(Table 1) Stable-isotopes for foraminifers at DSDP Holes 3-16 and 73-519

A stable-isotope stratigraphy was established for planktonic and benthic foraminifers from upper Miocene-lower Pliocene pelagic sediments from the Mid-Atlantic Ridge. A correlation of stable-isotope and biostratigraphic data with magnetostratigraphic age revealed the following: (1) the late Miocene carbon-isotope shift in the South Atlantic bottom waters was minute compared with the shift reported for other deep-sea locations (Haq et al., 1980), (2) a significant cooling or continental ice-volume increase occurred between 5.7 and 5.2 Ma, and (3) a period of warming or ice-volume decrease followed, with the rate of warming increasing beginning at 4.5 Ma and reaching a climax at 4.3 Ma. The timing of these paleoceanographic events is correlated with the onset and termination of the Messinian salinity crisis in the Mediterranean Sea.

针对取自中大西洋洋脊（Mid-Atlantic Ridge）晚中新世-上新世早期（upper Miocene-lower Pliocene）远洋沉积物（pelagic sediments）中的浮游有孔虫（planktonic foraminifers）与底栖有孔虫（benthic foraminifers），研究人员建立了稳定同位素地层学（stable-isotope stratigraphy）序列。将稳定同位素与生物地层数据（biostratigraphic data）同磁地层年龄（magnetostratigraphic age）进行对比分析后，得到以下结论：（1）相较于其他深海站位报道的相关结果（Haq等，1980），南大西洋底层水（South Atlantic bottom waters）的晚中新世碳同位素偏移（carbon-isotope shift）幅度极微；（2）在5.7 Ma至5.2 Ma期间发生了显著降温或大陆冰量（continental ice-volume）增加；（3）随后出现了一段升温或冰量缩减的时期，升温速率自4.5 Ma起逐渐加快，并在4.3 Ma达到峰值。上述古海洋学（paleoceanographic）事件的发生时序，与地中海（Mediterranean Sea）的墨西拿盐度危机（Messinian salinity crisis）的起始与终止时间具有相关性。