Weak Magnetic Fields in the Outer Solar Nebula Recorded in CR Chondrites
Name
JGR Planets - 2020 - Fu - Weak Magnetic Fields in the Outer Solar Nebula Recorded in CR Chondrites.pdf
Description
Published version
Size
5.53 MB
Format
Adobe PDF
Checksum (MD5)
daf43b64c318dfe248be787cd3e2fd78
Author(s)
Fu, Roger R
Kehayias, Pauli
Weiss, Benjamin P
Schrader, Devin L
Bai, Xue‐Ning
Simon, Jacob B
Date Issued
April 30, 2020
Journal
Journal of Geophysical Research: Planets
Publisher
American Geophysical Union
Citation
Fu, R. R., Kehayias, P., Weiss, B. P., Schrader, D. L., Bai, X.-N., & Simon, J. B. (2020). Weak magnetic fields in the outer solar nebula recorded in CR chondrites. Journal of Geophysical Research: Planets, 125, e2019JE006260.
Version
Final published version
Abstract
Theoretical investigations suggest that magnetic fields may have played an important role in driving rapid stellar accretion rates and efficient planet formation in protoplanetary disks. Experimental constraints on magnetic field strengths throughout the solar nebula can test the occurrence of magnetically driven disk accretion and the effect of magnetic fields on planetary accretion. Here we conduct paleomagnetic experiments on chondrule samples from primitive CR (Renazzo type) chondrites GRA 95229 and LAP 02342, which likely originated in the outer solar system between 3 and 7 AU approximately 3.7 million years after calcium aluminum-rich inclusion formation. By extracting and analyzing 18 chondrule subsamples that contain primary, igneous ferromagnetic minerals, we show that CR chondrules carry internally non-unidirectional magnetization that requires formation in a nebular magnetic field of ≤8.0 ± 4.3 μT (2σ). These weak magnetic fields may be due to the secular decay of nebular magnetic fields by 3.7 million years after calcium aluminum-rich inclusions, spatial heterogeneities in the nebular magnetic field, or a combination of both effects. The possible inferred existence of spatial variations in the nebular magnetic field would be consistent with a prominent role for disk magnetism in the formation of density structures leading to gaps and planet formation.
MIT Department
Massachusetts Institute of Technology. Department of Earth and Planetary Sciences
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Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1029/2019je006260
