Understanding the nitrogen (N) isotope ratios of early solar system planetesimals is essential for tracing the origin of Earth's volatiles. The Earth primarily formed from non-carbonaceous (NC) planetesimals in the inner solar system. Magmatic iron meteorites, which sample the metallic cores of these early planetesimals, offer a key proxy for studying this process. Research reveals that NC iron meteorites are distinctly 15N-poor compared to carbonaceous (CC) counterparts, indicating distinct N isotopic compositions between the inner and outer solar system reservoirs.
Experimental data suggest limited nitrogen isotope fractionation during core crystallization and differentiation, affirming that the δ15N values of iron meteorites reflect their parent bodies. Earth's primordial mantle retains 15N-poor signatures, evidencing early accretion of NC planetesimals. These signatures were later modified by mixing with CC materials, explaining Earth's current atmospheric and mantle δ15N values. This research bridges the gap between early solar system processes and the isotopic memory preserved in Earth's mantle and core.
website: popularscientist.com
#EarthVolatiles
#NitrogenIsotopes
#IronMeteorites
#SolarSystemFormation
#PlanetaryScience
No comments:
Post a Comment