变质岩中变斑晶成核生长及旋转问题的述评  

NUCLEATION, GROWTH AND ROTATION OF POR-PHYROBLASTS IN METAMORPHIC ROCKS

作　　者：肖龙[1] 汪劲草[2] 

机构地区：[1]桂林冶金地质学院,541004 [2]中国有色金属工业总公司矿产地质研究院,桂林541004

出　　处：《地质科技情报》1993年第3期25-31,共7页Geological Science and Technology Information

摘　　要：发生递进变形的变质岩中,斑晶成核生长于变形分解作用的递进缩短带内,斑晶的大小受两侧递进剪切变形带的限制。除少数螺旋状石榴石外,产于共轴或非共轴递进不均匀缩短变形过程中的斑晶不发生旋转,斑晶内部包体形迹(Si)反映外部面理(Se)的再活化。利用未旋转斑晶中的包体形迹可以确定早期面理的取向,寻找构造演化的时间标志,确定褶皱轴迹等,本文给出了斑晶中包体形迹弯曲的成因模式图。Porphyroblasts in the progressively deformed metamorphic rocks nucleate and grow within the zone of progressive shortening by deformation partitioning. The size of por-phyroblasts is controlled by the progressive shearing zone on the two sides. Except for the spiralled garnets, most of the porphyroblasts do not rotate during the coaxial or noncoaxial progressive bulk inhomogeneous shortening. The inclusion trails of porphyroblasts reflect a re-activation of external foliation. The inclusion trails in nonrotated porplyroblasts can help determine the orientation of the old foliation, fold axes, and the time criteria of deformation history. A genetic model of curved inclusion trails in porpphyroblasts is given in the paper.

关 键 词：变形分解 变斑晶 成核生长 变质岩 

分 类 号：P588.3[天文地球—岩石学]