Pliocene stable oxygen and carbon isotope record of benthic foraminifera from ODP Site 138-846 in the eastern equatorial Pacific@en

Oxygen and carbon isotope ratios were measured in benthic foraminifers from the entire Pliocene and latest Miocene sections of Site 846, a 180-m section, at a sampling interval of 10 cm. This provides a temporal resolution of about 2500 yr. The documented continuity of the record is excellent. Using the time scale that was developed on the basis of orbital tuning of GRAPE density records, we observed a fairly constant phase relationship between delta18O and variations in the obliquity of Earth's rotational axis. A new numbering scheme for Pliocene isotope stages is proposed. […]本研究对846站位（总剖面长度180米）的上新世至晚中新世全部地层中的底栖有孔虫进行了氧、碳同位素比值测试，采样间隔为10厘米，据此获得的时间分辨率约为2500年。本记录的连续性经证实极佳。基于GRAPE密度记录的轨道调谐所建立的年代标尺，我们观测到δ¹⁸O（delta18O）与地球自转轴倾角变化之间存在近乎恒定的相位关系。本研究提出了一套全新的上新世同位素地层阶编号方案。[……]