摘要
前人对软沉积物变形期次研究多数集中于触发变形的地震事件的周期,而对滑塌体内部软沉积物变形期次研究较少。山东灵山岛早白垩世复理石形成于残余盆地背景,且由于地震频发导致滑塌沉积广泛发育。滑塌沉积层中发育有丰富的软沉积物变形构造,如:同沉积滑塌褶皱、底模构造、剖面X形共轭逆断层、同沉积布丁构造、砂岩层断块及变形团块、微型地垒—地堑组合和叠瓦状倒转紧闭褶皱等。不同类型和不同部位的软沉积物变形构造显示出发育期次不同的特征。本文以灵山岛修船厂附近滑塌沉积层为例,分析软沉积物变形构造的变形机制,并将其发育期次大致分为滑塌前、滑塌中和滑塌后三个阶段。只有部分滑塌中的软沉积物变形构造具有滑塌指向意义,而滑塌前的变形构造不能用来判别滑塌体的搬运方向。
The Early Cretaceous flysch found in the Lingshan Island, Shandong Province, was formed in a remnant ocean basin. There are abundant slump deposit beds found in this flysch, indicating frequent strong earthquake events happened in the Early Cretaceous. There are different soft sediment deformation structures found in the slump beds, such as slump folds, sole casts, X-type conjugate thrust faults, synsedimentary boudinages, sand blocks and balls, mini hosts and grabens, imbricate reverse folds etc. Different types of soft sediment deformation structures show their different deformation stages compared to the slump deposition events. Taking the slump deposit outcrop section nearby the shipyard as an example, we have analyzed the mechanism of the soft sediment deformation structures, and classified these structures into three groups according to their formation period： the structures developed before slump, during the slump and after the slump. Some of the soft sediment deformation structures formed during the slump event can be used to identify the slump direction, whereas the structures developed before the slump, due to the long distance transportation of slump beds, cannot be used as the indicators of slump direction.
出处
《地质论评》
CAS
CSCD
北大核心
2013年第6期1060-1067,共8页
Geological Review
基金
现代古生物学和地层学国家重点实验室开放课题(编号0826060303)的成果
