摘要
渤海湾盆地辽河西部凹陷由于其丰富的油气资源和特殊的构造位置(郯庐断裂穿过此凹陷),其走滑构造的深入研究,对于揭示凹陷的构造演化和对油气成藏的控制作用以及郯庐断裂北段新生代的活动历史有重要意义。本文通过辽河西部凹陷三维地震资料系统的构造解析,并结合砂箱模拟实验,揭示了辽河西部凹陷存在多种与右行走滑相关的构造形迹,包括雁列正断层带、"梳状"构造、花状构造、"显形"和"隐伏"走滑断层等;确定了辽河西部凹陷的走滑活动开始于渐新世初期,活动强度开始时期(E3s1-2)较弱,逐渐加强,到渐新世末期(E3d1)达到最强,中新世有少量活动,上新世以来活动再次增强,活动比较显著,并持续到现今,推测整个郯庐断裂北段渐新世以来也有类似的演化历史;利用砂箱模拟实验确定在纯走滑拉分的条件下,约三分之二的走滑位移量可以转化为伸展量,并估算出辽河西部凹陷渐新世以来两侧基底累计的右行走滑位移量约为18km,其中渐新世(E3s1-2—E3d)、中新世(N1g)、和上新世以来(N2m—Q)的走滑位移量分别为10.5km、1.8km和5.7km,对应的平均走滑速度分别为0.71mm/a、0.10mm/a和1.11mm/a。
The western of Liaohe depression, which is Basin, with the Tanlu fault crossing through the rich in oil and gas resources and located in the Bohai Bay depression, offers a good opportunity to make an in-depth investigation of Its strike-slip structure, tectonic evolution and oil accumulation controlling, and action history of the northern section of the Tanlu fault during the Cenozoic. Through a systematic structural analysis of 3D seismic data in the westert Liaohe depression, combined with sand box modeling, this study reveals existence of a variety of structure signatures relevant to strike-slip in the depression, including echelon normal faults, ＂comb＂ structure, flower structure, and so on. The paper believes that the strikeslip of the depression initiated in the early Oligocene （E3 s^1-2）, gradually intensified and reached the culmination at the end of Oligocene （E3d^1）. It was less action in the Miocene and, since the Pliocene time, it has been gradually active up to now. It is speculated that the north section of Tanlu fault underwent similar evolution after Oligoeene. Sand box modeling test also indicated that under the condition of strike-slip pull, about two-thirds of the strike-slip displacement was turned into extensional displacement and estimation for cumulative right-lateral strike-slip displacement in the depression is about 18 km since Oligocene, in which the displacement is 10.5 km in the Oligocene （E3s^1-2-E3d）, 1.8 km in the Miocene （N1g） and 5.7 km in the the Pliocene epoch（N2m-Q）, with average strikeslip speeds of 0.71mm/a, 0.10 mm/a and 1.11mm/a respectively.
出处
《地质学报》
EI
CAS
CSCD
北大核心
2008年第8期1017-1026,共10页
Acta Geologica Sinica
基金
国家自然科学基金项目(编号40772086)
CNPC油气勘探超前共性科技项目(编号07-01C-01-04)资助成果
关键词
渤海湾盆地
郯庐断裂
走滑构造
构造演化
Bohai Bay Basin
Tanlu fault
strike-slip tectonics
tectonic evolution
