玉龙雪山周缘主要断裂的断层泥中石英碎砾表面SEM特征与丽江地震

Discussion on the Lijiang Earthquake and the SEM Characteristics of Surfaces of Quartz Gravels in the Gouge of Main Faults around the Yulong Snow Mountain

对玉龙雪山周缘 6条主要断裂的考察及活动年代研究结果表明 :其主要活动年代为晚更新世 ,全新世仍明显活动的断裂只有玉龙雪山东麓山前断裂 (F2 ) ,其它 5条断裂均不活动或活动较弱。 1996年丽江 7级地震的发震构造为玉龙雪山东麓山前断裂 (F2 ) ,其地震地表破裂面上、断层泥中石英碎砾约 5 %的颗粒表面被再改造 ;断裂最新地表破裂面上的构造岩物质 ,热释光 (TL)测年信号并未“归零”。

The investigation and study of the active periods of 6 main faults around the Yulong Snow Mountain are performed. The results show that the main active period of them was in the late Pleistocene. In Holcene, only the second fault(F 2),which is located on the east foot of the Yulong snow mountain, was obviously the active fault and other five faults were inactive or least active. The seismogenic structure of M7.0 Lijiang Earthquake is the second fault (F 2). The surfaces of 5 percentage quartz gravels in the disruption surface and in the gouge of the fault have been reformed. When determining the age of the substance of tectonite in the latest disruption surface of fault by thermoluminescence, the signal doesn't return to zero.