Collaborative Research: Geophysical Constraints on Mechanisms of Ocean Plateau Formation from Shatsky Rise, Northwest Pacific

该奖项是根据2009年美国复苏和再投资法案（公法111-2）资助的。破译巨大的火成岩省的起源是理解地幔动力学及其与陆地岩浆活动关系的关键因素。沙茨基海隆因其独特的构造背景而成为大洋中十几个大型海洋高原的重要研究对象。它是唯一一个在频繁的磁反转异常时期形成的巨大高原，显示了它与同时代扩张脊的关系。IODP第324号考察队目前还计划于2009年底在沙特基海隆的五个地点对沉积物和上部火成岩层进行取样，这可能提供重要的地面实况。研究所提出了一个有两个重点的地球物理合作项目：（1）通过OBS反射和折射实验限制地壳结构，（2）通过MCS剖面和水深测量和磁力数据的重新分析来描绘构造历史。一个新的地壳地震结构模型将在厚度和速度相关性的基础上约束地幔熔融的性质。MCS揭示的详细的上地壳结构将有助于重建Shatsky隆起的构造历史，该隆起似乎是一个巨大的火山，形成于三重连接点，然后通过海底扩张分裂。PI将综合这些地球物理研究的结果，以建立一个全面的构造框架，包括更好地估计喷发率，其时间变化，其与山脊运动学的关系，以及父母mantle.International与日本和俄罗斯科学家的合作，研究生和本科生的培训和航海经验是一些更广泛的影响的研究。还计划对在校学生进行宣传。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-2).Deciphering the origins of the giant large igneous provinces is a critical element for understanding mantle dynamics and its relation to terrestrial magmatism. Among a dozen or so large oceanic plateaus in the oceans Shatsky Rise is an important target because of its unique tectonic setting. It is the only giant plateau formed at a time of frequent magnetic reversal anomalies that show its relationship to coeval spreading ridges. IODP Expedition 324 is currently also scheduled to sample the sediments and upper igneous layers at five sites on Shatsky Rise in late 2009, which could provide important ground-truthing. The PIs propose a collaborative geophysical project with two foci: (1) constraining the crustal structure by an OBS reflection and refraction experiment, and (2) delineating the tectonic history by MCS profiling and reanalysis of bathymetry and magnetic data. A new model of crustal seismic structure will constrain the nature of mantle melting on the basis of correlation between thickness and velocity. The detailed upper crustal structure revealed by MCS will help to reconstruct the tectonic history of Shatsky Rise, which appears to be a huge volcano formed at a triple junction and then split apart by seafloor spreading. The PIs will synthesize the results of these geophysical studies to build a comprehensive tectonic framework, including better estimations of eruption rate, its temporal variation, its relation to ridge kinematics, and the coeval evolution of the parental mantle.International collaboration with the Japanese and Russian scientists and graduate and undergraduate students training and sea-going experience are some of the broader impacts of the study. Outreach to school students is also planned.