Evolution of the Kerguelen Plume: Constraints from Geochemical Studies of Lava Sequences in the Kerguelen Archipelago

凯尔盖朗羽流的演化：凯尔盖朗群岛熔岩序列地球化学研究的制约

• 批准号: 9614532
• 负责人: Frederick Frey
• 金额: $ 19.25万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-01-15 至 1998-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9614532&HistoricalAwards=false
• 关键词: Evolution; Kerguelen; Plume; Constraints; Geochemical

9614532 Frey The long-term goal of this research is to understand the origin and evolution of the ~115 Ma record of volcanism related to the Kerguelen mantle plume. The Kerguelen plume is particularly important because:1) it is long-lived; 2) all aspects of plume-related volcanism are accessible for study; 3) lavas have a distinctive geochemical signature that may reflect recycling of crust into the deep mantle; and d) formation of the large igneous province (Kerguelen Plateau) in the newly formed Indian Ocean may have enabled dispersal of these plume geochemical characteristics into the Indian Ocean asthenosphere. This proposal seeks to extend the current project to include the recent (40 Ma) volcanic history of this plume that is recorded in a thick sequence of flood basalts which are the major volumetric unit of the Kerguelen archipelago. The chemical composition (major and trace element abundances) and isotopic (He, Sr, Nd, Pb, and Os) characteristics of these lavas will be determined to show how the lava compositions have changed with time (both on a relative and absolute basis with control by 40Ar-39Ar dating) and location in the archipelago.

9614532 Frey 这项研究的长期目标是了解与凯尔盖朗地幔柱相关的约 115 Ma 火山活动记录的起源和演化。凯尔盖朗羽流特别重要，因为：1）它寿命长； 2) 与羽流相关的火山活动的所有方面都可供研究； 3）熔岩具有独特的地球化学特征，可能反映地壳再循环到地幔深处； d）新形成的印度洋中大型火成岩省（凯尔盖朗高原）的形成可能使这些羽流地球化学特征扩散到印度洋软流圈中。 该提案旨在扩展当前的项目，以包括该羽流的最近（40 Ma）火山历史，该羽流记录在厚厚的溢流玄武岩序列中，这些玄武岩是凯尔盖朗群岛的主要体积单位。 将确定这些熔岩的化学成分（主要元素和微量元素丰度）和同位素（He、Sr、Nd、Pb 和 Os）特征，以显示熔岩成分如何随时间变化（在相对和绝对基础上）。由 40Ar-39Ar 测年控制）和群岛中的位置。