A Time-Resolved Paleomagnetic Record of Main Group Pallasites: Evidence for a Large-Cored, Thin-Mantled Parent Body

Nichols C.I.O. ; Bryson J.F.J. ; Cottrell R.D. ; Fu R.R. ; Harrison R.J. ; Herrero Albillos J. (Universidad de Zaragoza) ; Kronast F. ; Tarduno J.A. ; Weiss B.P.

Resumen: Several paleomagnetic studies have been conducted on five Main Group pallasites: Brenham, Marjalahti, Springwater, Imilac, and Esquel. These pallasites have distinct cooling histories, meaning that their paleomagnetic records may have been acquired at different times during the thermal evolution of their parent body. Here, we compile new and existing data to present the most complete time-resolved paleomagnetic record for a planetesimal, which includes a period of quiescence prior to core solidification as well as dynamo activity generated by compositional convection during core solidification. We present new paleomagnetic data for the Springwater pallasite, which constrains the timing of core solidification. Our results suggest that in order to generate the observed strong paleointensities (~65–95 µT), the pallasites must have been relatively close to the dynamo source. Our thermal and dynamo models predict that the Main Group pallasites originate from a planetesimal with a large core (>200 km) and a thin mantle (<70 km).

Idioma: Inglés

DOI: 10.1029/2021JE006900

Año: 2021

Publicado en: JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS 126, 7 (2021), 006900 [21 pp.]
ISSN: 2169-9097

Factor impacto JCR: 4.434 (2021)

Categ. JCR: GEOCHEMISTRY & GEOPHYSICS rank: 19 / 87 = 0.218 (2021) - Q1 - T1

Factor impacto CITESCORE: 6.6 - Earth and Planetary Sciences (Q1)

Financiación: info:eu-repo/grantAgreement/ES/MCINN/MAT2017-83468-R

Tipo y forma: Article (Published version)

Área (Departamento): Área Cienc.Mater. Ingen.Metal. (Dpto. Ciencia Tecnol.Mater.Fl.)