胶州——莱阳盆地白垩纪莱阳群中的震积岩及构造意义讨论

Seismites in the Laiyang Group in the Jiaozhou-Laiyang Basin,Shandong Province, and Their Tectonic Implications

通过对胶州-莱阳盆地沉积层的野外考察和岩心观察,系统分析了莱阳群的沉积特征及其变化规律,鉴别出一些较典型的震积岩类型;较详细描述了其中的粉砂质液化脉、震裂液化角砾岩、震褶岩和砂枕构造等地震液化特征。最后从盆地的区域地质背景出发,初步认为白垩纪早期胶州-莱阳盆地的形成与其南部苏鲁造山带的后期隆升同时,造成研究区总体处于伸展-裂解的构造环境之中。强烈的同沉积构造活动伴随频繁的地震发生,致使盆地内早期沉积的莱阳群以普遍发育震积岩为特征。

Based upon observations in the field and on drilling cores, this paper documents the sedimentary features and variations of the Cretaceous System in the Jiaozhou--Laiyang Basin, Shandong province. Several kinds of seismites, including vibrational liquefied sandstone veins, vibrational fractures, vibrational folds and sandypillow structure in the lower part of the Laiyang Group, are identified and described in detail. Taking the geological setting of the basin into account, the authors believe that the formation of the Jiaozhou--Laiyang Basin is coeval with the uplifting--extension of the Sulu ultrahigh-pressure terrane. The intensive synsedimentary tectonic activity has resulted in the widespread seismites in the Laiyang Group.