Major element (wt%), trace element (μg/g), and rare earth element and yttrium (REY, μg/g) compositions of bulk sediments, biogenic apatite, authigenic apatite, and micronodules from core samples GC01 and GC16.

After freeze-drying, the sediment sample was ground in an agate mortar to a particle size of less than 74 μ m (approximately 200 mesh), and 0.05 g of the sample was accurately weighed in a polytetrafluoroethylene dissolution cup for pre-treatment. The main elements were determined using iCAP6300 inductively coupled plasma emission spectroscopy (ICP-OES) produced by Thermo Fisher Scientific; Trace elements were determined using iCAP RQ inductively coupled plasma mass spectrometry (ICP-MS) produced by Thermo Fisher Scientific. Prepare epoxy resin targets from single mineral samples, conduct electron probe analysis for major elements, and after electron probe analysis, use a laser ablation system to perform laser ablation trace element analysis on the same part of the mineral. Process raw data using ICPMSDataCal-12.2.