南黄海西北部SYS-0803孔第四纪晚期底栖有孔虫群落特征及其古环境意义

SYS-0803孔取于南黄海西北部(35°02'N、121°45'E,水深49.00 m),其60.30 m长的柱状样记录了约140 ka以来的沉积环境演变。对248个样品中25个底栖有孔虫变量的Q型因子分析得到4个主因子,累计方差贡献为93.0%。通过底栖有孔虫组合分析,在140 ka以来的沉积中共发现4个海相层和4个陆相层,其中MIS 6晚期海侵层(孔深53.06~50.28 m)中以含典型暖水底栖有孔虫为特征,推测该时期可能存在有暖流;MIS 5e期高海面海相层(孔深33.76~30.55 m)中的微体化石群以典型的冷水底栖有孔虫和介形虫占优势,推断当时的黄海与现代一样,发育有强盛的冷水团。在冰后期海侵层位中发现了以短期海退为特征的YD事件(孔深13.80~12.91 m,12 460~11 572 cal.aBP)。

LATE QUATERNARY BENTHIC FORAMINIFERA OF CORE SYS-0803 FROM THE NORTHWESTERN SOUTH YELLOW SEA AND THEIR PALEOENVIROMENTAL SIGNIFICANCE

The Core SYS-0803 was taken from the northwestern South Yellow Sea (35°02' N,121°45' E,water depth 49.00 m, core length 60.30 m), and it recorded the paleoenvironmental changes of the past~140 ka. Q-mode factor analysis was carried out for 248 samples and 25 benthic foraminiferal species, and 4 varimax factors were selected, which account for more than 93.0% of the total variance. Based on the benthic foraminiferal assemblages, four marine and four terrestrial strata were recognized in this core. The late MIS 6 marine layer (depth 53.06~50.28 m) contains typical warm-water benthic foraminifera, implying the occurrence of a warm current. The MIS 5e (depth 33.76~30.55 m) marine layer was remarked by the abundant cold-water benthic foraminifera and ostracods, indicating the development of a strong cold-water mass similar to the modern Cold-water Mass of the Yellow Sea. A short regression (depth 13.80~12.91 m, 12 460~11 572 cal.aBP)was found in the postglacial transgression layer, probably responding to the Younger Dryas event.