论文部分内容阅读
利用气候替代指标Uk37SST,浮游有孔虫Globigerinoidesruber的δ18O,δ13C,微体古生物种群变化、陆源和生源组分以及沉积物粒径等,对南海北部69孔沉积物进行综合研究.结果表明Uk37SST在冰后期为23.3～26.9℃,在末次盛冰期时为22.2～23.8℃.用浮游有孔虫转换函数法对季节温差进行估算,在冰后期为4.5～7.0℃,在末次冰期为7.0～9.0℃,两种估温法均反映了古气候变化相应的海水表层温度.69柱沉积物地层记录在末次盛冰期浮游有孔虫温带优势种Neogloboguadrinapachyderma和营养种Neogloboguadrinadutertrei丰度一致增加;热带优势种Pulleniatinaobliqueloculata和Globigerinoidesacculifer以及超微化石丰度则相应减少,而冰后期则相反.浮游有孔虫、钙质超微化石组成和数量的改变也为古海洋温度升、降提供了直接的证据.研究还表明南海北部冰后期以河流搬运为主,末次盛冰期时以风力搬运占优势,这反映了冬季风强化.
The 69-well sediments in the northern South China Sea were studied comprehensively by using the weather-replacement indicator Uk37SST, δ18O, δ13C of the planktonic foraminifera Globigerinoidesruber, the variation of microfacies paleontology, the terrestrial and biogenic components, and the sediment particle size. The later period is 23.3 ~ 26.9 ℃, and the last ice age is 22.2 ~ 23.8 ℃ .The seasonal temperature difference is estimated by the planktonic foraminifer transfer function method, which is 4.5-7.0 ℃ in the late ice period, 7.0-9.0 ℃ in the last ice stage, Both estimates of temperature reflect the sea surface temperature corresponding to paleoclimate changes.69 The sediment stratigraphy records consistently increased abundance of Neogloboguadrinapachyderma and nutrient species Neogloboguadrinadutertrei in the last ice age, and the tropical dominant species, Pulleniatina obliqueloculata and Globigerinoidesacculifer As well as the decrease of the abundance of the superficial fossils, while the opposite of the late stage of the ice.The change of composition and quantity of planktonic foraminifera and calcareous microfossils also provide direct evidence for the rise and fall of paleoceanic sea temperature.The study also shows that the northern part of the South China Sea In the latter part of the ice, the river was mainly handled by the river, and the latter was dominated by the wind during the last ice age, which reflected Monsoon strengthened.