海原-六盘山地区位于现今青藏高原东北部,该地区活动构造的研究不仅可以为地震安全评价提供依据,也可以为第四纪青藏高原的扩展提供限定.在野外地质调查的基础上,运用光释光定年技术,限定研究区活动构造的活动时间.研究显示,海原-六盘山断裂和香山-天景山断裂在晚第四纪存在剧烈活动,产生了如角度不整合(夷平面)、褶皱和断层构造.这些结果表明,研究区应该作为地震安全评价的重点关注区域,同时也显示青藏高原东北部在晚第四纪存在持续的扩展. The Haiyuan-Liupanshan area is located in the northeastern part of the Qinghai-Tibet Plateau nowadays, and the research on the tectonics of the area can not only provide the basis for the seismic safety assessment, but also provide the limit for the extension of the Qinghai-Tibet Plateau in the Quaternary.Based on the field geological survey, The results show that the Haiyuan-Liupan fault and Xiangshan-Tianjingshan fault had violent activities in the late Quaternary, which resulted in the occurrence of angular disintegration such as angular unconformity, These results indicate that the study area should be the focus area for seismic safety assessment and also indicate that there is a continuous extension in northeastern Qinghai-Tibet Plateau in the late Quaternary.