Fig. 5
From: Abiotic polycyclic aromatic hydrocarbons originating from the sub-oceanic mantle
Schematic illustration of the proposed inclusion formation model. (a) Generated melt was enriched in C, Al, and Si, containing dissolved C–O–H species, such as CH4, CO, and CO2, along with Fe, Ni, Cu, PGEs (Ir, Pt, and Rh), and S, based on the results of Akizawa et al. 15. (b) The melt is trapped by the Cpx grain, separated into three immiscible phases: silicate melt, sulphide melt, and C–O–H phases. (c) After the melt was trapped in individual inclusions, the C–O–H phase was expelled due to decompression. PGMs and BMS crystallized at temperatures above 1000 ℃. The inclusions remained protected from oxidation in the shallower mantle. (d) Aromatisation of simple C–H molecules occurred in C–O–H fluids. (e) The peridotite was subsequently transported to the surface. Abbreviation: Cpx = clinopyroxene.
