Collaborative RUI: Uranium-Series Constraints on Melting in the Jan Mayen Region

协作 RUI：扬马延地区铀系熔化限制

• 批准号: 1060434
• 负责人: Kenneth Sims
• 金额: $ 11.3万
• 依托单位: University of Wyoming
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1060434&HistoricalAwards=false
• 关键词: Collaborative; RUI; Uranium; Series; Constraints

The Mid-Atlantic Ridge, particularly its segments in the Arctic Ocean north of Iceland, produce new crust that has a trace element-rich geochemical signature that differs from normal mid-ocean ridge basalts. This unusual chemistry is an enigma and its origins are disputed, with some evidence indicating that the lavas are of hotspot origin, but not related to the closest known hotspot which is under Iceland, and other evidence pointing to the melting of trapped subcontinental material resulting from the geologically recent opening of the Greenland Basin 53-55 million years ago. Resolution of this question impacts our understanding of the mantle with implications for other regions along the mid-ocean ridge system that experience anomalous volcanism such as the Azores and Ascension. This research examines geochemically anomalous lavas from Jan Mayen Island on the Kolbeinsey Ridge near Iceland to determine their source and the timing and mechanisms of melt generation and transport. Both in-hand samples and those to be collected on a German high-resolution field mapping cruise to the area will be analyzed for radiogenic isotopes (Sr, Nd, Pb, and Hf) and U-series isotopes. A better understanding of the region under investigation will provide important information about how melting occurs at depth and leads to volcanic activity. Broader impacts of the work include support of an early-career investigator from a group under-represented in the sciences at a women's liberal arts college and training of female undergraduate students in state-of-the-art high-end Uranium series dating techniques. The work also involves extensive international collaboration with Swedish, UK, and German scientists and cross training of students in other laboratories as well as having them participate in an international oceanographic cruise to the Arctic.

大西洋中脊，特别是冰岛以北北冰洋的部分，产生了新的地壳，具有不同于普通大洋中脊玄武岩的富含微量元素的地球化学特征。这种不同寻常的化学物质是一个谜，其起源存在争议，一些证据表明熔岩来自热点，但与最近的已知热点冰岛无关，其他证据表明，5300万至5500万年前格陵兰盆地在地质上最近的开放导致了被困的次大陆物质的融化。这个问题的解决影响了我们对地幔的理解，并对大洋中脊系统沿线经历异常火山活动的其他地区，如亚速尔群岛和阿森松岛，产生了影响。这项研究考察了冰岛附近Kolbeinsey Ridge上Jan Mayen岛的异常熔岩，以确定它们的来源以及熔体产生和运移的时间和机制。无论是手头的样品，还是将在德国高分辨率野外测绘巡航到该地区收集的样品，都将进行放射性同位素(锶、钕、铅和氢)和铀系列同位素的分析。更好地了解正在调查的地区将提供有关深部熔融如何发生并导致火山活动的重要信息。这项工作的更广泛影响包括对一家女子文理学院科学界代表性不足的群体的早期职业调查人员的支持，以及对女本科生进行最先进的高端铀系列测年技术的培训。这项工作还包括与瑞典、英国和德国科学家进行广泛的国际合作，并在其他实验室对学生进行交叉培训，以及让他们参加一次前往北极的国际海洋巡航。