山东省灵山岛下白垩统浊积岩中与滑塌作用相关的软沉积物变形构造

发布时间：2018-05-31 21:04

本文选题：滑塌褶皱 + 软沉积物变形构造　；参考：《地球科学》2017年10期

【摘要】：灵山岛上出露的软沉积物变形构造其成因具有多样性,而灯塔剖面底部滑塌层内的变形构造的触发因素尚不明确.结合野外观察和极射赤平投影方法,研究了滑塌层和内部变形构造的形成过程、触发机制和地质意义,结果表明:灯塔剖面主要由浊积岩沉积序列组成.滑塌层夹在未变形层之间,由地震触发形成,内部发育4个滑脱面,将滑塌层划分为5个变形单元,缩短率和变形程度各不相同.软沉积物变形构造主要为褶皱,形态特征表现为砂岩厚度在枢纽部位大大增加,也可见一些砂岩增厚和减薄现象,两者均是液化的砂岩在驱动力作用下的结果.滑塌过程中,滑塌层中的砂泥岩与海底沉积物之间的孔隙流体自由交换被切断,产生了暂时性的超压,导致了液化的发生.褶皱的轴线延伸方向为SSW-NNE,轴面倾斜方向主要为SEE(120°),指示古水流主要来自SEE方向,与浊积岩内底痕指示的古水流方向一致,说明斜坡沉积系统上发育的滑塌褶皱能够指示古水流方向.
[Abstract]:The deformation structures of soft sediments exposed on Lingshan Island are diverse in origin, while the triggering factors of deformation structures in the slide layer at the bottom of the lighthouse section are not clear. Combined with field observation and polar projection, the formation process, trigger mechanism and geological significance of the collapse layer and internal deformation structure are studied. The results show that the lighthouse section is mainly composed of turbidite sedimentary sequences. The sloughing layer is sandwiched between the undeformed layers, which is triggered by earthquake, and four slip planes are developed inside. The collapse layer is divided into five deformation units, and the shortening rate and deformation degree are different. The deformation structures of soft sediments are mainly folds, and the morphological characteristics are that the thickness of sandstone increases greatly in the junction, and some sandstone thickening and thinning can also be seen, both of which are the result of the driving force of liquefied sandstone. During the process of collapse, the free exchange of pore fluid between sand and mudstone in the sloughing layer and seabed sediment is cut off, resulting in temporary overpressure, which leads to liquefaction. The axis of fold is SSW-NNE.The direction of axis inclination is mainly SEE(120 掳, indicating that paleocurrent mainly comes from SEE direction, which is consistent with the direction of paleocurrent indicated by bottom marks in turbidite. It shows that the slip fold developed on the slope sedimentary system can indicate the direction of paleocurrent.
【作者单位】：中国石油大学地球科学与技术学院;
【基金】：国家自然科学基金项目(No.41322013) “深地资源勘查开采”重大科技创新工程项目(No.2017CXGC1608)
【分类号】：P512.2;P534.53

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