Primordial formation of major silicates in a protoplanetary disc with homogeneous 26 Al/ 27 Al
| Autor: | Tu-Han Luu, Tim Elliott, Christopher D. Coath, Timothy Gregory, Sara S. Russell |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Solar System Multidisciplinary Radiogenic nuclide Olivine 010504 meteorology & atmospheric sciences Astronomy SciAdv r-articles engineering.material 010502 geochemistry & geophysics 01 natural sciences Astrobiology Meteorite 13. Climate action Homogeneous Protoplanetary disc engineering Isotopes of magnesium Research Articles Earth (classical element) Research Article 0105 earth and related environmental sciences |
| Zdroj: | Science Advances Gregory, T, Luu, T, Coath, C D, Russell, S S & Elliott, T 2020, ' Primordial formation of major silicates in a protoplanetary disc with homogeneous 26Al/27Al ', Science Advances, vol. 6, no. 11, eaay9626 . https://doi.org/10.1126/sciadv.aay9626 |
| ISSN: | 2375-2548 |
| DOI: | 10.1126/sciadv.aay9626 |
| Popis: | Primordial refractory silicates record evidence that aluminum-26 was efficiently mixed across different solar system sources. Understanding the spatial variability of initial 26Al/27Al in the solar system, i.e., (26Al/27Al)0, is of prime importance to meteorite chronology, planetary heat production, and protoplanetary disc mixing dynamics. The (26Al/27Al)0 of calcium-aluminum–rich inclusions (CAIs) in primitive meteorites (~5 × 10−5) is frequently assumed to reflect the (26Al/27Al)0 of the entire protoplanetary disc, and predicts its initial 26Mg/24Mg to be ~35 parts per million (ppm) less radiogenic than modern Earth (i.e., Δ′26Mg0 = −35 ppm). Others argue for spatially heterogeneous (26Al/27Al)0, where the source reservoirs of most primitive meteorite components have lower (26Al/27Al)0 at ~2.7 × 10−5 and Δ′26Mg0 of −16 ppm. We measured the magnesium isotope compositions of primitive meteoritic olivine, which originated outside of the CAI-forming reservoir(s), and report five grains whose Δ′26Mg0 are within uncertainty of −35 ppm. Our data thus affirm a model of a largely homogeneous protoplanetary disc with (26Al/27Al)0 of ~5 × 10−5, supporting the accuracy of the 26Al→26Mg chronometer. |
| Databáze: | OpenAIRE |
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