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MARGINS Postdoctoral Fellowship: Deciphering the Role of Melt Segregation and Strain Partitioning in Rifting Continents

MARGINS 博士后奖学金：破译熔体分离和应变分配在裂谷大陆中的作用

基本信息

批准号：
0646696
负责人：
Benjamin Holtzman
金额：
$ 21.08万
依托单位：
Columbia University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2007
资助国家：
美国
起止时间：
2007-03-15 至 2010-02-28
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0646696&HistoricalAwards=false
关键词：
MARGINS Postdoctoral Fellowship Deciphering Role

项目摘要

The PI test the hypothesis that gradients in strain rate lead to gradients in degrees of melt segregation and thus gradients in seismic anisotropy. To do so he will use three approaches: 1) modeling of elastic properties, 2) application of model to data from Gulf of California, and 3) experiments to understand relationship between melt segregation, strain partitioning and effective viscosity.1. The effects of melt on isotropic velocities are fairly well studied, but anisotropic effects are less well understood. Seismic properties will be affected by aligned olivine crystals, oriented melt pockets at the grain scale, and meter-scale melt-rich layers. These effects are incorporated into a cumulative model of elastic properties, written in terms of the degree of melt segregation, in collaboration with J-M. Kendall (Univ. of Bristol) and Y. Takei (Univ. of Tokyo).2. Data from the seismic experiment in the Gulf of California conducted by J. Gaherty (LDEO) will be compared to data from the Gulf of California, to characterize the orientation and degree of melt segregation.3. The relationship between melt segregation, strain partitioning and effective viscosity will be constrained by deformation experiments on partially molten mantle rocks in torsional geometry, which allows for high-quality rheological data. This portion of the study will be performed in collaboration with D. Kohlstedt and a graduate student (Univ. of Minnesota). The potential broader impact of this project will be, primarily, to support the career of a young scientist. There will also be some training of a graduate student (with Kohlstedt) and increased international collaboration (Japan, Takei).

PI测试的假设，梯度应变速率导致梯度的熔体偏析程度，从而梯度地震各向异性。为此，他将使用三种方法：1）弹性特性建模，2）将模型应用于来自加州湾的数据，3）实验以了解熔体偏析，应变分配和有效粘度之间的关系。熔体对各向同性速度的影响已经得到了很好的研究，但各向异性的影响还没有得到很好的理解。地震属性将受到对齐的橄榄石晶体，在晶粒尺度上的定向熔体袋，和米级熔融富层。这些影响被纳入一个累积模型的弹性性能，写在熔融偏析的程度，与J-M。Kendall（布里斯托大学）和Y.武井（东京大学）。2.将由J. Gaherty（LDEO）在加州湾进行的地震实验的数据与来自加州湾的数据进行比较，以表征熔体分离的方向和程度。熔体偏析，应变分配和有效粘度之间的关系将受到部分熔融地幔岩石在扭转几何形状，这使得高质量的流变数据的变形实验。本部分研究将与D. Kohlstedt和一名研究生（明尼苏达大学）。该项目潜在的更广泛影响将主要是支持一名年轻科学家的职业生涯。还将对一名研究生进行一些培训（与Kohlstedt合作），并增加国际合作（日本，Takei）。