高温韧性剪切带中一个长石变斑晶的出溶和压溶

来源期刊：中南大学学报(自然科学版)1989年第1期

论文作者：徐霭君 何绍勋

文章页码：1 - 8

关键词：剪切带； 压力； 溶解； 长石； 石英/出溶； 变斑晶

Key words：shear zone； pressure； solution； feldspar； quartz/exsolution； porphyroblast

摘    要：广东省阳春县永宁地区,沿四会-吴川剪切带出露的混合岩中,有一个长石变斑晶发育一组与变斑晶长轴约成45°夹角的石英细脉。石英细脉与变斑晶中长石条纹和聚片双晶的关系以及变斑晶中化学变化情况表明石英细脉不是沿长石剪切裂隙充填的而是压溶生成的,是长石变形同时发生变质反应和扩散的结果。根据压溶石英细脉推断的剪切带剪切指向,和沿剪切裂隙充填的石英脉所推断的结果相同。

Abstract: A feldspar porphyroblaste of migmatite in a shear zone at Yongning,Yang-chun county,Guangdong Province is studied in this paper.A set of quartz micro-veins cut through the porphyroclaste with an angle about 45° to the longer axis of porphyroclaste.The variability of chemical components in porphroclaste andthe geometic relationship among micro-veins of quartz and feldspar perthites and polysynthetic twins of plagioclase show that the quartz micro-veins as a result of metamorphism and diffusion during deformation of feldspar are formed not by filling in shear fractures,but by pressure-solution.The sense of shear zone is indicated by micro-veins of quartz which are similar to that indicated by filling type shear fracture.