• 责任者：Yang Yan (School of Earth Sciences and Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Yang Bo
• 刊名：Journal of Geomechanics
• 出版年：2013
• 卷期：19(3)
• 关键词：橄榄岩 ; peridotites ; 显微构造 ; ultrastructure ; 构造演化 ; structural evolution ; 祁连山 ; Qilian Mountains
• 页码：p.275-286
• 图表：10 illus., 1 table, 21 refs.
• 分类号：0300
• issnNo：ISSN1006-6616
• isbnNo：CN11-3672/P

     As a main component of upper mantle, peridotite affects the rheological behavior of the upper mantle. The microstructures contain records of tectonic events experienced during the development process of the specimen. Rheological parameters, such as temperature, confining pressure, factors of water and strain rate, are defined according to microtectonic observations, EBSD data and TEM results. Deformation mechanisms, deformation history of the Yushigou rock samples and geotectonic environment are summarized. Problems of petrogenesis and evolution history of the Yushigou peridotite body are finally concluded as： I , the evolution stage in the upper mantle, which is indicated by the A-type original fabric of olivine. The fabric of olivine lattice-preferred orientation （LPO） is determined by electron backscatter diffraction （EBSD） analysis. Our peridotite sample shows some upper mantle features, such as high temperature （ 〉 1200 ~C ） , low stress （ 〈 350 MPa）, low strain rate and low water content environmental conditions. II, the ductile-brittle deformation stage, showing D-type fabric which superimposed and transformed the A- type original fabric. Dynamic recovery is the main controlling factor for olivine deformation. Sub- grains, extinction bands and kink bands are generally observed by polarized-light microscopy, and are also shown as dislocation rows in the transmission electron microscopy （TEM） graphs. Brittle microcrack fabric including micro fractures with different dynamic nature is also analyzed as two groups of conjugate shear ruptures and another group of tension fractures. One same stage of paleostress field is shown by both microcrack and the ductile dynamic recovery phenomena.