Maastrichtian Climatic History of the Southern Oceans

初步锶氧碳同位素结果 研究表明，气候逐渐变冷， 以及马斯特里赫特期的海洋变化。 集 有孔虫del 18 O值的显著增加与 海洋del 13 C值下降，记录的海平面 海水中87 Sr/86 Sr比值的增加， 从早到晚和最晚的马斯特里赫特时期。 这些巧合 事件，以及马斯特里赫特底栖动物之间的相似性 有孔虫δ 18 O值与中始新世 与冰筏碎片有关，表明马斯特里赫特时期 同位素变化可能与冰川-海平面升降现象有关。 拟议的研究将调查和记录 高、中纬度气候和海洋史 南大西洋和印度洋从最近的早期 Maastrichtian到第三纪边界的基础上， 有孔虫的氧和碳同位素测量，以及 有孔虫定量分析 我们将试图确定 气候/海洋变化对有孔虫的影响 人口。 深海剖面的地层对比将 通过生物地层学、磁性地层学 和化学地层学 预计这一数据集将提供一个 晚白垩世气候重建的基础包括 开发新的气候模型， 假设统一的，温暖的，和稳定的气候条件， 白垩纪

Results of preliminary strontium, oxygen and carbon isotope studies have revealed progressive cooling, and significant climatic and oceanographic variability during the Maastrichtian. Episodes of marked increases in foraminiferal del 18O values correlate with decreases in oceanic del 13C values, documented sea level regressions, and increases in seawater 87Sr/86Sr ratios in the early to late and latest Maastrichtian. The coincidence of these events, and the similarity between Maastrichtian benthic foraminifera del 18O values and those of middle Eocene age associated with ice-rafted debris, suggest that the Maastrichtian isotopic variations could be related to glacio-eustatic phenomena. The research proposed will investigate and document the climatic and oceanographic history of the high and mid-latitude South Atlantic and Indian Oceans from the latest early Maastrichtian to the Cretaceous-Tertiary boundary based on foraminiferal oxygen and carbon isotope measurements, and foraminiferal quantitative analyses. We will attempt to determine the effect of climatic/oceanographic changes on foraminiferal populations. Stratigraphic correlation of deep-sea sections will be enhanced by integration of biostratigraphy, magnetostratigraphy and chemostratigraphy. This data set is expected to provide a basis for climatic reconstruction of the Late Cretaceous including development of new climatic models that are not based on the assumption of uniform, warm, and equable climatic conditions during the Cretaceous.