Geochemical characteristics and paleoenvironmental implications of major elements in sediments from the continental slope of the Ross Sea, Antarctica since late Pleistocene

Based on the ANT32-RA05C sediment core obtained from the Ross Sea continental slope sector during the 32nd Chinese National Antarctic Research Expedition, major-element geochemistry, the geochemical characteristics, and their paleoenvironmental implications were analyzed. Results show that the ANT32-RA05C core is dominated by poorly-sorted compound glacial-marine sediment, containing a large amount of ice-rafted debris (average 29.76%) and a certain amount of biogenic silica (average 4.81%). Quantitative analysis of elements shows that the distribution pattern of major elements in core follows SiO₂＞Al₂O₃＞Fe₂O₃＞Na₂O＞K₂O＞MgO＞CaO＞TiO₂＞P₂O₅＞MnO. Clearly, the most abundant major element is Si, coming mainly from terrigenous debris (quartz) and siliceous biogenic deposit (biogenic silica). Data of Si and Ca XRF element scanning show good correlation with quantitative analysis results thus could be used for high-resolution environmental research. Combining with environmental indicators, we found that the changes in element content have a good relationship with the Antarctic climate since the end of MIS 7 of late Pleistocene, reflecting mainly the control of climate on provenance and environment. A warming climate usually causes enhanced iceberg inputs and primary productivity, and vice versa in a cooling climate. This study provides a valuable information to reconstruct the paleoclimate and understand the climate evolution of the Ross Sea in the Antarctic region.