牟平-即墨断裂带即墨段白垩纪古构造应力场特征

Characteristics of Cretacious Palaeotectonic Stress Field of Jimo Area in Muping-Jimo Fault Zone in Shandong Province

牟平-即墨断裂带是胶东地区一条重要的区域性断裂带。通过研究断裂带两盘不同构造层的共轭节理系、纵弯褶皱以及野外断层滑动矢量,对古构造应力场进行反演。结果表明,牟平-即墨断裂带即墨段白垩纪时期构造应力场具有以伸展为主,并与急剧的挤压作用交替进行的燕山旋回构造演化特征。断裂带经历了莱阳期、青山期的张性活动、各构造期末的左行压扭活动,以及王氏期的张性活动,最终以右行压扭性活动结束白垩纪的演化历史。伸展构造与岩石圈的减薄作用关系密切,而挤压作用则与周边板块,尤其是东部太平洋板块的运动方向和方式有着密切关系。

Muping-Jimo fault zone is an important regional tectonic zone.Through study on conjugate system,buckle fold and fault slip data,paleostress inversion has been carried out.1t is showed that palaeotectonic stress field in Jimo area in Muping-Jimo fault zone during the period of Cretacious has the characteristics of Yanshan Movement,that is priority to extension and alternate with mutation compression.Muping Jimo fault zone has experienced extension in Laiyang group and Qingshan group,lel^slip transpression at the end of every stage,and extension movement in Wangshi stage.Finally,it is finished by Cretacious evolvement history by right slip transpression.Extension has relationship with lithospheric thinning,but compression has vicinity with periferal plates,especially with the movement sense and means of Pacific Plate.