Timing and Origin of the Angrite Parent Body Inferred from Cr Isotopes - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles The Astrophysical journal letters Year : 2019

Timing and Origin of the Angrite Parent Body Inferred from Cr Isotopes


Angrite meteorites are some of the oldest materials in the solar system. They provide important information on the earliest evolution of the solar system and accretion timescales of protoplanets. Here, we show that the 54Cr/52Cr ratio is homogeneously distributed among angrite meteorites within 13 parts per million, indicating that precursor materials must have experienced a global-scale melting such as a magma ocean. The 53Cr/52Cr and Mn/Cr ratios are correlated, which is evidence for an initial 53Mn/55Mn ratio of (3.16 ± 0.11) × 10−6 . When anchored to the U-corrected Pb–Pb age for the D’Orbigny angrite, this initial 53Mn/55Mn corresponds to an absolute age of 4563.2 ± 0.3 Ma, i.e., 4.1 ± 0.3 Ma after Ca–Al-rich inclusion-formation. This age is distinct from that of the volatile depletion events dated by the 87Sr/86Sr initial ratio and therefore must correspond to the age of crystallization of the magma ocean and crust formation of the angrite parent body (APB), which can also constrain a slightly bigger size of APB than that of Vesta. Furthermore, this age is similar to those obtained from internal isochrons of the oldest volcanic angrites that cooled rapidly at the surface of the parent body (with ages of 4564 ∼ 4563 Ma), while older than those obtained from plutonic angrites (4561 ∼ 4556 Ma) that cooled down slowly, located deeper within the parent body. This implies that cooling of the APB took at least ∼8 Myr after its differentiation.
Fichier principal
Vignette du fichier
Zhu_2019_ApJL_877_L13.pdf (720.73 Ko) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-02613121 , version 1 (19-05-2020)



Ke Zhu, Frédéric Moynier, Daniel Wielandt, Kirsten K Larsen, Jean-Alix J-A Barrat, et al.. Timing and Origin of the Angrite Parent Body Inferred from Cr Isotopes. The Astrophysical journal letters, 2019, 877 (1), pp.L13. ⟨10.3847/2041-8213/ab2044⟩. ⟨insu-02613121⟩
84 View
59 Download



Gmail Facebook X LinkedIn More