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冀北超基性岩地质特征 总被引：1，自引：0，他引：1
冀北超基性岩带位于华北地台北缘，受崇礼－隆化深大断裂控制。该岩带从西往东可分为赤城、丰宁－滦平和承德－平泉三个超基性岩群。各岩群的形态、产状、岩石类型、矿物成份、化学成份各有特点，表现出一定的规律性。 相似文献
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城市大规模工程建设揭露了蕴含在土层中的丰富变形信息,调查发现合肥地区上更新统黏土中发育有数量众多的节理,节理成组产出,呈现不同交切、配套关系。通过对大量的调查数据进行统计分析,并绘制各调查点的节理玫瑰花图,将研究区内节理发育与断层分布逐一对比分析,结果显示合肥地区上更新统黏土中广泛发育的节理产状与场地附近的主要断层产状有关。走向玫瑰花图显示节理优势分布方位与场地附近主要断层走向近似一致;如果场地附近有多条断层交汇,土层中节理有以北西向较为优势的特征。 相似文献
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Chishan is located in Sixian County of Anhui Province, and the west branch fault of Tancheng-Lujiang fault zone passes through here. According to previous research, the Chishan segment of Tancheng-Lujiang fault zone has been obviously active since the Quaternary. Trenches excavated perpendicular to the Chishan segment for this study have revealed many prehistoric earthquake ruins-the multi-phase reverse faulting colluvial wedge, which is represented as the western brick-red sandstone of the late Cretaceous or maize gravel stratum of the mid Pleistocene of the hanging wall of the fault overlapping eastward the mid-late Pleistocene brown clay. In the base of the wedges, steep NW-dipping faults were found, and the steep fault planes turned upward to gently dipping collapse planes. As revealed by the trenches, the connection line of the breaking points strikes NNE in general. Heaving landforms are preserved at most parts of the tailing edge of the hanging wall where the fault passes through, and some EW-trending gullies were offset by right-lateral faulting. The two walls of several trenches have consistently shown that the collapse of traces have been pushed by a west-to-east force. Among them, Tc1~Tc4 show that the brick red limestone(K2)overthrust and collapsed on the yellow-brown clay containing ferro-manganese nodules (Q2-3P); Tc5 reveals that the yellowish-white gravel (Q2P) and the sandstone (K2) and overthrust and collapsed on the aforementioned clay. Reverse faulting colluvial wedges are found on both walls of each of the 8 trenches, but the number of wedges revealed in different trenches is different: there is 1 wedge, and 2 wedges in Tc1 and Tc3. 3 wedges in Tc2, Tc4 and Tc5, and in individual trenches, few wedges are revealed. This may be related to the trench’s location, depth and height of the remaining denudation. From the analysis of the trenches and the thermoluminescence dating results, we can preliminarily conclude that multiple large-scale reverse faulting stick events have taken place on the Chishan segment of the Tancheng-Lujiang fault zone during the mid-late Pleistocene, that is to say, many pre-historic strong earthquakes have occurred. 相似文献
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古遗址、古墓地发掘过程中的自然变形研究是反演或充实历史和史前变形历史记录的重要工作内容之一.近期我省地震部门会同省文物考古部门,对皖西霍山戴家院考古现场进行专题发掘调查,发现了与构造运动有关的地裂缝,其中充填有砂线、砂脉.初步研究显示包括两期变形,且均显示高速变形特征,代表两次地震事件.发生时代约相当于西周晚期和春秋中晚期,前者规模较大,含砂裂缝长轴方向平行于近侧的地震活动断裂方向.本次发现及初步分析填补了东部地区西周到春秋期自然变形事件研究空白. 相似文献
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选取1970年以来中国大陆东南地区5.0级以上、 华北地区5.5级以上、 西部地区7.0级以上地震作为研究对象, 并选择了8种物理意义明确、 独立性较强的地震学指标进行全时空的异常扫描, 通过改变采样时间域尺度、 空间域滑移及强度区间等样本条件, 分析对地震学指标时间进程计算结果的影响, 并讨论了空间扫描滑移方向相对于区域主应力方向的变化对参数扫描结果的影响。 结果表明, 空间参数的改变对扫描结果的影响最大, 并给出了不同震级地震学指标在扫描中影响最小的空间范围和时空扫描的最佳条件参数。 相似文献
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以华南、华北以及西部地区中强地震为例,选择了8种物理意义明确、独立性较强的地震学指标,以区域内断裂走向为参考,分别沿断裂走向进行平行、垂直、斜向滑移做空间扫描,以扫描曲线与震源区曲线的相关系数大小定量分析不同滑移方式扫描结果的差异,研究不同构造分区内断裂走向对地震学参数扫描结果的影响及变化规律。结果表明:不仅空间参数的改变对结果有影响,震源区内的断裂走向对地震学参数扫描结果也有一定影响。文中给出了不同震级地震学指标在扫描中影响最小的空间范围的最佳条件参数,同时也对不同断裂走向对参数扫描结果可能产生的影响进行了分析 相似文献
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