Stable isotope record of DSDP Hole 81-552A in the northeastern Atlantic Ocean

Oxygen and carbon isotope ratios in benthic foraminifers have been determined at 10 cm intervals through the top 59 m of DSDP Hole 552A. This provides a glacial record of remarkable resolution for the late Pliocene and Pleistocene. The major glacial event which marked the onset of Pleistocene-like glacial-interglacial alternations was at about 2.4 m.y. ago. These very high-resolution data do not support the notion of significant Northern Hemisphere glaciation between 3.2 and 2.4 m.y. ago.

针对深海钻探计划（Deep Sea Drilling Project, DSDP）552A钻孔顶部59米的岩芯，研究人员以10厘米间隔对其中底栖有孔虫（benthic foraminifers）的氧、碳同位素比值开展了测定。该数据集为上新世晚期与更新世提供了分辨率极高的冰期记录。标志着类更新世冰期-间冰期旋回起始的重大冰期事件发生于约2.4百万年前。此类高分辨率数据并不支持"3.2至2.4百万年前北半球存在显著冰川作用"这一论点。