Paleomagnetic Investigation of Pacific Ocean Rises

太平洋海隆的古地磁调查

• 批准号: 8710935
• 负责人: Michael McWilliams
• 金额: $ 8万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-11-15 至 1989-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8710935&HistoricalAwards=false
• 关键词: Paleomagnetic; Investigation; Pacific; Ocean; Rises

The Cretaceous Long Normal Polarity Chron (83-119 Ma) represents a 35 million year 'blind' spot in Pacific basin plate motion models based on marine magnetic anomalies. To constrain the evolution of the Pacific basin. This study will be a detailed paleomagnetic and paleontologic analysis of Cretaceous limestones from ten Pacific DSDP oceanic rise sites. The study differs in a fundamental way from much of the previous Pacific paleomagnetic DSDP studies. Rather than studying basalts and producing a paleolatitude value for a given site at only a single age, the emphasis is on DSDP limestones which would yield several Paleolatitude values corresponding to a range of geologicages during which the limestone was deposited. A key feature of this collaborative research is the development and use of a high-resolution biostratigraphic zonation for planktonic foraminifera studied in thin sections. As a result, the Cretaceous limestones can be dated with increased precision and can be correlated with key biostratigraphic sections previously dated by foraminifera in this section. Using automated facilities of the Stanford Paleomagnetic Laboratory and improved measurement techniques, it will be possible to obtain very rapidly paleolatitude information from various DSDP sites. The results will help to interpret in detail the plate motions in the Pacific during the Cretaceous Long Normal Polarity Event.

白垩纪长正极性年表（83- 119ma）代表了基于海洋磁异常的太平洋盆地板块运动模型中3500万年的“盲点”。来限制太平洋盆地的演化。本研究将对10个太平洋DSDP海洋隆起点的白垩纪石灰岩进行详细的古地磁和古生物学分析。这项研究从根本上不同于以往的太平洋古地磁DSDP研究。与其研究玄武岩并仅在单一时代为给定地点产生古纬度值，不如重点放在DSDP石灰石上，它将产生与石灰石沉积的一系列地质时期相对应的几个古纬度值。这项合作研究的一个关键特征是开发和使用高分辨率生物地层带，用于在薄片上研究浮游有孔虫。因此，白垩纪灰岩的定年精度可以提高，并且可以与该剖面中先前通过有孔虫定年的关键生物地层剖面相关联。利用斯坦福古地磁实验室的自动化设备和改进的测量技术，将有可能从各个DSDP站点非常快速地获得古纬度信息。这些结果将有助于详细解释白垩纪长正极性事件期间太平洋板块的运动。