| 项目编号: | 1646527
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| 项目名称: | Elasticity of clinopyroxene (Ca, Na) (Mg, Al, Fe) Si2O6 under Earth's upper mantle conditions |
| 作者: | Jin Zhang
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| 承担单位: | University of New Mexico
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| 批准年: | 2017
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| 开始日期: | 2017-02-15
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| 结束日期: | 2020-01-31
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| 资助金额: | 338618
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Earth Sciences
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| 英文关键词: | earth
; upper mantle
; single-crystal
; clinopyroxene
; single-crystal elasticity
; delamination
; eclogite
; experimental result
; interior
; mineral
; nature
; previous experimental study
; anisotropy
; anisotropic major mineral
; national laboratory
; major geological process
; deep earth
; crustal material
; state-of-the-art experimental facility
; single-crystal brillouin spectroscopy
; optical system
; p-t condition
; mantle composition
; relevant mineral
; high-symmetry material
; geodynamical modeling
; dynamic layer
; different chemical composition
; real earth p-t condition
; real earth
; destructive earthquake
; synchrotron single-crystal micro-diffraction
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| 英文摘要: | The Earth's upper mantle is one of the most dynamic layers of our planet and closely related to many tectonic processes adversely affecting human beings. For example, subduction and delamination, which are the two major geological processes of recycling crustal materials into the deep Earth, can result in seismic heterogeneities and anisotropies in the Earth's interior, as well as destructive Earthquakes and volcanisms on the Earth's surface. Therefore, understanding the nature and dynamics of the Earth's upper mantle is not only crucial for studying the mantle composition and convection but also relevant to society. Due to the difficulties of direct sampling, seismology provides by far the most accurate image of the Earth's upper mantle. Sound velocity and density measurements of relevant minerals are essential for understanding upper mantle seismic observations. Clinopyroxene, as a major phase of the Earth's upper mantle (10-30 vol%) and the dominating mineral of eclogite (about 60-70 vol%), is one of the most important yet least studied groups of minerals of the Earth's interior. Eclogite is widely believed to be the main driving force for subduction and delamination because of its high density. Thus direct density measurements of clinopyroxene at high pressure (P)-temperature (T) conditions are needed for calculating the buoyancy of eclogite in the Earth's interior. In addition, clinopyroxene is the most anisotropic major mineral in the Earth's upper mantle. It is also the only phase that contributes to any observed anisotropy of eclogite. Explanation of seismically observed upper mantle anisotropy requires knowledge of single-crystal elasticity of clinopyroxene at real Earth P-T conditions. Previous experimental studies have been limited mainly to high-symmetry materials, such as garnet, under P-T conditions far less than those expected in the Earth's interior. The purpose of this study is to measure the density and single-crystal elasticity of clinopyroxene in-situ, implement the optical system that is needed to complete the proposed experiments at University of New Mexico, apply the obtained experimental results to real Earth, and create unique opportunities for graduate and undergraduate students, especially underrepresented minority students, to participate in scientific research at the state-of-the-art experimental facilities both on campus and at national laboratories.
The investigators will use synchrotron single-crystal micro-diffraction and single-crystal Brillouin spectroscopy combined with CO2 laser heating or resistive heating methods to systematically investigate the thermoelastic properties (including density and single-crystal elasticity) of clinopyroxene with different chemical compositions up to 1800K and 18 GPa, covering the entire stability field in the Earth's upper mantle. The obtained experimental result will be used to assist seismic interpretation and geodynamical modeling, which will eventually contribute to our understanding of the origin and nature of the anisotropy and heterogeneity observed in the Earth's upper mantle. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/90530
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Jin Zhang. Elasticity of clinopyroxene (Ca, Na) (Mg, Al, Fe) Si2O6 under Earth's upper mantle conditions. 2017-01-01.
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