| 项目编号: | 1530614
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| 项目名称: | Investigation on Modulated Structures and Subsolidus Phase Relations of Intermediate Plagioclase Feldspars Using Integrated Experiment and Simulation Methods |
| 作者: | Huifang Xu
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| 承担单位: | University of Wisconsin-Madison
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| 批准年: | 2014
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| 开始日期: | 2015-08-01
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| 结束日期: | 2018-07-31
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| 资助金额: | USD315690
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| 资助来源: | US-NSF
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| 项目类别: | Continuing 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: | e-plagioclase
; intermediate plagioclase feldspar
; e-plagioclase feldspar
; plagioclase feldspar
; subsolidus phase relation
; crystal structure
; structure
; study
; plagioclase binary system
; plagioclase feldpar
; 3d interactive mobile platform molecular simulation software tool
; investigator
; d structure
; single crystal x-ray diffraction method
; phase diagram modeling
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| 英文摘要: | Plagioclase feldspars are the most abundant minerals in the Earth's crust. They are major minerals in many commercial granite countertops and floor tiles. Precious stones like peristerite, moonstone, and iridescent labradorite are plagioclase feldspars too. The crystal structures and formation mechanisms of the plagioclase feldspars have been an enigma for decades beginning with their first discovery in 1940. The proposed study will help geologists to have quantitative understanding of their structures, stabilities, formation mechanisms, and evolution histories. The research results will be incorporated into both introductory level and graduate level courses taught by the investigators. The team of researchers is committed to the engagement of diverse graduate and undergraduate students in their research. The investigators and graduate students will continue outreach activities through the Geology Museum for K-12 community, mentoring high school students through summer reach opportunity, and developing open source software for learning, such as, AtomTouch, a 3D interactive mobile platform molecular simulation software tool for educational purposes. Because the studied incommensurate modulations in the intermediate plagioclase feldspars occur in a wide compositional range with continuous variation, the proposed study will also benefit the study of incommensurate modulations in other non-conventional (aperiodic) crystalline materials like intermetallic coumpounds with (3+1)D structures that may underlie new materials for future applications.
Recent aberration-corrected Z-contrast imaging results from the investigator's group reveal Ca-Na ordering and non-centrosymmetricity in both Na-rich and Ca-rich e-plagioclase feldspars. The multidisciplinary team will investigate the intermediate plagioclase feldspars that span the entire composition range (from ~An25 to ~An75) from different geological environments. Structural refinements of e-plagioclase feldspars will be carried out using new breakthroughs regarding non-centrosymmetricity and super space group characteristics to decipher the intricate nature of e-plagioclase feldspars. The proposed study includes the following 3 tasks: (1) Z-contrast imaging of intermediate plagioclase feldspars using an aberration-corrected scanning transmission electron microscope; (2) Crystal structure determination of e-plagioclase feldspars by single crystal X-ray diffraction method; and (3) Atomistic calculation of the subsolidus phase relations of the plagioclase binary system using density functional theory based phase diagram modeling. Both crystal structure and subsolidus phase relation of the intermediate plagioclase feldspars are very basic and important topics in mineralogy and petrology. Solving the problems of the mysterious incommensurately modulated structures and their subsolidus phase relations will provide improved understanding about behaviors of the plagioclase feldpars and their associations / intergrowths in metamorphic and igneous rocks that have experienced different evolution histories. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/93854
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Huifang Xu. Investigation on Modulated Structures and Subsolidus Phase Relations of Intermediate Plagioclase Feldspars Using Integrated Experiment and Simulation Methods. 2014-01-01.
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