Enigmatic carbon isotopic variability in the oceanic upper mantle.

ABSTRACT: Unraveling the origin(s) of carbon on Earth has remained challenging, not only because of the multiple isotopic fractionation episodes that may have occurred during planet formation processes but also because the end point of these processes, the current isotopic value of Earth's deep carbon reservoirs remains poorly constrained. Here, we present carbon isotopic measurements on rare undegassed mid-ocean ridge basalts from the Pacific, Atlantic, and Arctic Oceans that have preserved the isotopic signature of their mantle source. We find that Earth's present-day convecting upper mantle has variable δ¹³C value from ~-10 to -4‰, significantly different from the δ¹³C value of peridotitic diamonds and with the highest values being restricted to the Atlantic. Evidence for si

SUBMITTER: Moussallam Y 

PROVIDER: S-EPMC12207464 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature