Early/Late Maastrichtian Climatic History of the South Atlantic and Indian Oceans (Marine Geology): VPW

南大西洋和印度洋早/晚马斯特里赫特气候史（海洋地质）：VPW

• 批准号: 9103312
• 负责人: Enriqueta Barrera
• 金额: $ 15.79万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-09-01 至 1994-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9103312&HistoricalAwards=false
• 关键词: Early; Late; Maastrichtian; Climatic; History

Contrary to previous suggestions of uniform, warm and equable climatic conditions during the Late Cretaceous, foraminiferal isotopic results from deep-sea and onshore sequences reveal progressive cooling, and significant climatic and oceanographic variability during the Maastrichtian. Episodes of marked increase in forminiferal values correlate with decreases in specified oceanic 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 values and those of middle Eocene age associate with ice-rafted debris, suggest that these variations might be related to glacioeustatic phenomena. The research proposed will investigate and document the climatic and oceanographic history of the early to late Maastrichtian in the high and mid latitude South Atlantic and Indian Oceans based on foraminiferal oxygen and carbon isotope measurements, and foraminiferal quantitative analyses. Biostratigraphic correlation of deep-sea sections will be enhanced by integration of biostratigraphy, magnetostratigraphy and chemostratigraphy. Evidence of substantial continental ice accumulation in the Maastrichtian will have significant implications for modeling of Cretaceous climates as well as interpretations of climatic history in general. This project should lead to better paleooceanographic reconstructions, relevant to climatic evolution, suggesting when and how certain changes developed. It furthers VPW program objectives to provide opportunities for women to advance their careers in science or engineering through research, and to encourage other women to pursue careers in these areas through the investigators' enhanced visibility as role models on the host campuses. In this project, the proposed activities which contribute to the second objective include: teaching a course in chemical-biotic relations in the fossil record; giving lectures in geologic topics to universities, colleges and high schools near Princeton University to encourage women students to pursue scientific careers; co-teaching a departmental seminar each semester.

与之前认为的晚白垩世气候条件均匀、温暖和均匀相反，深海和陆地序列的有孔虫同位素结果显示，马斯特里赫特时期的气候逐渐变冷，气候和海洋学也发生了显著变化。在马斯特里赫特早期至晚期和晚期，矿物值的显著增加与特定海洋值的降低、记录的海平面回归和海水87Sr/86Sr比值的增加有关。这些事件的巧合，以及马斯特里赫特底栖有孔虫值与始新世中期与冰筏碎屑相关的底栖有孔虫值的相似性，表明这些变化可能与冰川形成现象有关。本研究将在有孔虫氧、碳同位素测量和有孔虫定量分析的基础上，对南大西洋和印度洋高纬度和中纬度马斯特里赫特早期至晚期的气候和海洋学历史进行调查和记录。生物地层学、磁地层学和化学地层学的整合将加强深海剖面的生物地层对比。马斯特里赫特大量大陆冰积累的证据将对白垩纪气候的建模以及一般气候历史的解释具有重要意义。该项目将有助于更好地重建与气候演变相关的古海洋，揭示某些变化发生的时间和方式。它进一步推进了VPW项目的目标，即为女性提供通过研究提升她们在科学或工程领域的职业生涯的机会，并通过研究人员在主办校园中作为榜样的知名度来鼓励其他女性在这些领域追求职业。在这个项目中，建议的有助于第二个目标的活动包括：教授一门关于化石记录中的化学-生物关系的课程；在普林斯顿大学附近的大学、学院和高中举办地质学专题讲座，鼓励女学生从事科学事业；每学期联合教授一个部门研讨会。