摘要
基于地震剖面解释、数字高程模型、历史地震、测年数据及钻孔等资料,分析了四川盆地熊坡背斜的构造特征、运动学特征及其成因机制。结果显示:(1)熊坡背斜与蒲江-新津断裂空间展布上具有较强的一致性,表现出断层传播褶皱模型,变形显著,缩短量为7.2 km,缩短率约为30%;(2)熊坡背斜隆起于(1.0±0.2)MaB.P.之后,且中更新世早期及晚更新世曾发生过强烈活动,使背斜两侧第四系厚度产生明显差异;(3)蒲江-新津断裂现今地震活动明显且小震频繁,曾有Ms=5.0~5.9的地震历史记录;(4)来自龙门山与扬子克拉通的挤压应力以及断层-滑脱作用是形成熊坡背斜的主要应力机制。熊坡背斜并非均匀应力下连续变形的产物,而是由于断裂活动时发生快速抬升而形成的。
Based on seismic section,DEM,historical earthquakes,dating and drilling data,this study ana-lyzed the structural features,kinematics characteristics and genetic mechanism of Xiongpo anticline in Sichuan basin.The results can be drawn as the following aspects:(1 )the space distribution of Xiongpo anticline is same with that of Pujiang-Xinjin fault zone,presenting a model of fault propagation fold and its shorten is 7.2 km with shorten rate about 30%;(2)Xiongpo anticline uplifted after (1.0 ±0.2)MaB.P.and it was very ac-tive in Early Pleistocene and Late Pleistocene,causing Quaternary-thickness difference between two sides of Xiongpo anticline;(3 )earthquakes especially small earthquakes happening in Pujiang-Xinjin fault zone oc-curred frequently and there has earthquakes history of Ms ranging from 5.0 to 5.9;(4 )the faulting-slipping and the crushing stress from Longmenshan to Yangtze craton are the main stress mechanism of Xiongpo anti-cline.It can be concluded that Xiongpo anticline formation is resulted from quickly uplifting when the fault is active rather than the product of uniform stress.
出处
《现代地质》
CAS
CSCD
北大核心
2014年第4期761-771,共11页
Geoscience
基金
国家自然科学基金项目(41372114
41340005
41172162
40972083)
国土资源部地质调查工作项目(1212011121268)
成都理工大学油气藏地质及开发工程国家重点实验室自主研究项目(SK-0801)
关键词
熊坡背斜
断层传播褶皱
成因机制
构造特征
前陆盆地
Xiongpo anticline fault propagation fold genetic mechanism structural feature foreland basin