| 变斑晶包体形迹研究的几个问题 |
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| 引用本文： | 高坪仙.变斑晶包体形迹研究的几个问题[J].地质调查与研究,1997(4). |
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| 作者姓名： | 高坪仙 |
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| 作者单位： | 地矿部天津地质矿产研究所!天津３００１７０ |
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| 摘 要： | 变斑晶是联系变质与变形的重要媒介。变斑晶内的包体按几何形态可分为９大类。在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。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。在韧性剪切带中，由于存在变形分解作用，在岩石发生递进变形过程中，产于共轴或非共轴递进缩短带内的变斑晶也不发生旋转。利用未旋转斑晶中包体形迹可以确定早期面理的取向，寻找构造演化时间标志，确定变形变质关系及其演化史。如在大背坞地区，根据黄铁矿变斑晶的旋转演化，可以恢复韧性剪切带的成生演化历史。近十几年来由于计算机模拟的引人，使变斑晶微构造研究从定性步入定量阶段。
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| 关 键 词： | 变形分解作用 递进缩短 变斑晶旋转 螺旋形包体形迹 计算机模拟 |
SOME PROBLEMS IN THE STUDIES OF PORPHYROBLAST INCLUSION TRAILS |
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| Gao Pingxian.SOME PROBLEMS IN THE STUDIES OF PORPHYROBLAST INCLUSION TRAILS[J].Geological Survey and Research,1997(4). |
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| Authors: | Gao Pingxian |
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| Abstract: | Porphyroblast is an importent medium of relationship between deformation andmetamorphism. Nine types fo inclusion trails are classified according to two - dimensionalgeometrical Shape in Sections. Porphyroblasts in the progressively deformed metamorphic rocksnucleate and grow within the zone of progressive shortening by deformation partitioning. Exceptfor the spiralled garnets, most of the porphyroblasts do not rotate during the coaxial or non -coaxial progressive bulk inhomogeneous shortening. Deformation partitiming occurriflg in ductileshear zones gives rise to the growth of nonrotated porphyroblasts within the zone dominated bycoaxial or non - coaxial progressive shortening during progressive deformation. The inclusiontrails of porphyrolasts reflect reactivtion of external foliation. The inclusion trails in nonrotatedporphyroblasts can help determine the orientation of the early foliation, fold axes, and the timeCriteria of deformation history. In Dabeiwu area, based on the rotation of the porphyroblastsmost reconstruct the evolution of Dabeiwu ductile Shear zone. In the last decade, computermodelling employed in porphyroblastic microstructure research is a from qualitative analysis intoquantification. |
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| Keywords: | deformation partitioning progressive shortening porphyroblast rotationcomputer modelling spiral - shaped inclusion trails |
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