Hilton Connor D, Ash Richard D, Piccoli Philip M, Kring David A, McCoy Timothy J, Walker Richard J
Department of Geology, University of Maryland, College Park, Maryland, 20742, USA.
Lunar and Planetary Institute, USRA, Houston, TX, 77058, USA.
Meteorit Planet Sci. 2020 Apr;55(4):771-780. doi: 10.1111/maps.13464. Epub 2020 Apr 9.
Previous studies attributed the origin of metal veins penetrating graphite nodules in the Canyon Diablo IAB main group iron meteorite to condensation from vapor or melting of host metal. Abundances of 16 siderophile elements measured in kamacite within vein and host meteorite are most consistent with an origin by melting of the host metal followed by fractional crystallization of the liquid. The presence of the veins within graphite nodules may be explained by impact, as peak shock temperatures, and thus the most likely areas to undergo metal melting, are at metal-graphite interfaces. The origin of the veins is constrained by Re-Os chronometry to have occurred early (>4 Ga) in Solar System history.
先前的研究将迪亚布罗峡谷IAB主群铁陨石中穿透石墨结核的金属脉的成因归因于主体金属蒸汽的冷凝或熔化。在脉体和主体陨石的铁纹石中测得的16种亲铁元素的丰度，与主体金属熔化后液体的分离结晶成因最为一致。石墨结核中脉体的存在可以用撞击来解释，因为峰值冲击温度以及因此最有可能发生金属熔化的区域位于金属-石墨界面。脉体的成因受铼-锇年代测定法的限制，表明其发生在太阳系历史早期（>40亿年前）。
