The effect of stress on paleomagnetic signals: A micromagnetic study of magnetite's single-vortex response

Plain Language Summary

Magnetic minerals in rocks can record and retain magnetic information  for millions of years. This magnetic information can help us to understand processes like plate tectonics and geomagnetic field behavior in the past.  When rocks experience compressional stresses, these affect the magnetization of the magnetic minerals within them, potentially altering this magnetic information. Previous theoretical studies for the affect of stress used analytical theory, and predicted that stress fields of $>$1000 MPa are required to alter rocks' otherwise stable magnetization. This numerical study has shown that much lower pressures of only $\sim$100 MPa are required to compromise rocks' magnetic recordings. The main reason for this is a change in our understanding of rock magnetic systems.  Previous analytical models  were for elongated particles $<100$ nm in size, as these were thought to be the primary carriers of stable magnetization in minerals. We now know that even larger particles can retain  stable magnetic recordings to high temperatures and over geological time . This study shows that the magnetization of these particles   are less stable than smaller particles when stresses are applied.