The Characeristics And Provenance Of The Sediment In The Parece Vela Basin Since The Quaternary And Their Environmental Implications

Sediments from Core PV100609, PV090815, PV091101and PV090510in the Parece VelaBasin were anaylizd. The compositon and distribution of sediments type, grain size, clay mineralassemblage and chemistry elements from the cores were investigated. Based on the results, thesources of sediments and transmission mechanism in the Parece Vela Basin were analysed. Thecore PV091101and PV090510were used for magnetic measurements to get their ages, and theeolian dust input into the Parece Vela Basin and variation of deep sea bottom were then analysed.The sediment types in the Parece Vela Basin are siliceous oozes, silicious clay and pelagicclay. The distribution of siliceous oozes and ferromanganese crusts were controlled by the depthof water, the topography and the bottom current in the Parece Vela Basin. Based on the verticalvariation of sediments type, grain size, clay mineral assemblage and chemistry elements,sedimentary characteristics and influencing factors of the four cores were analysed. The sources ofsediments were judged in terms of clay mineral assemblage, chemistry elements and grain size.Analysis on the provenance suggests that the material was mainly derived from volcanic rocks ofKyushu-Palau Ridge and Mariana Arc, and then from central Asia as eolian dust by the East Asianwinter monsoon. As a whole, the material in study area showed a deep sea environment model.Based on paleogeomagnetic dating and provenance by clay mineral, the(illite+chlorite+kaolinite)/smectite in the core PV090510was used as a proxy of Asian eolian andapproach its input into Parece Vela Basin, which showed the aridity of central Asia and intensiveEast Asian winter monsoon since1.95Ma. The fine component (2.4-4.3μ m) of the sediment incore PV091101and fine component (2.8-4.8μ m) of the sediment in core PV090510werechoosed as the proxy of the variation of deep sea bottom. The results show that the deep seabottom in the Parece Vela Basin has evoluated from srong to weak and enhanced subsequently,responsing to the influence by Antarctic bottom flow controlled by global climate change.