Three Dimensional Evolution of Etch Pits on Crystal Olivine and Insights into Understanding Petrofabrics
详细信息
- 责任者：Wang Rong (Faculty of Land Resource Engineering ; Kunming University of Science and Technology ; Kunming 650093 ; China) ; Zhao Shanrong
- 刊名：Geological Journal of China Universities
- 出版年：2013
- 卷期：19(3)
- 关键词：橄榄石族 ; olivine group
- 页码：p.437-446
- 图表：8 illus., 3 tables, 21 refs.
- 分类号：0700
- issnNo：ISSN1006-7493
- isbnNo：CN32-1440/P
摘要
Chemical etching with 20% HF(HF+distilled water,volume rate) at room temperature was studied on seven sections of olivine crystals,i.e.,parallel twin(100),(010),(001),rhombic prism(110),(011),(101) and rhombic dipyramid(111) sections.AFM(Atomic Force Microscopy) and DIC(Differential Interference Contrast Microscope) methods were used to analyze these etched sections.With a fixed shape and angle,etch figures were different in each case,but all are elongated to [010] and shortened to [100].The face indices and the crystallographic orientation of a single crystal were only determined by the specific etch figures,also in rocks.Meanwhile,the etch figure symmetry displayed the point group mmm of olivine.Measured by a specific shape in DIC 200×,the reaction rate of the seven sections was v(010) >v(110) >v(100) >v(111) >v(101) >v(001) >v(011).Classified the etched random grain section indices identified by typical etch figure,the crystallographic preferred orientation of olivine grains in peridotites from Bixiling in Dabieshan areas,was defined as having strong maxima of [100],subnormal to the foliation,and strong maxima of [010],subparallel to the lineation.These observations may suggest that specific tectonic events affected the peridotites at the localities.