REU: Geologic and Geophysical Study of Mesozoic Guyots

该奖项将支持麻省理工学院的麦克纳特博士参与一项关于位于日本海沟和夏威夷群岛之间的古特人的形态、沉积史和地球化学的研究。众所周知，太平洋的这一区域是独一无二的，其特点是在白垩纪大规模火山活动期间开始形成的众多海山链、环礁和盖约人群岛。在托马斯·华盛顿号上的野外项目期间收集的数据包括反射地震剖面、个别人的重力和磁力，以及这些特征的样本。这些数据将用于审查火山活动的年龄序列、白垩纪太平洋板块运动、岩石圈挠曲和弹性/热厚度、火山岩的地球化学亲和力和地幔来源、海山古纬度、Guyot礁帽的厚度和内部地层学以及珊瑚礁溺水的时间和原因。这些数据将被用来检验这样一种假设，即这条海山链“达尔文带”的较老的西北端在白垩纪被地幔和薄而热的岩石圈类型所支撑，而地幔和薄而热的岩石圈现在位于该带活跃的东南部。这是一个由斯克里普斯研究所、德克萨斯农工大学和麻省理工学院的科学家参与的合作项目。来自该项目的数据将对该地区未来的海洋钻探计划起到重要作用。

This award will support Dr. McNutt of the Massachusetts Institute of Technology to participate in a study of the morphology, sediment history and geochemistry of guyots which are located between the Japan Trench and the Hawaiian Islands. This area of the Pacific Ocean is known to be unique and is characterized by numerous seamount chains, atolls and guyot groups which began forming during a Cretaceous period of extensive volcanism. Data to be collected during a field program aboard the Thomas Washington include reflection seismic profiles, gravity and magnetics across individual guyots as well as sampling of these features. These data will be used to examine questions on the age sequences of volcanism, Cretaceous Pacific Plate motions, lithosphere flexuring and elastic/thermal thickness, geochemical affinities and mantle sources of volcanics, seamount paleolatitudes, thickness and internal stratigraphy of guyot reef caps, and the timing and causes of reef drowning. These data will be used to examine the hypothesis that the older northwest end of this "Darwin Belt" of seamount chains was underlain in Cretaceous times by the type of mantle and thin, hot lithosphere that now underlies the active, southeast part of the belt. This is a cooperative project involving scientist at Scripps Institution, Texas A & M University and the Massachusetts Institute of Technology. Data from this project will be important in planning future ocean drilling in this region.