摘要
济阳坳陷由负反转盆地、右旋扭张盆地及主动裂谷三个原型叠加而成，并在中、新生代经历了四个演化阶段。三叠纪为板内造山作用阶段， 济阳坳陷曾为五条 Ｎ Ｗ向的以逆冲断层为主的压性构造带占据， 早—中侏罗世造山作用结束；晚侏罗世—早始新世为负反转盆地阶段，三叠纪 Ｎ Ｗ 向逆冲断层发生反向伸展；中始新世—渐新世为右旋扭张盆地阶段， Ｎ Ｅ、 Ｅ Ｎ Ｅ 向扭张断裂发育， 并进而成盆接受沉积， Ｎ Ｗ 向断裂反向伸展活动受到抑制而渐趋消亡；中新世—全新世为主动裂谷阶段，“拗陷运动”取代“断陷运动”。济阳坳陷构造演化的阶段特征表明了郯庐断裂中、新生代的剪切运动史， 即三叠纪右旋剪切， 晚侏罗世—早始新世左旋剪切， 中始新世—渐新世右旋剪切， 中新世—全新世作弱右旋压剪。
The Meso Cenozoic Jiyang depression is an assemblage of the negative inversion basin, dextral transtensional basin and active rift with four evolutionary phases. 1. The intraplate thrust orogenic phase (from the Triassic to Middle Jurassic): represented by the development of five NW striking compressive belts, which were mainly reverse faults. 2. The negative inversion phase (from the Late Jurassic to Early Eocene, i.e., 149～45Ma): the negative inversion of the previous reverse faults, leading to the development of SN striking high dip normal faulting. Therefore, the sediments mainly deposited in the NW trending half grabens. 3. The dextral transtensional phase (from the Late Eocene to Oligocens, i.e., 45～24.6Ma ): development of the NE striking dextral transtensional faults, the WNW trending sinistral transtensional fault, the secondary ENE striking dextral transtensional fault and the EW striking normal fault. These faults controlled the sedimentation in the basin and the previous faults became inactive. Consequently, the dextral transtensional basin overlapped the negative inversion basin. 4. The active rifting phase (from the Miocene to Holocene, i.e., 24.6Ma～present): the previous differential block faulting was replaced by the regional depression. The evolution of major faults in the Jiyang depression could be used to interpret the shear kinematics history of the Tan Lu fault zone in the Meso Cenozoic. The results of this study demonstrated that the Jiyang depression underwent dextral shear during the Triassic, sinistral shear from the Late Jurassic to the Early Eocene, dextral shear from the Middle Eocene to the Oligocene, and weak dextral transpression from the Miocene to the Holocene.
出处
《高校地质学报》
CAS
CSCD
1999年第3期275-282,共8页
Geological Journal of China Universities
关键词
济阳坳陷
负反转断裂
郯庐断裂
大地构造意义
Jiyang depression, negative inversion basin, dextral transtensional basin, Tan Lu fault
