【摘要】 作者通过野外实际调查及对重力、航磁等资料的分析认为,昌马—祁连断裂带中段（肃南香台子—寺大隆一带）全新世活动明显,表现为断错了全新世地层,同时还伴有山脊和水系的错断、断层崖、古地震崩塌和滑坡等。根据对堆积物C¹⁴年龄测定,距今4580年左右该段曾发生过一次7—7.5级地震。本文最后对该段地震危险性进行了讨论。更多还原

【Abstract】 Changma-Qilian fault is a major active fault zone in north-eastern margin of Qinghai-Tibet Plateau. Its median section （Xiangtaizi-Sidalong in Sunan County,Gansu Province）has had obvious activity in Holocene, and has been appearance of offsetting Holocene stratum along with offsetting ridge and stream system, the fault scarp and palaeoseismic collapses, landslides and so on.According to distribution and character of palaeoseismic collapses and landslides, C¹⁴ dating of correlative accumulation9 we estimate that at least one palaeoearthquake（M=7.0-7.5）occurred about 4680yr. B. P. Finally, the earthquake risk of this section is discussed.更多还原