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大洋钻探184航次从南海取得了距今32.8 Ma以来的深海沉积记录,其中的渐新世(32.8～23.8Ma)沉积包含丰富的孢粉化石.1148站孢粉分析建立了中国首例深海相渐新统孢粉组合序列.孢粉组合以山地针叶树花粉为优势组分,阔叶树花粉含量较低.二者均以热带、亚热带植物分子为主,但也含山地喜凉、干植物分子.南海深海相渐新统孢粉组合序列在距今32.0 Ma显示明显的变化,反映了南海地区渐新世气候的一次重大转折.孢粉植物群特征表明32.0 Ma以前南海邻近陆地的植被以热带山地雨林和低地雨林为主,南海地区具热而湿润的气候条件;32.0 Ma以后的渐新世孢粉植物群中温带高山针叶树和山地喜温干落叶阔叶树增多,表明此后南海地区的气候变得较为凉干.
Ocean Drilling 184 recorded deep-sea sediments from the South China Sea at 32.8 Ma, of which Oligocene (32.8-23.8 Ma) sediments are rich in sporo-pollen fossils. Sporadic analysis of 1148 stations established the first deep- The sporopollen assemblages are dominated by coniferous pollen from mountainous areas and pollen from broad-leaved trees, both of which are mainly tropical and subtropical plant elements, but also contain mountain xylem and dry plant molecules. The evolution of the Paleocene sporopollen assemblage shows a significant change at 32.0 Ma dating back to a major turning of the Oligocene climate in the South China Sea.The characteristics of the sporopollen assemblages indicate that the vegetation of the adjacent land in the SCS before 32.0 Ma is characterized by the tropical montane rain forest and Lowland rainforests and the South China Sea with hot and humid climatic conditions. The increase of mid-temperate coniferous trees and hi-temperature deciduous broad-leaved deciduous trees in the Oligocene sporopollen assemblages after 32.0 Ma indicate that the climate in the South China Sea has become cooler since then .