Scholarlink

<p>Metasomatized lithospheric mantle plays a critical role in the petrogenesis of CO<sub>2</sub>-rich magmas, which are important hosts of rare-earth element deposits. However, the relationship between the structure of the lithosphere and the global distribution of CO<sub>2</sub>-rich magmas remains poorly quantified. Here we analyse the locations of young (&lt;200 million years ago) continental intraplate CO<sub>2</sub>-rich silicate magmas and magmatic carbonatites in conjunction with upper-mantle shear-wave velocity anomalies and lithospheric thickness estimates. Our results document systematic increases in lithospheric thickness with estimated magma CO<sub>2</sub> content from basanites (&lt;5 wt% CO<sub>2</sub>), which erupt through seismically slow and thin non-cratonic lithosphere, to nephelinites, melilitites and ultramafic lamprophyres, which occur within progressively faster, thicker lithosphere and, finally, to lamproites and kimberlites (&lt;20 wt% CO<sub>2</sub>), which are emplaced on thick cratonic lithosphere. Carbonatites are associated with lithospheric thicknesses similar to those of nephelinites, melilitites and ultramafic lamprophyres, implying the derivation of carbonatites from these mafic CO<sub>2</sub>-rich silicate magmas via liquid immiscibility and/or fractional crystallization. We illustrate our lithospheric thickness–magma type relationship using Cretaceous–Pleistocene alkaline magmatism across western North America, ultimately demonstrating how lithospheric thickness controls the global occurrence of CO<sub>2</sub>-rich magmas and, consequently, their associated rare-earth element deposits.</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

The global distribution of CO2-rich magmas is determined by lithospheric thickness

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年5月22日

查看全文
  • Emilie E. Bowman,
  • Sally A. Gibson,
  • Siyuan Sui,
  • Sergei Lebedev

摘要

Metasomatized lithospheric mantle plays a critical role in the petrogenesis of CO2-rich magmas, which are important hosts of rare-earth element deposits. However, the relationship between the structure of the lithosphere and the global distribution of CO2-rich magmas remains poorly quantified. Here we analyse the locations of young (<200 million years ago) continental intraplate CO2-rich silicate magmas and magmatic carbonatites in conjunction with upper-mantle shear-wave velocity anomalies and lithospheric thickness estimates. Our results document systematic increases in lithospheric thickness with estimated magma CO2 content from basanites (<5 wt% CO2), which erupt through seismically slow and thin non-cratonic lithosphere, to nephelinites, melilitites and ultramafic lamprophyres, which occur within progressively faster, thicker lithosphere and, finally, to lamproites and kimberlites (<20 wt% CO2), which are emplaced on thick cratonic lithosphere. Carbonatites are associated with lithospheric thicknesses similar to those of nephelinites, melilitites and ultramafic lamprophyres, implying the derivation of carbonatites from these mafic CO2-rich silicate magmas via liquid immiscibility and/or fractional crystallization. We illustrate our lithospheric thickness–magma type relationship using Cretaceous–Pleistocene alkaline magmatism across western North America, ultimately demonstrating how lithospheric thickness controls the global occurrence of CO2-rich magmas and, consequently, their associated rare-earth element deposits.