Supplementary of "Tomofast-x-µ: 3-D Magnetization Reconstruction of Micromagnetic Imaging"

Primary Abstract Traditional paleomagnetic measurements on bulk rock samples average signals from many magnetic grains and cannot resolve spatial variability within a rock. The recent introduction of Quantum Diamond Microscope (QDM) technology to the paleomagnetic community enables the analysis of single-grain records of the geomagnetic field in geological samples. As QDMs become more widely available in paleomagnetic laboratories, better knowledge of the magnetic behavior of single grains or crystals, and comprehensive analytical methods are needed to acquire paleo- and rock-magnetic data more efficiently, comparable to that of bulk-sample methods. In this research, we present a 3D micro-magnetic inversion workflow based on the Tomofast-x inversion code. It consists of three independent tasks: (1) 3D full-magnetization vector inversion; (2) locating magnetic source centers; (3) recovering paleomagnetic information. Our technique is validated using synthetic data covering isolated and overlapping dipole scenarios, compared with an Euler-based inversion code, and subsequently applied to three natural samples with well-separated dipoles, multiple magnetic sources and overlapping linear-geometry dipoles. Tomofast-x-µ yields perfect reconstruction of synthetic data and provides more stable results than the Euler-based technique for overlapping geometries, with more accurate moment intensity estimation. The results demonstrate the code's advantage in providing full 3D inversion of micromagnetic data, yielding magnetic grain locations, shapes, sizes, and magnetization magnitudes within a 3D inversion framework. Furthermore, results from the source location tool demonstrate the algorithm's ability to locate and delineate magnetic dipole sources accurately. The method is shown to be capable of extracting robust paleomagnetic information, including both magnetic direction and moment.