High-Resolution Study of the Magnetic Properties in Marine Sediments Based on Diamond NV Center Magnetometry

Magnetostratigraphic dating has been widely employed for the study of marine sediments, including ferromanganese nodules (MFNs) and ferromanganese crusts (MFCs), using high-resolution rock magnetic microscopy (RMM) techniques. However, these sediments accumulate at extremely slow rates of millimeters per million year (mm/Ma), while previously employed scanning SQUID microscopes (SSM) and Hall probe microscope are limited to sub-millimeter spatial resolution. This constraint has hindered the detailed characterization of these magnetic archives. Recently developed RMM techniques leveraging nitrogen-vacancy (NV) centers in diamond offer higher spatial resolutions, approximately 1 μm for quantum diamond microscope (QDM) and 180 μm for scanning quantum diamond microscope (SQDM). In this study, we employed both techniques to conduct high-resolution magnetic field measurements and imaging on a thin-sectioned MFN sample. The results reveal intricate internal magnetic structures, providing technical support and empirical evidence to advance the analytical precision of magnetostratigraphy in marine sediments.