TY - JOUR

T1 - Iron-based eutectics, a valuable geological record

AU - Верещагин, Олег Сергеевич

AU - Шиловских, Владимир Владимирович

AU - Камаева, Лариса

AU - Хмельницкая, Майя Олеговна

AU - Горелова, Людмила Александровна

AU - Вапник, Е.А.

AU - Власенко, Наталия Сергеевна

AU - Бритвин, Сергей Николаевич

PY - 2025/7/1

Y1 - 2025/7/1

N2 - Metal iron-based eutectics are common in iron and stony-iron meteorites, where their presence traces space melting of parent celestial bodies or accompanies atmospheric ablation processes. It is less known that the same structures and compositions occur in situ within telluric iron in terrestrial crustal rocks. We have studied iron-based eutectics confined to native iron assemblages in volcanic rocks of Disko Island, Greenland, and combustion metamorphic lithologies of the Hatrurim Complex, Israel. In addition, Fe-P alloys were synthesized, enabling to reconstruct the composition and cooling rates of the initial melt. Despite the different geological settings of the two occurrences, the highly reducing (several units below iron – wüstite buffer) and high-temperature (~1200 ºC) environment results in the appearance of the same P-, C-bearing iron melts, with subsequent rapid crystallization (crystallization speed up to 5 ºC / min) into eutectic structures (iron - cohenite (Fe3C), iron - schreibersite (Fe3P), cohenite - schreibersite and iron - barringerite (Fe2P)). The discovered eutectic structures clearly indicate the possibility of forming iron melt under conditions of low pressure and moderately high temperatures (typical for basalts), which may also be applicable to a number of celestial bodies.

AB - Metal iron-based eutectics are common in iron and stony-iron meteorites, where their presence traces space melting of parent celestial bodies or accompanies atmospheric ablation processes. It is less known that the same structures and compositions occur in situ within telluric iron in terrestrial crustal rocks. We have studied iron-based eutectics confined to native iron assemblages in volcanic rocks of Disko Island, Greenland, and combustion metamorphic lithologies of the Hatrurim Complex, Israel. In addition, Fe-P alloys were synthesized, enabling to reconstruct the composition and cooling rates of the initial melt. Despite the different geological settings of the two occurrences, the highly reducing (several units below iron – wüstite buffer) and high-temperature (~1200 ºC) environment results in the appearance of the same P-, C-bearing iron melts, with subsequent rapid crystallization (crystallization speed up to 5 ºC / min) into eutectic structures (iron - cohenite (Fe3C), iron - schreibersite (Fe3P), cohenite - schreibersite and iron - barringerite (Fe2P)). The discovered eutectic structures clearly indicate the possibility of forming iron melt under conditions of low pressure and moderately high temperatures (typical for basalts), which may also be applicable to a number of celestial bodies.

KW - Cohenite

KW - Eutectic

KW - Iron-wüstite buffer

KW - Native iron

KW - Reduced phases

KW - Schreibersite

UR - https://www.mendeley.com/catalogue/c11e7e05-01b5-3d77-aa96-4d53dbad664f/

U2 - 10.1016/j.lithos.2025.108057

DO - 10.1016/j.lithos.2025.108057

M3 - Article

VL - 504-505

JO - Lithos

JF - Lithos

SN - 0024-4937

M1 - 108057

ER -