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本研究的长期目标是了解与Kerguelen地幔柱有关的~115 Ma火山活动记录的起源和演化。凯尔盖朗地幔柱特别重要，因为：1）它是长期存在的; 2）与地幔柱有关的火山活动的所有方面都可以进行研究; 3）熔岩具有独特的地球化学特征，可能反映地壳再循环进入深部地幔;大火成岩省的形成（凯尔盖朗高原）在新形成的印度洋可能使这些羽流地球化学特征分散到印度洋软流层。 这项建议旨在扩大目前的项目，包括最近（40马）火山喷发的历史，这是记录在一个厚厚的序列的洪水玄武岩的主要体积单位的凯尔盖朗群岛。 这些熔岩的化学成分（主要和微量元素丰度）和同位素（He，Sr，Nd，Pb和Os）特征将被确定，以显示熔岩成分如何随时间变化（无论是在相对和绝对的基础上与40 Ar-39 Ar定年控制）和位置在群岛。