Inverse magnetic fabrics caused by magnetofossils in the northwestern South China Sea since end of the Last Glacial

The relationships among the abundance of magnetofossils, the ensuing magnetic properties, and the controlling paleoenvironmental factors in marine sediments remain broadly unexplored. Here, we identify magnetofossils in core XB1 from the northwestern South China Sea since the Last Glacial Maximum. Using rock magnetic and electron microscopic data, we propose a model that links the anisotropy of magnetic susceptibility fabric and the abundance of magnetofossils. The magnetofossil concentration in sediments increases significantly during the 14.7-4.7 ka period, which in turn leads to inverse magnetic fabrics and near-horizontal of minimum magnetic susceptibility axes. Further, we show that the abundance of magnetofossils is linked to paleoenvironmental changes in the northwestern South China Sea. The production and preservation of magnetofossils during the 14.7-4.7 ka period is promoted by an intensified East Asian summer monsoon and sluggish deep-water ventilation, while the paucity of magnetofossils after 4.7 ka is attributed to high oxygen content.