A global survey of marine magnetic anomalies to constrain the Late Cretaceous-Eocene time scale

全球海洋磁异常调查以限制晚白垩世-始新世时间尺度

• 批准号: 1535937
• 负责人: Alberto Malinverno
• 金额: $ 24.63万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1535937&HistoricalAwards=false
• 关键词: global; survey; marine; magnetic; anomalies

Part 1The Late Cretaceous-Cenozoic geomagnetic polarity time scale based on the C-sequence magnetic anomalies created by seafloor spreading provides an independent measure that can guide magnetic polarity time scale in sediments and thus its importance to geochronology. Since the time scale based on magnetic anomalies was last attempted over 20 years ago the global data has grown considerably, and detailed finite plate rotations have been determined on several spreading centers. The PI plans to use these new results for time scale information to substantially update the time scale information provided by marine magnetic anomalies by extending the analysis originally done in the S Atlantic to several spreading centers. The results will impact all of geological disciplines that require accurate time scale for the Cretaceous through Tertiary interval. The educational components comprise undergraduate training, workshop for Earth2Class program for K-12 science teachers and outreach at Lamont Open House. Part 2The Late Cretaceous-Cenozoic geomagnetic polarity time scale based on the C-sequence magnetic anomalies created by seafloor spreading provides an independent measure that can guide magnetic polarity time scale in sediments and thus its importance to geochronology. The latest in-depth analysis of marine magnetic anomalies, mostly based on the South Atlantic patterns, was carried out more than twenty years ago. The global marine magnetic anomaly record has since grown considerably, and detailed finite plate rotations have been determined on several spreading centers (Central and SE Indian Ridge, Pacific-Antarctic Ridge, NE Pacific, Central N Atlantic). These new results have not been fully analyzed for time scale information, and magnetic anomalies are presently underutilized. The proposed project is to substantially update the time scale information provided by marine magnetic anomalies by extending the analysis originally done in the S Atlantic to several spreading centers. Advancing the state of the art in dating and correlating past events has significant implications in a wide range of geoscience disciplines. To enhance the broader understanding of the fundamental concepts behind the development of a quantitative geologic time scale and to promote scientific training, the project will support an undergraduate student during a 10-week summer internship at the Lamont-Doherty Earth Observatory. The PI will closely supervise the student in selecting suitable profiles, identifying magnetic anomalies, constructing reversal distance data sets, and preparing a presentation of the results. The PI will also run a workshop on the proposed project in the Earth2Class program, where K-12 science teachers are introduced to research by Lamont scientists. The quantification of deep time will be presented to the general public during the Lamont Open House, an annual outreach event that attracts thousands of visitors.

第一部分：基于海底扩张所产生的C序列磁异常的晚白垩世-新生代地磁极性时标，提供了一个独立的尺度，可以指导沉积物中的磁极性时标，从而在地质年代学中具有重要意义。自从20多年前最后一次尝试基于磁异常的时间尺度以来，全球数据已经有了相当大的增长，并且已经确定了几个扩张中心的详细的有限板块旋转。PI计划将这些新的结果用于时间尺度信息，通过将最初在南大西洋进行的分析扩展到几个扩展中心，来大幅更新海洋磁异常提供的时间尺度信息。这些结果将影响所有需要精确的白垩纪至第三纪时间尺度的地质学科。教育部分包括本科生培训，为K-12科学教师举办的Earth 2Class项目研讨会和拉蒙开放日的外联活动。第二部分：基于海底扩张所产生的C序列磁异常的晚白垩世-新生代地磁极性时标，提供了一个独立的尺度，可以指导沉积物中的磁极性时标，从而在地质年代学中具有重要意义。最近一次对海洋磁异常的深入分析是在20多年前进行的，主要是根据南大西洋的模式进行的。此后，全球海洋磁异常记录大幅增加，并在多个扩张中心（中部和东南印度洋海岭、太平洋-南极海岭、东北太平洋、中北大西洋）确定了详细的有限板块旋转。这些新结果尚未经过时间尺度信息的充分分析，而且磁异常目前未得到充分利用。拟议的项目是通过将最初在南大西洋进行的分析扩展到几个扩展中心，大幅更新海洋磁异常提供的时间尺度信息。推进测年和关联过去事件的最新技术在广泛的地球科学学科中具有重要意义。 为了更广泛地了解定量地质时标发展背后的基本概念，并促进科学培训，该项目将支持一名本科生在拉蒙特-多尔蒂地球观测站进行为期10周的暑期实习。PI将密切监督学生选择合适的配置文件，识别磁异常，构建反转距离数据集，并准备结果演示。PI还将在Earth 2Class计划中举办一个关于拟议项目的研讨会，在那里，K-12科学教师将被拉蒙科学家介绍给研究。深度时间的量化将在拉蒙开放日期间向公众展示，这是一项每年都会吸引数千名游客的外联活动。