volcanism, and distinctive water-rich geochemical signatures, challenge this paradigm. Here we use geodynamic numerical models to show that a migrating ridge over a locally hydrated layer (0.1–0.4 wt.% H₂O), generated by dehydration of the Mantle Transition Zone (MTZ), can trigger upwelling and melting sufficient to produce a 10–20 km-thick crust. This mechanism accounts for the plateau’s anomalous crustal thickness, long-lived volcanism, and volatile-rich mantle source. We propose that recycled water, a subduction legacy stored in the MTZ, acts as a primary driver of intraplate volcanism, providing an alternative to the classical stationary mantle plume model. This mechanism may also help explain the widespread contamination of large-scale upper mantle domains by subduction-related fluid signatures, as in the DUPAL and South Atlantic domains.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Subduction legacies in the mantle transition zone modulate intraplate oceanic volcanism

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年5月18日

查看全文
  • Jianfeng Yang,
  • Manuele Faccenda,
  • Christine M. Meyzen,
  • Andrea Marzoli,
  • Liang Zhao

摘要

How oceanic crust forms and intraplate volcanism arises remains central to resolving the mechanisms driving Earth’s dynamic evolution. Anomalously thick oceanic crust is conventionally attributed to thermal mantle plumes, yet large igneous provinces such as the Azores Plateau, with its 8–30 km thick crust, dispersed volcanism, and distinctive water-rich geochemical signatures, challenge this paradigm. Here we use geodynamic numerical models to show that a migrating ridge over a locally hydrated layer (0.1–0.4 wt.% H₂O), generated by dehydration of the Mantle Transition Zone (MTZ), can trigger upwelling and melting sufficient to produce a 10–20 km-thick crust. This mechanism accounts for the plateau’s anomalous crustal thickness, long-lived volcanism, and volatile-rich mantle source. We propose that recycled water, a subduction legacy stored in the MTZ, acts as a primary driver of intraplate volcanism, providing an alternative to the classical stationary mantle plume model. This mechanism may also help explain the widespread contamination of large-scale upper mantle domains by subduction-related fluid signatures, as in the DUPAL and South Atlantic domains.