Origin and Evolution of the Kerguelen Plume: Constraints from Studies of the Kerguelen Archipelago (Collaborative Research)

凯尔盖朗羽流的起源和演化：凯尔盖朗群岛研究的制约（合作研究）

• 批准号: 9417774
• 负责人: Frederick Frey
• 金额: $ 18.23万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-02-15 至 1997-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9417774&HistoricalAwards=false
• 关键词: Origin; Evolution; Kerguelen; Plume; Constraints

Abstract This award supports a project to understand the geochemical evolution of the Kerguelen plume. Mantle plumes are a major vehicle of heat and mass transfer from the Earth's interior. They are also important geochemical windows through which materials and processes of the Earth's interior can be studied. Among mantle plumes, the Kerguelen plume is distinctive because it has created a long (120 million year) magmatic record which included the Kerguelen Plateau, one of the largest oceanic plateaus, the Ninetyeast Rdge, a nearly 5000 kilometer linear chain of volcanoes which formed as the Indian Plate moved northward over the plume, and the Kerguelen Archipelago on the Antarctic plate. This island complex, active from about 40 million years ago to the present, is largely composed of a thick (about 3 kilometers) basaltic plateau lava sequence. This project will undertake detailed geochemical studies of the basaltic rocks on the Kerguelen Archipelago as well as mafic and ultramafic xenoliths occurring in the basaltic lavas. This is a collaboration between Massachusetts Institute of Technology, Woods Hole Oceanographic institution and the University Libre de Bruxelles in Belgium. This collaborative research program is divides into two projects: (1) The Basalt Project is a study of lavas forming stratigraphic sequences in the plateau lavas which are the oldest and most voluminous extrusive unit in the archipelago. The temporal variations in lava compositions and isotopic ratios of strontium, neodymium and lead will be used to determine temporal variations in proportions of mantle source components, characteristics of the melting process, magma supply rates and crustal processing history, and to evaluate various models for the geochemical characteristics of the plume. (2) The Xenolith Project is a study of lower crustal and mantle xenoliths. This research will include petrography, major and trace element abundances and isotopic ratios of minerals. Geoch emical results, including geothermometry, geobarometry, and geochronology, will be used to understand provenance of the xenoliths and to infer the geodynamic environments and geochemical processes which existed during the evolution of the plume. These results of this research will better constrain physical models of the evolution of the Kerguelen plume, specifically, and mantle plumes in general.

摘要该奖项支持一个项目，以了解Kerguelen Plume的地球化学演变。 地幔羽是从地球内部进行热和传质的主要载体。 它们也是重要的地球化学窗户，可以通过这些窗口研究地球内部的材料和过程。 Among mantle plumes, the Kerguelen plume is distinctive because it has created a long (120 million year) magmatic record which included the Kerguelen Plateau, one of the largest oceanic plateaus, the Ninetyeast Rdge, a nearly 5000 kilometer linear chain of volcanoes which formed as the Indian Plate moved northward over the plume, and the Kerguelen Archipelago on the Antarctic plate. 大约4000万年前到现在，这个岛屿复合体主要由厚（约3公里）的玄武岩高原熔岩序列组成。 该项目将对Kerguelen群岛上的玄武岩以及玄武岩熔岩中发生的镁铁质和超镁铁质石进行详细的地球化学研究。 这是马萨诸塞州理工学院，伍兹霍尔海洋学机构和比利时的Libre de Bruxelles之间的合作。 该协作研究计划分为两个项目：（1）玄武岩项目是对高原熔岩中形成地层序列的熔岩的研究，该熔岩是群岛中最古老，最庞大的外来装置。熔岩成分和同位素比率的时间变化将用于确定地幔源成分比例的时间变化，熔融过程的特征，MAGMA供应速率和地壳处理历史的特征，并评估羽绒地理特征的各种模型。 （2）异种石项目是对下地壳和地幔异种石的研究。 这项研究将包括岩石学，主要元素和痕量元素丰度以及矿物质的同位素比。 地理仿真结果，包括地热学，地球计量学和地球文量学，将用于理解异种石的出处，并推断羽流演化过程中存在的地球动力学环境和地球化学过程。 这项研究的这些结果将更好地限制kerguelen羽流的演变的物理模型，特别是地幔羽。