A first-order statistical exploration of the mathematical limits of Micromagnetic Tomography

Abstract

Obtaining a reliable characteristic remanent magnetization (ChRM) from volcanic rock samples is an important challenge in paleomagnetism. Volcanic rocks acquire a thermoremanent magnetization when they cool in the Earth's magnetic field that is proportional to the direction and strength of the magnetic field at the time of cooling. TRMs of natural rocks are often regarded to be the most reliable data source for geomagnetic field models because of their ability to store information on the paleomagnetic field for thousands to millions of years (e.g., Panovska et al., 2019;Pavón-Carrasco et al., 2021). Full vector ChRMs consist of both directional and intensity information on the past geomagnetic field, but they can generally only be obtained for 10%-20% of volcanic samples carrying TRMs (e.g., Nagy et al., 2017;Tauxe & Yamazaki, 2015). One of the reasons for the low success rates is that only single domain (SD) or pseudo-single domain (PSD) iron oxide grains, typically with diameters <1 μm, are reliable recorders of the Earth's magnetic field. Larger multidomain (MD) grains are