南海北部ZHS-176孔古海洋学记录:氧同位素和有机碳

PALEOCEANOGRAPHIC RECORDS OF CORE ZHS-176 FROM THE NORTHERN SOUTH CHINA SEA:OXYGEN ISOTOPE AND ORGANIC CARBON

对南海北部陆坡ZHS-176孔进行浮游有孔虫氧同位素和有机碳的研究,重建了末次冰期以来的古气候演化历史。ZHS-176孔浮游有孔虫氧同位素分析揭示了末次冰期期间的气候波动,如末次盛冰期、Heinrich事件1、Blling-Allerd暖期与新仙女木事件在南海北部陆坡均有响应。同时,在全新世阶段存在3个强降水期和3个弱降水期。ZHS-176孔有机碳以生物成因为主,随着夏季风的增强,陆源物质含量增加,但在3kaBP以后由于华南地区夏季风减弱而导致陆源输入减少。

A coupled approach based on planktonic foraminiferal oxygen isotope and organic carbon from core ZHS-176 in the northern South China Sea slope is adopted to reconstruct the history of paleoclimatic evolution since the last glacial stage.The planktonic foraminiferal oxygen isotopic oscillations in core ZHS-176 during the last glacial period are coeval with climatic variations recorded in the Greenland ice core and Western Pacific sediment.These variations include the Last Glacial Maximum,Heinrich event 1,Blling-Allerd,and Younger Dryas.During the Holocene,we also find three periods of strong precipitation stages and three periods of weak precipitation stages.The oxygen isotopic record exhibits correlation with climate records from distant regions,including the high-latitude area of North Atlantic,providing evidence for global tele-connection among regional climates.The biogenic organic carbon is dominated in core ZHS-176,and the content of terrigenous one increases while the East Asian summer monsoon strengthens.But after 3 kaBP,the terrigenous input decreases because of the weakened East Asian summer monsoon in the South China region.