TY - JOUR

T1 - Carbon isotope fractionation during high pressure and high temperature crystallization of Fe-C melt

AU - Reutsky, V. N.

AU - Borzdov, Yu M.

AU - Palyanov, Yu N.

PY - 2015/6/6

Y1 - 2015/6/6

N2 - There is a growing body of experimental evidence that iron carbides can play an important role in the mantle both as a host of carbon and as a redox couple (Fe-C) determining the nature of reduced phases. If carbides are significant in the mantle, it could be of interest to know if any carbon isotope fractionation accompanies carbide crystallization. A series of high-pressure and high-temperature experiments were performed on carbide crystallization from a Fe-C melt. An offset of 2‰ was observed between the δ13C values of Fe3C and Fe-C melt at 6.3GPa and 1400°C. The carbon isotopic compositions of Fe3C and diamond crystallizing from a single carbon source near the peritectic region at 6.3GPa differ by 2.5‰. Fe7C3 was detected as a quench phase during Fe-C melt quenching. Our results have important implications for understanding carbon isotope distributions in iron meteorites and indicate that iron carbide crystallization may be a significant mechanism for carbon isotope heterogeneity in the Earth's mantle.

AB - There is a growing body of experimental evidence that iron carbides can play an important role in the mantle both as a host of carbon and as a redox couple (Fe-C) determining the nature of reduced phases. If carbides are significant in the mantle, it could be of interest to know if any carbon isotope fractionation accompanies carbide crystallization. A series of high-pressure and high-temperature experiments were performed on carbide crystallization from a Fe-C melt. An offset of 2‰ was observed between the δ13C values of Fe3C and Fe-C melt at 6.3GPa and 1400°C. The carbon isotopic compositions of Fe3C and diamond crystallizing from a single carbon source near the peritectic region at 6.3GPa differ by 2.5‰. Fe7C3 was detected as a quench phase during Fe-C melt quenching. Our results have important implications for understanding carbon isotope distributions in iron meteorites and indicate that iron carbide crystallization may be a significant mechanism for carbon isotope heterogeneity in the Earth's mantle.

KW - Carbon isotope fractionation

KW - Crystallization

KW - Diamond

KW - Fe-C melt

KW - HPHT experiment

KW - Iron carbide

UR - http://www.scopus.com/inward/record.url?scp=84928997001&partnerID=8YFLogxK

U2 - 10.1016/j.chemgeo.2015.04.015

DO - 10.1016/j.chemgeo.2015.04.015

M3 - Article

AN - SCOPUS:84928997001

VL - 406

SP - 18

EP - 24

JO - Chemical Geology

JF - Chemical Geology

SN - 0009-2541

ER -