2014/04/04 by Pierre Cartigny, M. Palot, Émilie Thomassot +1 · 1 citation
Earth and Planetary Sciences · #Geological and Geochemical Analysis #Paleontology and Stratigraphy of Fossils #High-pressure geophysics and materials
paper · doi:10.1146/annurev-earth-042711-105259
openalex publication_date 2014/04/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Primarily on the basis of C, N, S, and O stable isotope systematics, this article reviews recent achievements in understanding diamond formation and growth in Earth's mantle. Diamond is a metasomatic mineral that results from either the reduction or oxidation of mobile C-bearing liquids (fluids or melts) that intrude preexisting lithologies (eclogites, peridotites, and metamorphic rocks). This process seems ubiquitous, as it occurs over a large range of depths and extends through time. Diamond-forming carbon derives mainly from the convective asthenosphere. Most of its isotopic anomalies reflect fractionation processes in the lithospheric mantle, which are attributed to diamond precipitation itself and/or a mineralogical control occurring prior to diamond precipitation. Evidence for a mineralogical control would be the decoupling of the 15 N/ 14 N ratios in eclogitic diamond from other tracers of subduction in inclusions in the same diamond. C isotope anomalies related to subduction are rare and are probably best seen in diamonds from the transition zone.