[Rockhounds] Geologists discover rocks with the oldest evidence yet of Earth’s magnetic field.

[Paul]

Geologists discover rocks with the oldest evidence yet
of Earth’s magnetic field. The 3.7 billion-year-old rocks
may extend the magnetic field’s age by 200 million years.
Jennifer Chu | MIT News, April 24, 2024
https://news.mit.edu/2024/geologists-discover-rocks-oldest-evidence-earths-magnetic-field-0424

Ancient Rocks Reveal Earth's Magnetic Field Existed
3.7 Billion Years Ago, Science Alert, April 27, 2024
https://www.sciencealert.com/ancient-rocks-reveal-earths-magnetic-field-existed-3-7-billion-years-ago

The open access paper is:

Nichols, C.I., Weiss, B.P., Eyster, A., Martin, C.R., Maloof,
A.C., Kelly, N.M., Zawaski, M.J., Mojzsis, S.J., Watson,
E.B. and Cherniak, D.J., 2024. Possible Eoarchean records
of the geomagnetic field preserved in the Isua Supracrustal
Belt, southern west Greenland. Journal of Geophysical
  Research: Solid Earth, 129(4), p.e2023JB027706.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2023JB027706

Yours,

Paul H.