Evaluation of heavy metal pollution and their magnetic indicators in beach surface sediments in Rizhao City

Seven heavy metal elements （Cr, Ni, V, Fe, Zn, Co, Pb） are tested for the surface sediments of the Taoluo Town beach, Rizhao City, southern Shandong Province. The geoaccumulation index method is adopted to evaluate the pollution status by heavy metals. At the same time, Both the in-situ magnetic susceptibility （ \mathrm\kappa ） and indoor magnetic parameters tests are carried out with the magnetic parameters of the surface sediments. The results show that the overall pollution situation of the study area is quite weak, all are non-polluted or lightly polluted by heavy metal elements, and the sources of heavy metal pollution occur mainly in estuaries and on beaches. The distribution characteristics of the field volume magnetic susceptibility κ and indoor mass magnetic susceptibility \mathrm\chi are consistent with the distribution pattern of heavy metal content. The grain type of magnetic particles is multi-domain （MD）, and the magnetic minerals are dominated by ferrimagnetic minerals. Based on the high positive correlation between χ and heavy metal content, a magnetic diagnostic method for heavy metal pollution in the study area is proposed.