Collaborative Research: Scientific Drilling in Hawaii: Physics and Chemistry of Mantle Plumes

该项目包括钻一个600米的先导孔准备 在夏威夷的希洛附近进行了一个4.5公里长的岩心钻探， 使用一种新的方法来表征返回的岩心样品和井场， 一系列现代地球化学、岩石学和地球物理学 技术. 孔的主要目的是获得 几乎连续的，有序的记录海洋产量 火山在其主要的屏蔽建设阶段的长时间间隔， 活动 只有一小部分的输出和历史的任何 通过地表可以到达夏威夷各个火山 暴露在外，这些火山的内部不太可能 只有通过深钻才能暴露出来 要解决的主要科学问题涉及 热点的性质，特别是 它们可能代表的“羽流”，以及上涌物质 与岩石圈和周围的地幔物质相互作用， 时间跨度为105至106年。 这些问题密切相关 与岩浆同位素组成和年龄的性质有关， 在钻孔岩芯中遇到的熔岩， 地球化学时间序列与动力学模型 羽流行为和熔体生成，以开发一个全面的模型 夏威夷热点现象的动力学。 可以通过以下方式解决的其他重大科学问题 研究一个独特的样本套件的排序预期从钻井 上一篇：夏威夷火山活动时间有多长？ 什么 是潜艇-陆上过渡的性质， 海底火山的一部分 有哪些 增长机制和增长速度的夏威夷火山和 由于岩石圈的负荷， 火山？ 海洋火山岩的磁性是什么 岩石的深度和岩石学的功能，以及这些如何联系 到海山附近的磁力调查 什么是热结构 和内部火成岩特征的保存状况 远离裂谷带的夏威夷火山侧翼

This project involves drilling a 600 m pilot hole preparatory to core-drilling a 4.5 km hole in the vicinity of Hilo, Hawaii, and characterizing the returned core samples and well site using an array of modern geochemical, petrological, and geophysical techniques. The principal objectives of the holes is to obtain a nearly continuous, ordered record of the output of an oceanic volcano over a long interval of its main shield-building phase of activity. Only small fractions of the output and history of any individual Hawaiian volcano are accessible through surface exposures and it is unlikely that the interiors of these volcanoes will ever be exposed except by deep drilling. The primary scientific questions to be addressed concern the nature of hot spots, in particular, the composition and origin of the "plumes" they may represent, and how the upwelling material interacts with the lithosphere and surrounding mantle material on time scales of 105 to 106 years. These problems are intimately related to the nature of magma isotopic compositions and ages of the lavas encountered in the drill core, and to invert this geochemical time series in conjunction with dynamical models for plume behavior and melt generation to develop a comprehensive model for the dynamics of the hot spot phenomenon at Hawaii. Other major scientific questions that can be addressed through study of a unique sample suite of the sort expected from drilling include: How long is an individual Hawaiian volcano active? What is the nature of the submarine-subaerial transition and of the submarine section of a major oceanic volcano? What are the mechanisms of growth and the rate of growth of a Hawaii volcano and of subsidence due to the load on the lithosphere from the growing volcano? What are the magnetic properties of oceanic volcanic rocks as a function of depth and petrology and how do these relate to magnetic surveys near seamounts? What is the thermal structure and state of preservation of igneous features in the interiors of the flanks of Hawaiian volcanoes far from rift zones.