莱州湾海域郯庐断裂带活断层探测

利用浅地层剖面仪对郯庐断裂带莱州湾段进行了活断层探测，发现郯庐断裂带主干断裂在第四纪晚期以来具有明显的活动，继承了晚第三纪以来的主要构造活动特点，仍是这一区域的主导性构造. 西支KL3断裂由多条高角度正断裂组成，最新活动时代为晚更新世晚期至全新世早期，受到一系列错断晚更新世晚期沉积的北东或近东西向断裂的切割；东支龙口断裂由两段右阶斜列的次级断层组成，沿断裂带不但有明显的晚第四纪断错活动，而且还发育北北东向晚第四纪生长褶皱，表现出明显的晚更新世晚期至全新世活动特征. 在山东陆地区也发现了与龙口断裂相对应的安丘——莒县断裂，安丘段由一系列右阶斜列的次级断层组成. 从安丘向北至莱州湾凹陷，郯庐断裂带东支活断层构成了一条右旋单剪变形带，每一个次级活断层段相当于带内理论上次级压剪面，在第四纪晚期以来仍以右旋走滑活动为主要特征. 

ACTIVE FAULT SURVEY ON THE TANLU FAULT ZONE IN LAIZHOU BAY

Shallow-depth acoustic reflection profiling survey has been conducted on the Tanlu fault zone in Laizhou Bay. The result shows that the Tanlu fault zone is obviously active during the late Quaternary and it is still the dominating structure in this region. The Tanlu fault zone consists of two branches. The KL3 fault of the western branch is composed of several high angle normal faults which had been active during the period from the latest Pleistocene to early Holocene, it is dissected by a series of northeast or approximately eastwest trending faults. The Longkou fault of the eastern branch consists of two right-laterally stepped segments. Late Quaternary offsets and growth strata developed along the Tanlu fault zone verify that the fault zone retained active in the latest Pleistocene to the early Holocene. The Anqiu-Juxian fault that passes through the middle of Shandong and corresponds to the Longkou fault is composed of a series of right-laterally stepped segments. The active faults along the eastern branch of the Tanlu fault zone from the Laizhou bay to the north of Anqiu make up a dextral simple shear deformation zone which is characterized by right-lateral strike-slip movement with dip-slip component during the late Quaternary.