共查询到20条相似文献，搜索用时 281 毫秒
1.
大巴山城口弧形断裂带右旋走滑构造特征及其意义 总被引：1，自引：0，他引：1
大巴山弧形构造带是几何学上对称平顶型、内部形迹削截的弧凸结构带,区域走向总体呈北西向延伸,其主边界城口断裂由北向南发生偏转（由近南北向→北西向→近东西向）,内部构造形迹与边界断裂呈明显削截和交切关系,弧形带凸顶方向与构造带南西向逆冲推覆极性一致。基于野外构造解析和15个样品的显微构造分析,对城口弧形断裂带右旋逆冲走滑构造特征和变形-变质特点及其沿走向的变化进行研究。宏观上,城口断裂带体现出早期近东西走向线理和平行于主断裂带弧形展布的后期线理两期世代和序列性,同时展现出强烈右旋走滑剪切变形特征,且走滑剪切变形强度由北西向南东减弱。微观构造上,断裂带构造岩普遍发生弱-中等强度变质,北段以中-高绿片岩相为主,右旋逆冲走滑剪切指向运动学标志体发育、变形强烈。断裂带南段以低绿片岩相为主,右旋走滑逆冲剪切指向运动学标志体相对稀疏、变形微弱。城口断裂带宏观与微观特征表明变质和（右旋走滑剪切）变形强度总体上由北西向南东逐渐减弱,呈非对称性。构造运动学上的非对称性和强烈右旋走滑剪切运动特征主要取决于印支期以来华南和华北板块汇聚过程中（尤其是燕山期）汉南能干性基底由南向北的强烈楔入作用。 相似文献
2.
内蒙古狼山地区断裂构造十分复杂，主要发育有南北、东西、北东和北西走向的断裂构造.从南北向断裂的几何形态、运动性质、构造应力场特征入手进行研究，结合野外实地调查与测量，运用极射赤平投影方法，求出构造应力场的主应力轴方位，进而对本区的构造演化进行了探讨.初步认为，研究区发育的近南北向断裂至少受到过两期构造应力场的作用，第一期是在晚二叠世，由于华北克拉通向北、西伯利亚板块向南活动而形成碰撞拼贴运动所产生的近南北向近水平挤压构造应力场，此时构造应力场的主应力轴σ1为北偏东10°左右，向北倾伏，倾伏角为15°~20°.在这一期构造应力场的作用下，狼山地区发育了一套破裂系统，它们分别表现为近东西走向的挤压构造带和逆断层、近北东走向的以左行为主的走滑断层、近北西走向的以右行为主的走滑断层以及近南北走向的张性断层.这些早期的断裂系统也制约着该区域后来的构造活动，第二期构造应力场是侏罗纪以来古太平洋板块向亚洲大陆俯冲而产生的.此构造应力场的主应力轴σ1为北西-南东向，倾伏向为150°左右，倾伏角为10°~20°.第二期构造应力场的作用，使早期南北向断裂由原来的张性破裂面转为左行走滑，早期东西向断裂转为右行走滑，早期北东向左行滑动面转为压性面和褶皱轴方向，而早期的北西向破裂面则转为张性破裂性质. 相似文献
3.
《吉林大学学报(地球科学版)》2015,(Z1)
<正>南图尔盖盆地位于哈萨克斯坦中部,是哈萨克斯坦的主要含油气盆地之一,主要目的层为侏罗系和白垩系。构造上,南图尔盖盆地位于Karatau走滑断裂的最北端,该盆地的构造特征、沉积特征、油气聚集均受到Karatau走滑断裂的影响。在南图尔盖盆地,Karatau走滑断裂是由两组不同规模的断裂构成的断裂系:一组走向为北西—南东向,走滑断层性质为右旋走滑;另一组走向为北东—南西向,起到构造调节作 相似文献
4.
根据地层层序特征 ,叠加在东秦岭造山带之上的泌阳凹陷伸展作用可以划分出 6个伸展作用幕。核二段沉积前泌阳凹陷以北东—南西向的伸展作用为主 ,构造变形受以正断层为主兼具左旋走滑分量的唐河—栗园断裂控制。核二段沉积期——廖庄组沉积末期构造应力场发生转变 ,以北西—南东向伸展作用为主 ,构造变形主要受以正断层为主兼具右旋走滑分量的泌阳—栗园断裂控制。断裂活动引起上盘构造变形 ,对先成构造进行改造。廖庄组沉积末期发生区域性的隆升作用 ,北西—南东向的伸展作用导致边界断裂上盘发生断块掀斜 ,地层遭受强烈剥蚀。核二段沉积以来尤其是廖庄组沉积末期 ,受北西—南东向不均匀伸展作用的影响 ,北西向走滑断层活动并影响盖层构造样式 相似文献
5.
大陆变形研究是大陆动力学的基本内容之一,对断裂构造及盆山演化进行研究是认识与了解大陆变形最直接有效的途径。中生代晚期—新生代,中国北方受到印度板块向北俯冲、太平洋板块向西运动与西伯利亚板块阻挡所导致的复杂构造动力系统的长期作用,地壳变形复杂,是研究大陆变形理想的天然实验室。本文在详细野外构造解析基础上,结合遥感与数字地貌技术、地震反射资料解释以及低温热年代学方法,通过对中国北方新生代断裂作用和山脉隆升历史研究,理清了断裂发育序次、断裂作用与构造应力场的对应关系,掌握了现今构造地貌格局东西差异的成因,并探讨了大陆变形的动力学机制。古新世—早始新世,中国北方普遍发育一组NNE向的断裂构造,该组断裂并非全区均匀发育,东部断裂规模较大,地貌特征明显,向西规模逐渐变小。NNE向断裂具有左行走滑的运动学特征,大致对应NW-SE向挤压应力场,推测NNE向左行走滑断裂的发育与新生代早期太平洋板块NNW向运动有关。NNE向断裂发育之后,东部渤海湾周边发育了NE向右行、NW向左行共轭走滑断裂,大致对应近EW向挤压应力场。西准噶尔地区发育了NE向左行、NW向右行走滑断裂,大致对应近NS向挤压应力场。东、西部的NE、NW向断裂都叠加在NNE向断裂之上,改造和破坏了早期NNE向断裂。本文推测东部后期断裂的发育与43~42 Ma太平洋板块运动由NNW转变为WNW向有关,而西部NE、NW向断裂发育与印度-欧亚大陆碰撞远程效应有关。随着印度板块持续北向运动并发生顺时针旋转,西部地区保持NNE向挤压应力场,发育了一系列NW、NNW向断裂。东部地区依然呈现近EW向挤压应力场。受到新生代以来各组断裂构造的影响,中国北方山脉和盆地呈现出线状与面状结合的网格状特征。磷灰石裂变径迹年龄统计显示,东部地区普遍经历了古新世—早始新世(66~42 Ma)的隆升-剥露,该期构造事件为现今东部地区构造地貌格局的形成奠定了基础。与东部地区不同,西部地区则存在8~6 Ma等时面,且8~6 Ma整体隆升-剥露为西部地区现今构造地貌格局的形成做出了主要的贡献。 相似文献
6.
济阳坳陷古生界潜山在经历了残丘山勘探阶段、多样性潜山勘探阶段之后,位于正向构造单元之间的中低位序复杂隐蔽潜山成为勘探主要方向。桩海地区东部紧邻郯庐断裂带,郯庐断裂带的多期构造运动对其产生深刻影响,古生界潜山构造样式非常复杂,并且由于埋藏深,前期地震资料精度低,构造特征认识不清,制约了勘探进展。该研究针对济阳坳陷桩海地区古生界复杂构造特征,运用高精度三维地震、钻井资料和区域应力场研究结果,探讨桩海地区古生界复杂构造特征及其形成机制。桩海地区古生界发育一套稳定的海相-海陆过渡相沉积岩系,自下而上依次发育寒武系、奥陶系、石炭系和二叠系。桩海地区古生界发育北西、南北、北东和东西4组走向的断裂,断层类型有正断层、逆断层和走滑断层。北西走向断裂5条,倾角较陡,平面上呈现正、逆相间分布的特点。南北走向断裂3条,剖面呈“花状”特征,为走滑断层。北东走向断裂为正断层,该组断层切割北西向断裂组。东西走向断裂主要是桩海地区潜山的南、北边界断层,该组断层切割北西走向断裂组。断层活动时期可划分为4期。第一期为印支期挤压形成的逆断层,断层贯穿古生界;第二期为晚侏罗至早白垩世构造反转形成的正断层,贯穿中生界和古生界;第三期为晚白垩世挤压形成的逆冲断层,贯穿中生界和古生界;第四期为始新世以来走滑和伸展形成的正断层,断层贯穿古生界、中生界、古近系和部分新近系。不同走向断层交汇切割,形成“棋盘格”式复杂构造。古生界顶面整体呈中部高、东西两侧低的背斜形态。自西向东可划分4排山。复杂的演化过程决定了不同潜山带保留层系和结构类型的差异性。对形成机制的研究结果表明:三叠纪末期—始新世,在郯庐断裂左旋→右旋“往返式”走滑变应力场控制下,桩海地区古生界经历了“挤压-拉张-挤压-走滑”4个演化阶段。三叠纪末期,在郯庐断裂左旋走滑运动下,桩海地区受到NE-SW向挤压、形成3条北西走向逆冲带;晚侏罗—早白垩世,桩海地区经历NW-SE向拉张,逆冲断层发生不均衡反转,形成北西向断层正、逆相间的特征,分割形成北西走向4排山雏形;晚白垩世,在郯庐左旋→右旋转换作用下,桩海地区受到NWW-SEE向挤压,经历二次挤压推覆,第二—四排山自东向西推覆,对古生界进行一次改造,基本奠定古生界构造格局;始新世,在郯庐断裂右旋走滑运动下,产生近南北向和北东向走滑断层及东西走向调节断层,切割早期北西向断裂组,同时在南、北边界断层伸展作用下,桩海地区发生南升北降翘倾运动,古生界构造样式定型,形成现今复杂的构造样式。构造演化控制桩海地区古生界潜山结构和成藏条件有所差异。自东向西地层逐渐减薄,西部地层剥蚀严重,第一排山仅保留寒武系,向东部的三排山保留的奥陶系逐渐增厚。第一排山发育寒武系断块圈闭,第二排山发育奥陶系—寒武系背斜圈闭,第三、四排山发育奥陶系—寒武系断块圈闭。从两侧向中间由断块山变为褶皱山、储集性变好,以第二排山奥陶系—寒武系逆冲褶皱山成藏最有利。 相似文献
7.
依据区域构造层次划分,采用构造筛分法,层层深入,层层筛分,确定发生于各个不同时代地层/岩层内的断裂活动的同期及叠加的应力场特征。综合所有的同期应力场特征及辅以叠加的应力场特征来验证,从而确定了一个连续的、完整的断裂活动的应力场演化序列;结合区域构造变形特征分析,阐明郯庐断裂带(安徽段)的构造演化。应力场分析显示:晚三叠-早侏罗世应力场为北北西—南南东或近南北向挤压,属古特提斯构造域,断裂发生同造山走滑;早白垩世早期,应力场为北西—南东向挤压,断裂发生左行走滑运动,中国东部处于西环太平洋构造域;早白垩世晚期—古新世(始新世),区域发生北西—南东向伸展作用,断裂处于伸展断陷作用阶段;新生代,受区域上近东西向的挤压作用影响,断裂发生挤压逆冲兼右行走滑作用。 相似文献
8.
南海西南部西纳土纳盆地中部走滑构造带分段性及对油气控制作用 总被引：1，自引：0，他引：1
为了研究南海西南部印度尼西亚纳土纳群岛西侧西纳土纳盆地走滑构造特征及对油气的控制作用,对研究区三维地震资料进行了精细分析,并结合切片和剖面特征对走滑构造进行了刻画。研究表明盆地中部中新世晚期发育北西向右旋走滑构造,由南东向北西,构造特征存在明显差异,根据其平面、剖面特征及活动强度分为东段、中段和西段。东段平面上为平直的、贯通的主干走滑断裂和雁列断层组,剖面上为花状构造;中段平面上为S型贯通的主干走滑断裂和雁列断层组,剖面上为花状构造;而西段平面上为雁列构造,没有贯通的主干走滑断裂,剖面上主要为断阶组合。推测走滑构造的分段性受走滑强度、断层几何形态和盖层厚度的影响,并对圈闭形成和油气运移、聚集具有明显的控制作用。 相似文献
9.
笔者对苏南东部及上海地区的北西向断层作了系统的野外观察,并对断裂带内构造岩作了详细地研究;对北西向断层的力学性质、构造地质特征及地质意义作了初步探讨。现介绍如下,如有不当,敬请指正。一、北西向断层的野外观察 (一)太湖大东岛,石炭系灰岩中发育了三条北西向压性断裂(图1、2),间隔40～50m。其中断层A走向北30°西,倾向北东,倾角75°;断裂带宽度为7m。断层B走向北35°西,倾向南西,倾角70°;断裂带宽度为8m。断裂C走向北35°西,断面近直立;断裂 相似文献
10.
琼东南盆地新生代发育机制的模拟研究 总被引：5，自引：0，他引：5
琼东南盆地是南海西北陆缘上一个北东走向的伸展裂陷带,向西与北西走向的莺歌海盆地相接,因此其构造演化包含了较多红河断裂走滑活动的信息。综合地质分析与物理模拟实验,我们发现琼东南盆地的发育既受控于南海北部陆缘的南东向—南南东向伸展作用,而且受到红河断裂左行走滑作用的控制和影响。其中,中央坳陷带主要受控于南东至南南东向的伸展作用;南部坳陷带的发育主要受控于琼东南盆地的伸展及其沿北北西向边界断裂右行走滑作用的构造叠加;而北部坳陷带的发育主要受控于北西向断裂左行走滑作用。红河断裂左行走滑作用可能开始于晚始新世,晚于琼东南盆地的伸展裂陷作用,且早期走滑速率应小于琼东南盆地的伸展速率,早渐新世(T70)以后红河断裂左行走滑速率大于琼东南盆地伸展速率,导致琼盆西段的褶皱反转,以及一组北西—北北西走向张剪断裂的发育。 相似文献
11.
S. Viswanathan K. Surya Prakash Rao B. Mahabaleswar 《Journal of the Geological Society of India》2013,82(6):621-627
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours. 相似文献
12.
E. M. Prasolov S. A. Sergeev B. V. Belyatsky E. S. Bogomolov K. A. Gruzdov I. N. Kapitonov R. Sh. Krymsky V. O. Khalenev 《Geochemistry International》2018,56(1):46-64
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others. 相似文献
13.
14.
奥地利安东帕有限公司 《岩矿测试》2009,28(3):306-306
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提 相似文献
15.
16.
Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance. 相似文献
17.
Alexander E. C. Broberg J. S. Kehren A. R. Graziani M. M. Turri W. L. 《Environmental Geology》1993,22(4):353-361
Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×106 1 of partially treated effluent and about 600 m3 of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes. 相似文献
18.
岩石密度和超高压岩石折返速率 总被引：1，自引：3，他引：1
在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。 相似文献
19.
20.
Mercury,arsenic, antimony,and selenium contents of sediment from the Kuskokwim River,Bethel, Alaska,USA 总被引：1，自引：0，他引：1
The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources. 相似文献