Constraining the origin of chondrules and tracking the early Solar System history using vanadium, chromium and magnesium isotopes
Lead Research Organisation:
University of Bristol
Department Name: Earth Sciences
Abstract
Chondrules are the major component of the most primitive, chondritic meteorites and so are believed to intrinsically linked to accretion of planetary embryos.
As such, constraining the timing and origin of chondrules is central for understanding the early evolution of the solar system and the formation of planets. My
project, "V-Mg-Cr-Chondrule: Constraining the origin of chondrules and tracking the early Solar System history using vanadium, chromium and magnesium
isotopes", tackles outstanding issues on the timing, location and volatile history of chondrule formation. I will apply the V isotope method to study the location
of chondrule formation, from the influence of solar irradiation, which I will compare with 54Cr systematics (nucleosynthetic anomalies) often taken to track
position in a heterogeneous nebula. Coupled radiogenic Cr (my experience) and Mg (expertise from the host) isotope measurements can further date the
chondrule formation (53Mn-53Cr and 26Al-26Mg short-lived chronology), and Cr and Mg stable isotope measurements further trace their volatile history. This
simultaneous application of three isotope systems offers a novel means to address major current ambiguities in understanding chondrule formation, which gives
significant insights into both earth sciences and astronomy.
As such, constraining the timing and origin of chondrules is central for understanding the early evolution of the solar system and the formation of planets. My
project, "V-Mg-Cr-Chondrule: Constraining the origin of chondrules and tracking the early Solar System history using vanadium, chromium and magnesium
isotopes", tackles outstanding issues on the timing, location and volatile history of chondrule formation. I will apply the V isotope method to study the location
of chondrule formation, from the influence of solar irradiation, which I will compare with 54Cr systematics (nucleosynthetic anomalies) often taken to track
position in a heterogeneous nebula. Coupled radiogenic Cr (my experience) and Mg (expertise from the host) isotope measurements can further date the
chondrule formation (53Mn-53Cr and 26Al-26Mg short-lived chronology), and Cr and Mg stable isotope measurements further trace their volatile history. This
simultaneous application of three isotope systems offers a novel means to address major current ambiguities in understanding chondrule formation, which gives
significant insights into both earth sciences and astronomy.
Organisations
Publications
Jiang Y
(2023)
Tracking and dating incipient melting of a new grouplet of primitive achondrites
in Geochimica et Cosmochimica Acta
Li M
(2024)
NWA 11562: A Unique Ureilite with Extreme Mg-rich Constituents
in The Planetary Science Journal
Ni P
(2024)
Copper isotope fractionation during asteroid core solidification
in Geochemical Perspectives Letters
| Description | We have successfully re-established a high precision method of stable Ni isotope analysis for investigating the history of planetary growth and differentiation. In particular we have explored the puzzling difference between Earth and primitive meteorites in their stable 60Ni/58Ni ratios. We used Ni isotopic analyses of so-called enstatite chondrites and achondrites, that isotopically most closely resemble the Earth of all major meteorite groups. Despite some scatter in the analyses of enstatite achondrites, they show no systematic fractionation of Ni isotopic that might be indicative of an important role for core formation in explaining the difference in 60Ni/58Ni between Earth, enstatite chondrites and primitive meteorites in general. We also experimentally constrained the effect of planetesimal core crystallisation on metal stable isotopic fractionation, using analyses of laboratory experiments that equilibrated solid and liquid iron. We have explored the Ni and Cu isotope system using these experiments. Existing literature data of iron meteorites (the solidified product of core crystallisation) show large variations in 60Ni/58Ni and 65Cu/63Cu that are not predicted by our experimental calibration of equilibrium isotopic fractionation. We infer that diffusive processes play an important role in accounting for this significant discrepancy. We have further determined the Ca isotopic composition of the plantessimal Vesta from measurements on a combination of analyses on its intrusive and extrusive magmatic products. This allowed us to untangle magmatic differentiation from parent body composition. We argue that Vesta has a lower 44Ca/40Ca (~0.83±0.04‰) than either the Earth (0.94‰) or Mars (1.04±0.07‰), suggesting marked heterogeneity of the stable isotope compositions of refractory elements in the nebula disc. |
| Exploitation Route | The fellow has already taken these measurements forward as part of Thousand Talents Professorship to be held in the Chinese University of Geosciences Wuhan, which will involve on-going collaboration with the UK. |
| Sectors | Education Environment |
| URL | https://www.researchgate.net/profile/Ke-Zhu-17 |
| Description | Extra-terrestrial material is of intrinsic interest to the public. As part of this fellowship, Ke has engaged lay audiences with his exciting findings of core crystalisation and planetary growth |
| First Year Of Impact | 2023 |
| Sector | Education |
| Impact Types | Cultural |