排序方式： 共有7条查询结果，搜索用时 78 毫秒
1
1.
在野外地质调查、平衡剖面分析的基础上, 结合区域构造演化, 采用岩石声发射法对雪峰隆起西南缘的最大古应力进行了恢复, 并探讨了古应力大小与油气成藏破坏的关系。研究结果表明, 研究区共经历了5期不同强度的重要构造变革运动。在早古生代末期和印支期构造运动较弱, 声发射法的测量表明古应力值分别为13.3 MPa和24 MPa, 对应于麻江古油藏的主要成藏期。构造运动次数较多或者古应力值较大的时期, 主要对应于麻江古油藏储集层的发育期和油藏大规模破坏期。晚古生代末期构造活动次数较少, 但恢复地古应力值较大, 为92.6 MPa; 燕山期和喜马拉雅期经历了多期构造活动, 恢复地古应力值为23.3~74.4 MPa。 相似文献
2.
武夷山西南缘构造应力场演化及其与成矿的关系 总被引：2，自引：0，他引：2
武夷山西南缘及邻区地处华南特提斯与环太平洋构造域交接地带,自元古宙以来历经了多期次的构造演化,形成了相应的构造应力场。通过对主要古构造运动应力值大小的测定和3个主要构造演化阶段构造应力场数值模拟,得出古应力值自早到晚总体上有增大的趋势,到中生代古应力值强度大且持续时间较长。重要的成矿阶段主要对应区域拉张构造应力场。不同阶段构造应力场模拟结果表明,自前泥盆纪至燕山期,该区主构造线方向从EW—NEE向NE—NNE向转变,与主构造应力场的变化相对应。同时不同时代构造应力的分布为多金属矿产的形成创造了良好的成矿地质条件。 相似文献
3.
The Setouchi volcanic rocks include high-Mg andesites (HMAs) and garnet-bearing dacite–rhyolite, and are sporadically distributed along the Median Tectonic Line, Japan. New U–Pb zircon ages and geological and geochemical data are presented for those rocks in the Western Setouchi region (W-Setouchi). Previous studies referred to the altered andesite in the W-Setouchi as “pre-Setouchi volcanic rocks.” However, on the basis of the new U–Pb age (14.4 Ma ± 0.3 Ma) and geochemical characteristics, we redefine it as the Jikamuro Formation, part of the Setouchi volcanic rocks. Incompatible elements are more enriched in the Jikamuro Formation rocks than in the Setouchi HMAs. The characteristic element compositions may be explained by mixing of compositionally different magmas, including subducted sediment melts, plus a contribution from crustal contamination. A stress-inversion technique with Bingham distribution method was applied to the orientations of felsic and mafic dikes within the Setouchi volcanic rocks, and indicates paleo-stress conditions during the period of Setouchi volcanism in the W-Setouchi. The analysis reveals NNW-extensional stresses and a strike-slip stress. We infer that the former represents extensional conditions during the main period of volcanism and the latter represents a stress transition during the most recent period of volcanism (after 12 Ma). 相似文献
4.
Many equiaxial dome-like structures developed in the north segment of the Xuefengshan orocline, Central China are obviously inconcordant with the NE-trending linear structures in this area, which contain important records for understanding the structural framework and evolution of this belt. In this paper, taking one of the typical dome-like structures in the Xuefengshan orcline (e.g. Moping dome-like structure) as an example, based on its structural framework interpratatoin, superposed deformation analysis and paleo-stress fields reconstruction, we propose the Moping dome-like structure is composed of two populations of different-striking thrust-fold structures, ～E-trending and NE-striking structures, indicative of two-stages shortening, ～N- and NW-striking, respectively. Together with the geochronological analysis, we suggest the first stage of shortening occurred in Late Triassic to Early Jurassic, due to the Indosinian intercollisional orogeny of the Yangtze Block and the North China Block. The second occurred during Late Jurassic Early Cretaceous owing to Yanshanian intracontinental orogeny, leading to the intensive superposition of the NE-trending structures onto the ～E-trending structures, and the final ocurrence of the Moping dome. Thus, our study indicates the Xuefengshan arc-shape belt also experienced two-phase deformation, and resulted from the superposition of NE SW structures onto ～E-W structures in Late Jurassic Early Cretaceous, which could provide new structural evidence for probing the Mesozoic tectonic framework and evolution of the Xuefengshan orocline. 相似文献
5.
五莲拆离断层带中石英韧性变形明显,在野外主要表现为条带状、拔丝状,显微镜下主要表现为多晶石英条带,发育亚颗粒旋转重结晶和膨凸重结晶,剪切带经历了中低温条件下的变形,变形温度为300～450℃。利用分形方法对石英颗粒边界的研究表明,发生动态重结晶的石英颗粒边界具有统计学意义上的自相似性和明显的分形特征,亚颗粒旋转重结晶石英颗粒分维数介于1. 260～1. 319之间,均值1. 276;膨凸重结晶石英颗粒的分维数为1. 217～1. 297,均值为1. 256;根据石英粒径估算出亚颗粒旋转重结晶和膨凸重结晶作用变形阶段的古差异应力,分别为7. 84～21. 58MPa和18. 51～56. 65 MPa;基于分维值计算的应变速率计算公式,获得亚颗粒旋转与膨凸重结晶石英颗粒的应变速率分别为10-8. 4～10-7. 7s-1、10-10. 5～10-9. 7s-1;基于石英流变率计算,亚颗粒旋转重结晶的石英应变速率介于10-12. 88～10-11. 73s-1之间,膨凸重结晶的为10-13. 72～10-12. 46s-1。本地区韧性变形的应变速率大于一般性韧性剪切带应变速率,可能与拆离断层带的快速拆离伸展作用有关。 相似文献
6.
脆性岩储层裂缝定量预测的尝试 总被引：15，自引：0，他引：15
本文由四部分内容组成:(1)根据格里菲斯强度理论,讨论了脆性岩层在应力场(约定张为正)作用下,格里菲斯强度理论的一种破裂准则表示式及其在储层裂缝分析中的应用;(2)给出碳酸盐岩储层古应力场定量分析的三种数学力学模型和计算方法以及古裂缝定量预测可靠程度;(3)提出储层有效张应力概念及描述潜在张裂缝的方法;(4)提供某油田碳酸盐岩储层张裂缝的预测图及其以后通过钻井的检验。 相似文献
7.
陆内变形及其构造背景是地质学研究的热点之一。阿拉善地块东北缘的狼山地区中生代以来发育多期陆内变形,是研究陆内变形的理想地区。通过在狼山地区开展1∶5万构造地质填图,根据大量的野外观测、详细的测量和构造切割叠加关系,结合前人所做锆石年代学和低温热年代学工作,厘定出狼山地区自晚侏罗世以来发育6期陆内变形。断层面矢量数据反演显示不同期次构造变形形成于不同的构造应力场。先存构造和欧亚板块边缘自晚侏罗世以来不同方向的增生是控制狼山地区陆内变形的主要因素。晚侏罗世—晚白垩世,狼山地区的构造变形主要受古太平洋构造域的影响,进入新生代,狼山地区开始受到青藏高原构造演化的影响。 相似文献
1