山东省灵山岛下白垩统青山群火山地震软沉积物变形构造特征及成因机制

发布时间：2018-10-29 18:13

【摘要】：近年来,针对山东省灵山岛地区软沉积物变形构造的研究呈现热潮,但研究层位主要集中于下白垩统莱阳群的浊积岩,对下白垩统青山群未见详述。利用野外露头与镜下薄片资料,详细描述了灵山岛地区下白垩统青山群的岩性特征、岩相组合、软沉积物变形构造类型与特征,指出研究区青山群软沉积物变形构造主要宿主岩层为陆相扇三角洲沉积,其沉积水体逐渐变浅,并伴随多次火山爆发。软沉积物变形构造类型主要有负载构造、球—枕构造、泄水构造、挤入构造、水塑性褶皱、塑性砂岩团块包卷构造、火山地震落石构造和"V"型地裂缝等,形成原因主要为火山爆发引起的古火山地震作用,成因机制主要分为地震波、火山碎屑物重力及惯性作用与瞬时差异气压效应3种,这与莱阳群浊积岩层位的软沉积物变形构造主要为滑塌与构造古地震机制不同。通过分析火山碎屑流堆积层位与软沉积物变形构造发育层位的关系,建立了青山群软沉积物变形构造的分布模式,即随着与火山口距离的变化,近源易见的脆性变形逐渐消失,中源以液化软沉积物变形与塑性变形为主体,远源呈现弱的液化软沉积物变形,且软沉积物变形构造的规模与距离呈负相关。
[Abstract]:In recent years, the study on deformation structures of soft sediments in Lingshan Island area of Shandong Province has shown an upsurge, but the study horizon is mainly concentrated on the turbidite of the Laiyang Group of Lower Cretaceous, and the Qingshan Group of Lower Cretaceous has not been described in detail. The lithologic characteristics, lithofacies assemblages, types and characteristics of deformation structures of soft sediments in Qingshan Group of Lower Cretaceous in Lingshan Island area are described in detail by using field outcrop and microscopic sheet data. It is pointed out that the main host rocks of the soft sediments in Qingshan Group are continental fan delta sediments, whose sedimentary water bodies are gradually shallower and accompanied by many volcanic eruptions. The main types of deformation structures of soft sediments include load structure, ball pillow structure, drainage structure, squeeze structure, water plastic fold, plastic sandstone mass enclosing structure, volcanic earthquake rock fall structure and "V" type ground fracture, etc. The main causes are paleovolcanic earthquakes caused by volcanic eruptions. The genetic mechanisms are mainly seismic waves, pyroclastic gravity and inertial effects and instantaneous differential pressure effects. This is different from the deformation structure of soft sediments in the turbidite strata of Laiyang Group, which is mainly composed of collapse and tectonic paleoearthquakes. Based on the analysis of the relationship between the accumulation of pyroclastic flow and the developmental horizon of deformation structure of soft sediment, the distribution model of deformation structure of soft sediment in Qingshan Group is established, that is, with the change of distance from crater to crater, the brittle deformation, which is easily seen near the source, gradually disappears. In the middle source, the deformation and plastic deformation of the liquefied soft sediment are the main body, the far source is weak deformation of the liquefied soft sediment, and the scale of the deformation structure of the soft sediment is negatively related to the distance.
【作者单位】：中国石油大学(华东)地球科学与技术学院;中国石油大学(华东)地球化学与岩石圈动力学开放实验室;米兰比可卡大学地球与环境科学系;山东黄河三角洲国家级自然保护区管理局;中海石油研究总院;
【基金】：国家自然科学基金项目(编号:41272123) 中央高校基本科研业务费专项资金项目(编号:15CX06011A)联合资助~~
【分类号】：P512.2;P534.53

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