摘要:
渭河断陷南缘断裂带东起潼关,西至宝鸡,全长310公里,它的主边界断裂包括有华山山前断裂、秦岭北缘断裂。本文根据近年1:5万活动断裂地质填图最新详细资料研究了断裂的活动历史、分段性及其构造活动特征。华山山前断裂晚第四纪以来具有明显的新活动,沿断裂带及其两侧分布有最新断层崖、基岩裂缝、黄土裂缝、山体崩(滑)塌体等众多的地震形变和破坏遗迹,华山山前断裂应是1556年华县8级大地震的发震断层。#br#据华山山前断裂古地震剖面分析大地震重复间隔约2000-2500年,秦岭北缘断裂同样存在有基岩崩(滑)塌、裂缝、断层崖等古地震形变遗迹,由古地震剖面分析其大地震重复间隔约为2000-4000年之间。
Abstract:
The fault zone of the southern boundary of Weihe River begins east from Tongguan and terminates west at Baoji with a total length about 350Km.Its main boundary fractures in-clude the frontal fault zones of Huashan Mt.and Qinling Mt.The history of fault activity and the active characteristics are examined comprehensively according to the geological map(1:50,000).The outstanding new activity of the Huashan Mt.frontal fault zone is revealed.A-long this fault zone and its two sides are distributed the newest fault scarps, base rock frac-tures, loess crevices, landslide and mountain creep, and other deformation and damage relics due to earthquakes.Huashan Mt.frontal zone is most likely the genetic fault zone of 1556 Huaxian earthquake(M=8).#br#Based on the analysis of the two palaeoseismic profiles, it is supposed that the earth-quake recurrence interval is 2000-2500years for Huashan Mt.frontal fault zone, whereas 2000-4000 years for Qinling Mt.fault zone.