Interpretation of Anhysteretic Remanent Magnetization Carriers in Magnetofossil‐Rich Marine Sediments

The anhysteretic remanent magnetization (ARM) is an important magnetic parameter for quantifying the concentration of “fine”, mostly sub-micron ferrimagnetic particles in rocks and sediments. A sound understanding ARM carriers needed to interpret environmental information sedimentary archives. This often not achieved marine sediments, which routinely contain several mineral components. Here, we analyze sediment records over different timescales four cores from Eastern Pacific Ocean (Hole 1218A), Antarctic margin (core P4-1), Arctic ARC5-ICE4), South China Sea L07), using coercivity spectra analyses ARM, first-order reversal curve principal component analysis (FORC-PCA), transmission electron microscopy (TEM), unmixing isothermal (IRM) curves. By combining rock TEM results, find that mainly carried by non-interacting single domain (SD) biogenic magnetite (magnetofossils) studied sediments all timescales. Low-coercivity (detrital fine-grained extracellular magnetite) also contribute bulk ARM. Variable magnetofossil chain structures are detected have a significant influence on data interpretation. Quantitative FORC-PCA endmember based quantile contours distributions provide valuable nature endmembers improve We integrated strategy help reduce interpretational ambiguities related future studies.