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，特别是冰岛北部北冰洋的部分，产生了新的地壳，其具有富含微量元素的地球化学特征，与正常的大洋中脊玄武岩不同。 这种不寻常的化学物质是一个谜，其起源存在争议，一些证据表明熔岩是热点起源的，但与冰岛下方最近的已知热点无关，而其他证据则表明被困的次大陆物质的融化是由格陵兰盆地在 53-5500 万年前地质上最近的开口。 这个问题的解决影响了我们对地幔的理解，并对沿大洋中脊系统经历异常火山活动的其他区域（如亚速尔群岛和阿森松岛）产生影响。 这项研究检查了冰岛附近科尔宾塞山脊扬马延岛的地球化学异常熔岩，以确定其来源以及熔体产生和运输的时间和机制。现有样本和德国高分辨率实地测绘巡航到该地区收集的样本都将进行放射性同位素（Sr、Nd、Pb 和 Hf）和 U 系列同位素分析。更好地了解所调查的区域将提供有关深层融化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女子文理学院科学界代表性不足的群体的早期职业调查员的支持，以及对女本科生进行最先进的高端铀系列约会技术的培训。这项工作还涉及与瑞典、英国和德国科学家的广泛国际合作，以及对其他实验室的学生进行交叉培训，以及让他们参加前往北极的国际海洋学航行。