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选取大洋钻探ODP130航次在西太平洋暖池钻取的807站A孔上段43m岩芯样品为研究材料,进行浮游有孔虫表层水种、次表层水种的氧、碳稳定同位素分析,并与赤道东太平洋ODP851站的记录比较,揭示了赤道太平洋海区距今2.5Ma以来上部水体的古海洋变迁.研究发现,早更新世1.6～1.4Ma时,赤道东、西太平洋表层水和次表层水的氧同位素都发生明显的分异,进一步证实赤道太平洋类似于现代的东-西向温度梯度(表层水温西高东低)和上部水体温跃层西深东浅的不对称格局在当时最终形成.由于次表层水的氧同位素东-西向梯度变化大于表层水的,说明赤道东、西太平洋这种不对称格局的形成应该与东太平洋温跃层变浅、次表层水显著降温关系更为密切.此外,～1.6Ma之后,赤道太平洋表层水和次表层水的碳同位素差异明显变小,且其偏心率长周期也从400ka变为～500ka,反映了大洋碳储库的改组,可能与这一时期南大洋深部水的改组及其对热带太平洋(特别是次表层海水)的影响加剧有关,说明热带系统可以在全球气候变化中起重要作用.
The core samples of 43m core in the upper section A of the 807 station drilled from the ODP130 ocean voyage in the Western Pacific Warm Pool were selected as the materials for the study. Oxygen and carbon stable isotope analyzes of surface and sub-surface species of planktonic foraminifera were carried out. The comparison of the records of ODP station 811 in the eastern Pacific Ocean revealed the paleoceanographic evolution of the upper water body since 2.5Ma in the equatorial Pacific Ocean.The study shows that during the Early Pleistocene 1.6 ~ 1.4Ma, oxygen in the surface and sub-surface water of the equatorial eastern and western Pacific And the isotopes were obviously differentiated, further confirming that the asymmetric pattern of the equatorial Pacific Pacific Ocean similar to the modern east-west temperature gradient (west-east-low of surface water temperature) and west-east-shallow of the upper thermocline was finally formed at that time. The variation of water oxygen isotope east-west gradient is greater than that of surface water, indicating that the formation of the asymmetric pattern in the equatorial east and west Pacific should be more closely related to the shallowing of the eastern Pacific thermocline and the significant cooling of sub-surface water.In addition, After 1.6Ma, the difference of carbon isotope between surface water and subsurface water in equatorial Pacific decreased obviously, and the long period of eccentricity also changed from 400ka to 500ka, which reflected that the oceanic carbon Reorganization of the library, and may reshuffle the Southern Ocean deep water during this period and its impact on the tropical Pacific Ocean (especially subsurface waters) intensifies related, indicating that tropical systems can play an important role in global climate change.