Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Solid Earth
Was the Eoarchean magnetic field as strong and stable as Earth’s magnetic field today? This question is challenging because the complex geological history of Archean rocks may have altered the magnetic field record.
Nichols et al. [2024] present a compelling study of banded iron ore formations (BIF) from the Isua Supracrustal Belt of southwest Greenland, which has experienced three thermal events and shows a 3.7-billion-year-old (Ga) magnetic record based on paleomagnetic field tests combined with petrological and geochronological lines of evidence.
This study highlights current challenges in recording the strength and stability of the Earth’s magnetic field throughout Earth’s history. The presented Eoarchean paleointensity records from the BIF (>15 mT) were lower than today (>25 mT) but confirm that Earth’s magnetic field has been active since the Eoarchean.
Citation: Nichols, C. I. O., Weiss, B. P., Eyster, A., Martin, C. R., Maloof, A. C., Kelly, N. M., et al. (2024). Possible Eoarchean records of the geomagnetic field preserved in the Isua Supracrustal Belt, southern west Greenland. Journal of Geophysical Research: Solid Earth, 129, e2023JB027706. https://doi.org/10.1029/2023JB027706
—Agnes Kontny, Associate Editor, JGR: Solid Earth