Microscale pseudo-Thellier palaeointensity using a Quantum Diamond Microscope

In this study, we present the first full palaeointensity protocol based on quantum diamond microscope (QDM) measurements of the vertical magnetic field component (b_z ) above thin sections of an archaeological ceramic. A key advantage of the QDM approach is that it enables the identification, isolation, and tracking of individual magnetic sources within a thin section, allowing ideal palaeomagnetic recorders to be analysed while excluding poorly behaved contributors that dominate bulk measurements. We invert magnetic moments associated with both near-surface and subsurface magnetic sources from QDM maps, and follow their response to alternating-field demagnetisation and anhysteretic remanent magnetisation (ARM) acquisition. Mean directions derived from these selectively inverted sources closely match bulk measurements obtained using a cryogenic rock magnetometer. We quantify the effects of filtering sources based on inversion quality and magnetic behaviour, and demonstrate that for well-separated dipole-like particles, pseudo-Arai slopes constructed from fitted ARM acquisition and AF demagnetisation curves yield palaeointensity estimates that agree, within uncertainty, with double-heating absolute palaeointensity determinations on sister samples. When combined with micro magnetic modelling constraints on the relationship between ARM and thermoremanent magnetisation, these results demonstrate that QDM-based palaeointensity methods offer a promising route toward high-precision, carrier-selective micropalaeomagnetic analysis at the thin-section scale.