营潍断裂带走滑构造特征、演化及动力学机制

Strike-slip Tectonic Characteristics, Evolution and Dynamic Mechanism of Yingwei Fault Zone

摘要:

营潍断裂带位于渤海湾,是郯庐大断裂的北延段。由于受早期NW向断裂分割构造块的影响,营潍断裂带可分为走向和构造特征有显著差异的北、中、南三段,其走滑构造特征表现的非常明显,形成了一些特征性的伴生构造。断裂带的深部结构呈现出典型的平移断层性质,已切穿莫霍面乃至岩石圈,成为地幔热物质上涌或基性物质上涌的通道。通过综合分析区域板块构造演化、沉积盆地发育和岩浆活动特征,将营潍断裂发育演化历史归结为晚侏罗世-早白垩世(J3-K1)左行平移期、晚白垩世-始新世(K2-E2)伸展拉张期和渐新世以来(E3-Q)右行平移期三个阶段,并就其动力学机制进行了初步的讨论。

Abstract:

Yingwei fauh zone is the northern segment of famous Tanlu great fault system loeatied in Bohai sea area. Owing to be influenced by some early faults in NW direction, Yingwei fault zone can be divided into three segments which have apparently- strike-slipping tectonic characteristics and different accompanying tectonics. Typical strike-slip fault properties are presented in deep structure of Yingwei fault, where it cut deep into Moho and even the whole lithosphere, and become the surging passages for hot materials or basaltic materials from the mantle. By synthetically analyzing the structural evolution of regional plate tectonics, development of sediment basins and characteristics of magmatie activities, the evolution history of Yingwei fault is divided into three periods： the left-lateral strike-slipping period from late Jurassic to early Cretaceous （J3 - K1 ）, extensional period from late Cretaceous to early Eocene （ K2 - E2 ）, and right- lateral strike-slipping period from Oligoeene to now （ E3 - Q ） , and the dynamic mechanism for each period are discussed also.