报告讲座 > 正文

徐惠芳: Plagioclase feldspars--modulated structures, phase transitions, and subsolidus phase diagram
发布日期:2019-05-27  字号:   【打印

报告时间:2019年5月29日(星期三)9:30

报告地点:西教学楼304会议室

  :Xu Huifang(徐惠芳) 教授

工作单位:威斯康辛大学地质与地球物理系

举办单位:资源与环境工程学院

报告人简介

徐惠芳教授,1984年南京大学地质系本科毕业,1987年在获南京大学硕士学位,1993 年在美国霍普金斯大学获博士学位。主要从事矿物结构、纳米地地质学研究。2010年被选为美国矿物学会Fellow。中国国家自然科学基金海外杰出青年基金获得者,中国科学院海外优秀学者。中科院贵阳地球化学研究所、广州地球化学研究所、地球环境研究所等单位兼职研究员,南京大学、中山大学兼职教授。在Science、Nature Geoscience、Earth and Planetary Science Letters、Geology、Geochimica et Cosmochimica、American Mineralogist、Environmental Science and Technology等国际一流杂志发表高水平学术论文100余篇。

报告简介

Plagioclase feldspar, a coupled solid solution between albite and anorthite, is the most abundant group of minerals in the Earth's crust. Their incommensurately modulated structures have puzzled geologists and crystallographers for decades since the phenomenon in a labradorite was reported in 1940. Solving the structure is a necessary step toward mapping the complex subsolidus phase relations of plagioclase solid solution. Determination of ordering state for an intermediate plagioclase requires structural information from satellite reflections, not just main reflections.

Modulation parameters like density modulation and variations of <T1o-O> bond distance are new parameters for quantifying the ordering state of intermediate plagioclase feldspars.The proposed phase relationship and T-T-t diagram for plagioclase feldspars are illustrated for explaining the relationship among different tructures and relative cooling rates of their host rocks.

(钱俊/文)  
编辑:徐小红
0