Abstract: Studies on the microstructure and matrix composition of fault-generated pseudotachy-lites,as well as their structural relationships in an ancient seismic source region,have revealed that deformation behaviour of the feldspar-bearing rocks transformed from ductility to rigidity prior to quartz-bearing rocks in a ductile shear zone at a crust depth rangeing from 15 to 10 km,along with crust uplifting and corresponding decreasing in temperature,would cause a strain instability somewhere and then the earthquake occurred.Varieties of the seismic fault-generated rocks and a dualistic deformation model have been discussed.

Key words: Seismic source substance, Pseudotachylite, Mylonite, Dabie Mountain

摘要： 古震源区地震断裂成因的假玄武玻璃显微构造、基质成分及其与区域构造演化关系的研究表明.随地壳抬升和相应的温度降低,在大约10～15km的深度上,长石质岩石先于石英质岩石从韧性转变为脆性性状,是导致韧性剪切带中局部应变不稳定和地震发生的主要原因。对地震断层岩石的多样性和地震成因的二相变形理论模型进行了讨论。

关键词: 震源实体, 假玄武玻璃, 糜棱岩, 大别山