PALEOENVIRONMENTAL SIGNIFICANCE OF CLAY MINERAL ASSEMBLAGES OF CORE ARC5-M06 ON THE CHUKCHI SEA CONTINENTAL SLOPE SINCE LATE PLEISTOCENE

A gravity core of ARC5-M06 was taken from the Chukchi Sea slope during the Fifth Chinese National Arctic Research Expedition in 2012. All samples were analysed for grain size, ice-raft detritus, clastic minerals, clay minerals, XRF scanning and sediment color features. The stratigraphic framework of the late Pleistocene of the core ARC5-M06 since Marine Isotope Stage (MIS) 3 was established by integration of IRD, color cycles, element cycles, as done previously for other cores. The clay mineral assemblages consist of illite, kaolinite and chlorite with small amount of smectite. Clay mineral assemblages in the core ARC5-M06 were compared with those in the adjacent marginal continental shelf to identify their provenance and transport processes during the Late Pleistocene. Based on the above studies, it is concluded that the clay mineral assemblages in the Chukchi Sea slope sediments were mainly from the East Siberia Sea during MIS3, but from the Mackenzie River in Canada and the Yukong River in the North America Continent through the Pacific water masses during late MIS3. And the clay minerals assemblages in the Chukchi Sea slope sediments were mainly from the the East Siberia Sea source input, but those in the Chukchi Sea basin sediments were mainly from the North American continent source input with much more from the Beaufort sea.