Collaborative Research: The Leading Edge of the Galapagos Hotspot, A New Window into the Mantle

合作研究：加拉帕戈斯热点的前沿，了解地幔的新窗口

• 批准号: 0002818
• 负责人: Dennis Geist
• 金额: $ 8.22万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0002818&HistoricalAwards=false
• 关键词: Collaborative; Research; Leading; Edge; Galapagos

Recommended project is for an integrated marine field and laboratory investigation of the western end of the Galapagos archipelago, with a focus on studying lavas from the submarine western flanks of Fernandina and Cerro Azul volcanoes after mapping them with camera tows and multibeam and side scan sonar. The goal is to define and then sample volcanic products from the leading edge of Galapagos plume, with associated, extensive geochemical and petrological studies that will help define the nature of the Galapagos plume. These samples will be used to test whether magma chemistry from leading-edge plume volcanism indeed best reflects the chemistry of the plume mantle source, whether high 3He/4He does indeed reflect undegassed, deep mantle sources, and also to test whether the unique horseshoe-shaped pattern of Galapagos geochemical variation is due to mantle zonation or is instead related to other geologic processes. The field mapping will determine whether there is a new submarine volcano westward of Fernandina that represents the actual plume leading edge (such as represented by Loihi in the Hawaiian plume volcanism), as suggested by seismic data. This work, on the leading edge of a weak plume, will complement similar studies done at Hawaii, a strong plume, in testing models of plume volcanism and origin.***

建议的项目是对加拉帕戈斯群岛西端进行综合海洋实地和实验室调查，重点是在用拖曳照相机、多波束和侧扫声纳测绘后，研究来自费尔南迪纳火山和塞罗阿苏尔火山海底西侧的熔岩。 目标是确定加拉帕戈斯火山柱前缘的火山产物，然后对其进行取样，并进行相关的广泛的地球化学和岩石学研究，以帮助确定加拉帕戈斯火山柱的性质。 这些样品将被用来测试是否岩浆化学从前缘羽状火山作用确实最好地反映了化学的羽状地幔源，是否高3 He/4 He确实反映了未脱气，深地幔源，并测试是否独特的马蹄形模式的加拉帕戈斯地球化学变化是由于地幔环带或与其他地质过程。 实地测绘将确定费尔南迪纳向西是否有一座新的海底火山，它代表了实际的羽流前缘（如夏威夷羽流火山作用中的洛伊希火山），正如地震数据所表明的那样。 这项工作是在弱羽流的前沿进行的，将补充在强羽流夏威夷进行的类似研究，以测试羽流火山作用和起源的模型。