TY - JOUR

T1 - Interaction of iron carbide and sulfur under P–T conditions of the lithospheric mantle

AU - Bataleva, Yu V.

AU - Palyanov, Yu N.

AU - Borzdov, Yu M.

AU - Bayukov, O. A.

AU - Sobolev, N. V.

PY - 2015/7/4

Y1 - 2015/7/4

N2 - Experimental studies were performed in the Fe3C–S system at P = 6.3 GPa, T = 900–1600°C, and t = 18–20 h. The study aimed to characterize the conditions of iron carbide stability in a reduced lithospheric mantle and to reveal the possibility of the formation of elemental carbon by the interaction of iron carbide and sulfur. It was found that the reaction at T < 1200°C proceeds with the formation of a pyrrhotite–graphite assemblage by the following scheme: 2Fe3C + 3S2 → 6FeS + 2C0. The crystallization of graphite at T < 1200°C is accompanied by the generation of sulfide and metal–sulfide melts and via 2Fe3C + 3S2 → 6[Fe–S(melt) + Fe–S–C(melt)] + 2C(graphite)0 reaction. Resulting from the carbon-generating reactions, not only graphite crystallized in sulfide or metal–sulfide melts, but the growth of diamond also takes place. The obtained data allow one to consider cohenite as a potential source of carbon in the processes of diamond and graphite crystallization under the conditions of a reduced lithospheric mantle. The interaction of iron carbide and sulfur under which carbon extraction proceeds may be one of possible processes of the global carbon cycle.

AB - Experimental studies were performed in the Fe3C–S system at P = 6.3 GPa, T = 900–1600°C, and t = 18–20 h. The study aimed to characterize the conditions of iron carbide stability in a reduced lithospheric mantle and to reveal the possibility of the formation of elemental carbon by the interaction of iron carbide and sulfur. It was found that the reaction at T < 1200°C proceeds with the formation of a pyrrhotite–graphite assemblage by the following scheme: 2Fe3C + 3S2 → 6FeS + 2C0. The crystallization of graphite at T < 1200°C is accompanied by the generation of sulfide and metal–sulfide melts and via 2Fe3C + 3S2 → 6[Fe–S(melt) + Fe–S–C(melt)] + 2C(graphite)0 reaction. Resulting from the carbon-generating reactions, not only graphite crystallized in sulfide or metal–sulfide melts, but the growth of diamond also takes place. The obtained data allow one to consider cohenite as a potential source of carbon in the processes of diamond and graphite crystallization under the conditions of a reduced lithospheric mantle. The interaction of iron carbide and sulfur under which carbon extraction proceeds may be one of possible processes of the global carbon cycle.

UR - http://www.scopus.com/inward/record.url?scp=84938503566&partnerID=8YFLogxK

U2 - 10.1134/S1028334X15070077

DO - 10.1134/S1028334X15070077

M3 - Article

AN - SCOPUS:84938503566

VL - 463

SP - 707

EP - 711

JO - Doklady Earth Sciences

JF - Doklady Earth Sciences

SN - 1028-334X

IS - 1

ER -