A time-resolved paleomagnetic record of Main Group pallasites: Evidence for a Psyche-like parent body

The Main Group (MG) pallasites are all thought to originate from the same planetesimal (Greenwood et al., 2006). Temporal variations in core dynamo activity on this parent asteroid have been shown by several paleomagnetic studies. For instance, Tarduno et al. (2012) found the first evidence for dynamo activity recorded by magnetic inclusions in olivine crystals from the Imilac and Esquel pallasites. This observation was supported by a paleomagnetic study of the cloudy zone in the Imilac and Esquel pallasites (Bryson et al., 2015). Both studies retrieved paleointensities of ∼100 μT, interpreted as evidence for an active dynamo ∼140-240 Myr after parent body accretion. An active thermal dynamo is predicted to have only lasted for a maximum of ∼40 Myr after accretion (Bryson, Neufeld, et al., 2019;Dodds et al., 2021;Elkins-Tanton et al., 2011). Therefore, this measured magnetic remanence has instead been attributed to compositional convection resulting from core solidification. A subsequent paleomagnetic study of the cloudy zone in the Marjalahti and Brenham pallasites found no evidence of an active dynamo ∼100-120 Myr after accretion (Nichols et al., 2016). Dynamo initiation and the onset of core solidification was therefore predicted to occur between the time at which Brenham and Marjalahti, and subsequently Imilac and Esquel, acquired their paleomagnetic records.

show abstract

“…All data associated with this study are available on Zenodo (https://doi.org/10.5281/zenodo.4672000) (Nichols et al., 2021).…”

Section: Data Availability Statementmentioning

confidence: 99%

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

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

A time-resolved paleomagnetic record of Main Group pallasites: Evidence for a Psyche-like parent body

Cited by 1 publication

References 2 publications

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

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

Contact Info

Product

Resources

About