Aragonite content, stable oxygen isotopes of Globigerioides ruber, and age of ODP Site 166-1006 sediments

The 1.4-m.y.-long stable oxygen isotope record of Site 1006 in the low-latitude North Atlantic Ocean shows large glacial/interglacial amplitude changes caused by a combination of temperature and salinity fluctuations. A trend of increased sea-surface temperatures during the interglacial periods is present in the record beginning at isotopic Stage 11 and ultimately leading to the lightest d18O values in isotopic Stages 9, 5, and 1. Maximum d18O values are recorded during glacial isotopic Stages 6 and 8. Stable isotopic variability increased during the Brunhes Chron at the 100-ka time scale. The large amplitude changes can best be explained by global and regional ocean circulation changes. Increased strengthened return flow of warm salty water from the Pacific may have occurred during interglacial periods since isotopic Stage 11, which was largely reduced during glacial periods. The large climate fluctuations had a profound effect on the shallow-water carbonate production of the Great Bahama Bank. The aragonite content of the sediments shows fluctuations that follow the d18O record. The leeward side of the Great Bahama Bank received increased input of platform material during sea-level highstands when the sea-surface waters were warm.北大西洋低纬度海域1006站位的140万年尺度稳定氧同位素（stable oxygen isotope）记录，揭示了由温度与盐度波动共同驱动的显著冰期-间冰期振幅变化。该记录自同位素阶段11起便显现出间冰期海表温度升高的演化趋势，并最终在同位素阶段9、5与1中达到d18O的最低值；冰期同位素阶段6与8则对应d18O的最高值。在布容正向极性时（Brunhes Chron）期间，稳定同位素的变异性以10万年的时间尺度显著增强。这类显著的振幅变化可通过全球与区域尺度的海洋环流变迁得到最佳解释：自同位素阶段11以来，间冰期时源自太平洋的暖盐水回流可能得到增强，而该回流在冰期时大幅减弱。剧烈的气候波动对大巴哈马滩（Great Bahama Bank）的浅水碳酸盐沉积产出造成了深远影响。沉积物中的文石（aragonite）含量呈现出与d18O记录相契合的波动特征。当海表水温较高的海平面高水位期时，大巴哈马滩的背风侧会接收更多的台地物质输入。