【摘要】 利用莱州湾凹陷及其围区现有的地震、钻井等勘探资料,通过地层展布特点分析、构造恢复、单井埋藏史-沉降史分析等手段,对凹陷的新生代构造演化进行了详细研究。对地层与构造的研究分析发现,新生代存在两期构造应力场变革对莱州湾凹陷的形成演化起到至关重要的作用,即沙三期前后应力场转换(40Ma左右)与古近纪、新近纪之间的应力场转换(20Ma左右),其中前者与郯庐断裂由左旋转为右旋这一事件相耦合,而可能与之具有一定内在联系。对于盆地性质的分析认为,莱州湾凹陷并非典型的右旋走滑拉分盆地,而是受走滑作用影响的以伸展作用主控的裂谷盆地,其中沙三期之前可能为左旋走滑影响下的断陷盆地,而之后则为右旋走滑作用改造下的断陷-坳陷盆地。综合分析后,最终将凹陷在新生代的演化分为断陷期(孔店-沙四期—沙三期)、断拗期(沙二-沙一期—东营期)、坳陷期(东一期—馆陶期)、新构造活动影响期(明化镇期至今)4个阶段。更多还原

【Abstract】 The Cenozoic tectonic evolution of the Laizhouwan Sag were systematically analyzed using currently-available seismic and drilling data,distribution features,tectonic restoration,deposition and subsidence history,and etc.The sequence and tectonic analyses reveal that in the Cenozoic,there were at least two phases of tectonic stress field changes,which played vital role in the formation and evolution of the Layzhouwan Sag.One occurred during Sha3 period(about 40Ma)and the other between Paleogene and Neogene(about 20Ma).The former was coupled with another tectonic event,the Tan-Lu Fault’s slip reversal from left lateral to right lateral,and it implies that both of them may have some geodynamical relationship.Analysis of type of the basin indicates that the Laizhouwan Sag is not a typical right-lateral strike-slip pull-apart basin,but a rifted basin controlled mainly by the extensional regime affected by the strike-slip.It is likely that the basin was affected by the left-lateral strike-slip before Sha3 period,and then was reformed into rifted and depression basin under the influence of right-lateral strike-slip.Integrated study shows that evolution of the Laizhouwan Sag in Cenozoic can be divided into four stages:rifted stage(from Kongdian period to Sha3 period),rifting-depression stage(from Sha 2 period to Dongying period),post-rift depression stage(from Dong 1 period to Guantao period),and neotectonism-related post-rift depression stage(from Minghuazhen period to now).更多还原