Some recently-formed volcanoes in New Zealand have captured a “geomagnetic excursion”, or a change in the Earth’s magnetic field.
Based on documented rates of change of paleomagnetic field direction during excursions this implies that the volcanoes may have all formed within a period of only 50–100 years or less.
That would be interesting, because we didn’t know of any massive magnetic field changes in that time. If they happened so recently, this implies a whole stack of new geology to learn about, including mechanisms for changing the magnetic fields themselves.
I hope that this does get followed through, as it implies a lot of unrealised changes engraved in the rocky record for us to discover.