Repository logo

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

Published version

Change log


jats:titleAbstract</jats:title>jats:pSeveral 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).</jats:p>


Funder: FP7 Ideas: European Research Council (FP7 Ideas); Id:; Grant(s): 320750, 312284

Funder: NASA Solar Systems Workings program

Funder: The Geological Society

Funder: Mineralogical Society of Great Britain

Funder: Mineral Physics Group of Great Britain

Funder: Jesus College Cambridge

Funder: Royal Astronomical Society; Id:


paleomagnetism, pallasite meteorites, paleointensity, core dynamo, planetesimal

Journal Title

Journal of Geophysical Research: Planets

Conference Name

Journal ISSN


Volume Title



American Geophysical Union (AGU)
European Research Council (320750)