@article{Steele:2023:10.1126/sciadv.ade9071,
author = {Steele, SC and Fu, R and Volk, MWR and North, TL and Muxworthy, A and Collins, GS and Davison, T and Brenner, AR},
doi = {10.1126/sciadv.ade9071},
journal = {Science Advances},
pages = {1--13},
title = {Paleomagnetic evidence for a long-lived, potentially reversing martian dynamo at ~3.9 Ga},
url = {http://dx.doi.org/10.1126/sciadv.ade9071},
volume = {9},
year = {2023}
}

Download

TY  - JOUR
AB  - The 4.1-billion-year-old meteorite Allan Hills 84001 (ALH 84001) may preserve a magnetic record of the extinct martian dynamo. However, previous paleomagnetic studies have reported heterogeneous, nonunidirectional magnetization in the meteorite at submillimeter scales, calling into question whether it records a dynamo field. We use the quantum diamond microscope to analyze igneous Fe-sulfides in ALH 84001 that may carry remanence as old as 4.1 billion years (Ga). We find that individual, 100-μm-scale ferromagnetic mineral assemblages are strongly magnetized in two nearly antipodal directions. This suggests that the meteorite recorded strong fields following impact heating at 4.1 to 3.95 Ga, after which at least one further impact heterogeneously remagnetized the meteorite in a nearly antipodal local field. These observations are most simply explained by a reversing martian dynamo that was active until 3.9 Ga, thereby implying a late cessation for the martian dynamo and potentially documenting reversing behavior in a nonterrestrial planetary dynamo.
AU  - Steele,SC
AU  - Fu,R
AU  - Volk,MWR
AU  - North,TL
AU  - Muxworthy,A
AU  - Collins,GS
AU  - Davison,T
AU  - Brenner,AR
DO  - 10.1126/sciadv.ade9071
EP  - 13
PY  - 2023///
SN  - 2375-2548
SP  - 1
TI  - Paleomagnetic evidence for a long-lived, potentially reversing martian dynamo at ~3.9 Ga
T2  - Science Advances
UR  - http://dx.doi.org/10.1126/sciadv.ade9071
UR  - https://www.science.org/doi/10.1126/sciadv.ade9071
UR  - http://hdl.handle.net/10044/1/104916
VL  - 9
ER  - 

Download