江西大背坞地区浅变质碎屑岩中韧性剪切带变形特征

浅变质碎屑岩中韧性剪切带的变形特征不同于长英质岩石中的韧性剪切带。以江西大背坞地区为例，阐述了在浅变质碎屑岩中鉴别韧性剪切带的标志，提出这种变形的构造岩的分类方案，同时对大背坞地区韧性剪切带进行应变测量和剪切位移估算，最后在岩石组构特征和综合分析基础上指出这种韧性变形机制是粒间滑动和粒内变形，其形成深度５～８ｋｍ、温度２５０～３５０℃、压力０１０～０２０ＧＰａ，是一种发育在地壳浅层次的低温低压条件下的韧性变形，其变形变质作用相当于低绿片岩相。

STUDY OF DUCTILE SHEAR ZONE DEVELOPING IN EPIMETAMORPHIC DETRITAL ROCKS, DABEIWU AREA, JIANGXI PROVINCE

The feature of ductile shear zone developing in epimetamorphic detrital rocks is different from that in felsic rocks. In this paper, the authors first elaborate on macroscopic and microscopic features of the ductile shear zone in epimetamorphic rocks of Dabeiwu area, and classify the tectonite in it. Then, the measurement results of the finite strain and the shear displacement of the Dabeiwu ductile shear zone are shown. On the basis of petrofabric characteristics and comprehensive analysis, the authors suggest that the deformation mechanism of the ductile shear zone is intergranular movement and intragranular deformation; it occurred in superzone of the crust with depth of 5～8km, temperature of 250～350℃, pressure of 0 10～0 20GPa; its deformation metamorphism belongs to low greenschist facies.