Greigite as an Indicator for Salinity and Sedimentation Rate Change: Evidence From the Yangtze River Delta, China

Ferrimagnetic greigite (Fe3S4) is widespread in the sedimentary environment. Despite abundant reports of occurrence marine and lacustrine deposits, its formation mechanisms deltaic deposits remain poorly studied. Here we investigate Holocene Yangtze River delta using granulometric, magnetic geochemical methods. The studied cores consist tidal river, estuary, shallow facies ascending order. greigite?bearing layers are found predominantly accreting flat during transgression stage secondarily regression delta's development. These intervals have a higher total sulfur (TS) content to organic carbon ratios (TS/TOC) suggesting accumulation iron sulfides, including greigite, under reducing estuarine conditions. lower Sr/Ba ratios, comparison facies, indicating salinity Supported by dating results, it suggested that sedimentation rate caused rapid sea?level rise early Holocene, favors preservation greigite. Our results indicate detection provides simple useful tool for inferring changes, hence better understanding heterogeneity depositional processes environments.