摘要
利用野外露头和镜下薄片等资料、地质统计等方法,对山东省灵山岛老虎嘴剖面和船厂滑塌剖面软沉积物变形构造分布特征和形成期次进行了研究。船厂剖面发育滑塌褶皱、负载构造、阶梯断层、布丁构造、球—枕构造等典型的软沉积物变形构造;老虎嘴剖面发育层内褶皱、微阶梯断层、层内角砾岩等。根据形成时间、发育部位和形态特征,将船厂剖面变形划分为滑塌前变形和滑塌中变形,滑塌前变形又可以细分滑塌体下部变形和滑塌体内部变形。滑塌褶皱具有多级别、多尺度的特点;以厚岩层组成的滑塌褶皱为主,尺寸为米级;岩层内部纹层形成的次级褶皱为辅,尺寸为毫米级。滑塌过程中岩层不同部位应力不同,伴生其他变形构造,如拉张形成的布丁构造和挤压形成剪切褶皱等。滑塌前已经形成的负载构造等在滑塌过程中保持原来形态,不因地层变形而变形。这些古地震触发形成的软沉积变形构造证明灵山岛在早白垩世古地震活动频繁。
To analyze the distribution characteristics and formation stages of soft-sediment deforma- tion structures in slump folds in Lingshan Island, field outcrops, thin sections, geological statistics and some other methods was utilized to do comprehensive research on Laohuzui section and Chuanchang sec- tion. Giant slump folds, load structures, ladder faults, boudinages, ball-pillow structures and other de- formation structures developed on the Chuanchang section. And intrafolial folds, micro-ladder faults and intra-formational breccias, distributed on Laohazui section. According to the forming time, development position and morphological characteristics, deformations on the Chuanchang section were classified into pre-slump deformations and syn-slump deformations, and the pre-slump deformations were subdivided into infra-slump fold deformations and intra-slump fold deformations. Slump folds showed multi-order and multi-scale. The main slump folds were composed of thick layers of turbidite in meter-scale. The seconda- ry slump folds were composed of laminaes in milimeter-scale. There were different stresses in the different parts of rocks in the slumping process, with some other deformation structures concomitant, such as bou- dins formed by tensile stress and shear folds formed by extrusion stress. Load structures formed before the slump kept the original shapes in the slumping process, and didn＇t deform in the following rock deforma- tion process. The study on soft-sediment deformation structures of Lingshan Island proved that the palaeo- earthquake activities were frequent in the Early Cretaceous.
出处
《古地理学报》
CAS
CSCD
北大核心
2013年第5期717-728,共12页
Journal of Palaeogeography：Chinese Edition
基金
国家自然科学基金项目(编号:40872095
41272123)资助
关键词
山东省
灵山岛
早白垩世
滑塌褶皱
软沉积物变形
古地震
Shandong Province, Lingshan Island, Early Cretaceous, slump folds, soft-sedimentdeformation structures, palaeoearthquake
