Characterization of the HIMU Mantle Source from Noble Gas Isotopes in Volcanic Gas Emissions in Sao Tome (Cameroon Volcanic Line).

ABSTRACT: The source of volcanism in the Cameroon volcanic line remains unresolved. To better constrain the mantle components involved, we measure light noble gas (He-Ne-Ar) isotopes and, for the first time, heavy noble gas (Kr-Xe) isotopes in mantle-derived gases from São Tomé, using high-precision dynamic mass spectrometry (DMS). Our data show that the source of São Tomé volcanism is a plume-like mantle reservoir, which is enriched in ²²Ne relative to nucleogenic ²¹Ne when compared to samples originating from the convecting upper mantle, as represented by Mid-Ocean Ridge Basalts (MORBs). In contrast, the isotopic compositions of helium and xenon appear similar to those of the MORB mantle. DMS analysis of Xe isotopes reveals that volcanic gases are affected by diffusive transp

SUBMITTER: Lastes A 

PROVIDER: S-EPMC12536443 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature