Paleoclimatic evolution and weathering in the Northern South China Sea during the last 61 kyr BP--Sedimentary records from the coastal zone

Abstract

Abstract The history of silicate chemical weathering is recorded by Marine sediments in the west coastal zone, contains the information of terrigenous climate and environment evolution.in order to constrain the Proxy index and driving mechanism of summer monsoon intensityof the sediments from this core since ~61 Kyr BP, the grain size, clay minerals and elemental geochemistry of sediments from core KZK01 in the coastal zone of the Northern South China Sea have been analyzed. The results showed that the illite crystallinity and smectite/(illite+chlorite) not only reflects the intensity of surface chemical weathering in the source area, but also clearly records the Heinrich event (H5), Younger Dryas event and the cold events since the Holocene, such as 8.2 Ka, 4.2 Ka and 2.8 Ka.The regional East Asian summer monsoon is mainly driven by the summer solar radiation at low latitudes in the northern hemisphere,Cold climate events have a global consistency and may be related to the global impact of high-latitude ice sheets.The paleoclimatic changes since 61 Kyr BP in the Northern South China Sea can be divided into 61kry BP~59.5kry BP、59.5kry BP~49.5kry BP、49.5kry BP~40.5kry BP、and 40.5kry BP~11.5kry BP、11.5kry bp~2 kry BP and 2kry BP to present six stages.In different stages of climate evolution, the alternating characteristics of cold, dry, warm and wet are obvious, with significant stages.