北祁连逆掩断裂带的缓倾角断层     

费琪  王燮培  曾晓明 《地球科学》1986,(3)

本文阐述了北祁连逆掩带中缓倾角断层的结构特征和地质意义。这些断层是本区走向北西西、断面南倾的区域逆冲断裂系的组成部分,断距大小不等,显示出一定规模的推覆构造型式。文中把本区和典型的逆掩推覆构造作了对比,并推断了这种缓倾角断层的演化模式。此项研究为进一步评价酒泉盆地以至河西走廊的含油远景提供了构造研究基础。  相似文献   

山东地区地震活动水平统计预测     

吴延河  盖殿广  周翠英  华爱军 《东北地震研究》2003,19(3):11-17

本文以山东三个分区为例，以y=a bx线性统计建模，进行逐年和分月地震活动水平拟合分析，给出了三个分区地震年、月应变能释放水平的经验关系，依此可以对相应区域的地震活动水平进行统计预测。使用山东地区地震资料进行内符和外推检验，结果表明这种方法不但简单，效果也较好，可以用于日常和年度及分月地震水平预测估计。  相似文献   

细观非均匀性对岩石破裂过程和微震序列类型影响的数值试验研究   总被引：15，自引：1，他引：15       下载免费PDF全文

焦明若  唐春安  张国民  石耀霖  侯万凯 《地球物理学报》2003,46(5):659-666

运用岩石破裂过程分析RFPA2D系统，研究了岩石介质细观非均匀性对宏观力学行为的影响和微震序列特征. 通过对不同均质度系数m=1.1，1.5，2，3，5的5个样本进行破裂过程的模拟，发现均质度不同会产生不同地震序列类型，主要有：前震-主震-余震型、主震型和震群型. 此外，对5种不同均质度系数的岩石样本破裂过程的模拟表明，岩石介质的非均匀性不仅对岩样宏观强度和宏观变形非线性行为有显著的影响，而且也显著地影响试样破裂模式. 随着均质度系数的提高，主破裂呈现脆断模式. 同时介质的细观结构随机性，也对试样宏观破裂模式产生重要影响.  相似文献   

C/B法城镇污水处理技术简介   总被引：1，自引：0，他引：1  

张生炎  扈胜禄  黄伟  王玉宾  孙伟 《矿产与地质》2003,17(1):78-81

目前我国城市污水处理普遍采用的工艺为普通活性污泥法、氧法沟法、SBR法及AB法等。这些工艺虽然运行稳定，达到可靠，但投资大、运行费用高。鉴于我国的经济发展水平与发达国家有较大的差距，污染治理的资金投入有限，提出必须研究适合我国国情的高效、低耗、低成本的城市污水处理技术。阐述了C/B法的C段和B段污水处理技术，指出由于该技术是化学强化处理技术与生物滤池技术的有机结合，综合了化学处理与生物处理技术的优点，具有可分阶段实施、投资省、运行费用低、占地少、有效去除磷、氨、氮等优点。  相似文献   

Quartz microstructures developed during non-steady state plastic flow at rapidly decaying stress and strain rate   总被引：7，自引：0，他引：7  

Claudia A. Trepmann  Bernhard Stckhert 《Journal of Structural Geology》2003,25(12):2035-2051

Synseismic loading to very high stresses (>0.5 GPa) and subsequent creep during stress relaxation in the uppermost plastosphere at temperatures of ca. 300–350 °C, near the lower tip of an inferred once seismically active crustal scale fault, was proposed based on peculiar microstructures identified in rocks exposed over >100 km² in the Sesia Zone, European Western Alps. Here we discuss the conspicuous and highly heterogeneous microstructural record of quartz in disseminated small-scale shear zones. Sub-basal deformation lamellae and arrays of elongate subgrains on the TEM-scale indicate an early stage of glide-controlled deformation at high stresses. Distributed brittle failure is indicated by healed microcracks. Very fine-grained recrystallised aggregates with a pronounced crystallographic preferred orientation reflect intense plastic flow by dislocation creep. Locally, a fine-grained foam microstructure indicates a final stage of static grain growth at low differential stress. For the previously inferred peak stresses of about 0.5 GPa and given temperatures, initial strain rates on the order of 10⁻¹⁰ s⁻¹ are predicted by available flow laws for dislocation creep of quartz. We emphasise the importance of short-term non-steady state deformation in the uppermost plastosphere underlying seismically active upper crust. The related heterogeneous record of quartz is governed by the local stress history at constant temperature.  相似文献   

Dynamic causes for the opening of the Baikal Rift Zone: a numerical modelling approach   总被引：1，自引：0，他引：1  

O. P. Polyansky   《Tectonophysics》2002,351(1-2)

Previous dynamic models of the Baikal Rift Zone (BRZ) are mostly two-dimensional on vertical plane. In this study, a numerical model of neotectonics in the region on map view was constructed using the adapted PLATES program. The present work is an attempt to test different mechanisms for opening Baikal Rift by comparing the modelled and observed stress and strain rate fields. The following rifting scenarios were tested: (1) pure northwest–southeast extension, (2) pure northeast–southwest compression, (3) oblique rift opening and (4) combined northwest–southeast extension and northeast–southwest compression. The models are calibrated using geologically and GPS-derived strain rates and stress-tensor determinations from fault-slip data and earthquake focal mechanisms. The most successful model requires a combination of NE–SW compression and orthogonal extension. The model results indicate that the present extensional regime in BRZ can be explained by combining the India plate indentation northward into Eurasia, east–west convergence between the North America and Eurasia plates and southeastward extrusion of the Amur plate in northeastern Asia. Predicted fault-slip rates for the best-fit model are consistent with the observed Holocene fault-slip rates in the Lake Baikal region. The generally accepted rotation of the Amur and Mongolia microplates are used as independent constraints for the choice of the best-fit model. These data correlate well with the predicted direction of rotation in our best model.  相似文献   

The influence of matrix rheology and vorticity on fabric development of populations of rigid objects during plane strain deformation     

Sandra Piazolo  P. D. Bons  C. W. Passchier   《Tectonophysics》2002,351(4)

The influence of vorticity and rheology of matrix material on the development of shape-preferred orientation (SPO) of populations of rigid objects was experimentally studied. Experiments in plane strain monoclinic flow were performed to model the fabric development of two populations of rectangular rigid objects with object aspect ratios (R_ob) 2 and 3. The density of the rigid object populations was 14% of the total area. Objects were dispersed in a Newtonian and a non-Newtonian, power law matrix material with a power law exponent n of 1.2. The kinematic vorticity number (W_n) of the plane strain monoclinic flow was 1, 0.8 and 0.6 with finite simple shear strain of 4.6, 3.0 and 0.9, respectively. In experiments with R_ob=3, the SPO is strongly influenced by W_n and the material properties of the matrix. Deformation of a power law matrix material and low W_n resulted in a stronger SPO than deformation of a linear viscous matrix and high W_n. Strain localization coupled with particle interaction plays a significant role in the development of a shape-preferred orientation. High strain simple shear zones separate trains of rigid objects that are surrounded by low strain zones with W_n lower than the bulk W_n. In fabrics involving populations of objects with R_ob=2, rheology of the matrix materials does not systematically influence the intensity of the SPO.  相似文献   

岩石试件端面效应的变形局部化数值模拟研究   总被引：10，自引：1，他引：10  

王学滨  潘一山  盛谦  丁秀丽 《工程地质学报》2002,10(3):233-236

试件端面效应直接影响试件内的应力分布、试件破坏形式和剪切带图案。采用FLAC - 3D模拟了端面效应对岩石试件剪切带图案、速度场和位移场的影响。试样端部的缚束作用较强时 ,仅在试样中部出现X形的剪切带 ;反之 ,在试样端部出现了倾斜的剪切带。压头刚性越大 ,剪切带倾角越大。块体具有整体平移的特性 ,剪切带边缘位移梯度却较大 ,反映了块体沿剪切带发生滑动的剪切破坏本质。数值模拟结果可在众多的试验结果中找到佐证。  相似文献   

变步长及角度子区稳健滤波方法的实现     

李沙园  孙长青  吴传芝 《安徽地质》2008,18(3):207-209

文章介绍了子区稳健滤波方法及作用。并建立了可变步长、角度滤波窗口的数学模型。利用该方法能得到较好的滤波结果。  相似文献   

A finite-difference algorithm for the transient electromagnetic response of a three-dimensional body   总被引：1，自引：0，他引：1  

Jopie I. Adhidjaja  Gerald W. Hohmann 《Geophysical Journal International》1989,98(2):233-242

  相似文献