第九届青年地学论坛

 As a crucial "sink" for terrigenous material entering the ocean, provenance of sediments within the coastal zone and continental shelf sea regions holds significant scientific importance in the investigation of global material cycling. Environmental magnetism was proved as an effective and rapid approach for sediment source identification. Detail and systematic magnetic measurements were performed for surface sediment samples collected from local small rivers (Tan, Moyang and Jian rivers) of west Guangdong, coastal zone (CZ) and continental shelf (CS) to analyze the contribution of local small watersheds to marine sediments. The results indicate that detrital river input magnetite and hematite are coexisted in both CZ and CS sediments. Compared to CZ sediments, relatively higher concentration of hematite and finer grain size of magnetite are appeared at CS sediments. Magnetic minerals input from the Tan River are transported and deposited on the coastal zone by Guangdong longshore current. Meanwhile, magnetic particles originated from the Moyang and Jian Rivers may be directly transported and deposited at the CS due to their narrow and restricted estuaries. Except for the Pearl River, sources of local small rivers significantly contribute to marine sediments at the coastal zone and continental shelf.
 

Terrigenous input, Magnetic properties, Provenance of marine sediments, Local small rivers, West waters of the Pearl River Estuary