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1.
郯庐断裂带张八岭隆起段走滑运动与合肥盆地的沉积响应   总被引:19,自引:1,他引:19  
安徽北部的郯庐断裂带位于东侧的张八岭隆起与西侧的合肥盆地之间。断裂带内走滑糜棱岩、超糜棱岩及伴生岩浆岩的同位素测年,表明其走滑时间为早白垩世。一系列构造、沉积学的研究反映,郯庐断裂带在早白垩世的走滑运动,使合肥盆地东侧出现了北北东向延伸的张八岭走滑隆起,成为合肥盆地的沉积物源区。盆地东部相应出现了由下白垩统朱巷组充填、北北东向的大桥-肥东凹陷。该凹陷属于走滑挠曲盆地,其出现于张八岭走滑隆起西侧的走滑挠曲拗陷之中。  相似文献   

2.
谢皓  刘彩彩  张会平  詹艳  赵旭东 《岩石学报》2022,38(4):1107-1125
阿尔金断裂带是青藏高原自印度与欧亚大陆碰撞后向北扩展的前缘断裂,其新生代活动性对于研究青藏高原隆升与扩展过程和机制具有重要意义。近些年,运用热年代学、断裂几何学和运动学、沉积学、磁性地层学和地震学等方法对阿尔金断裂带的性质、组成结构、断裂活动时代、走滑断裂运动特征、走滑位移量和走滑速率等进行了细致的研究,而对阿尔金断裂带沿线受其控制的新生代沉积盆地的地层年代、沉积演化特征虽然也有一定研究,但往往仅限于单个盆地,缺乏对沿线盆地整体的对比认识,造成对阿尔金断裂带走滑起始时间及阿尔金山的隆升历史存在不同的认识。本文对近二十年来阿尔金断裂带沿线新生代沉积盆地的磁性地层年代与沉积相演化的研究进展进行综述,建立阿尔金断裂带沿线盆地新生代沉积序列和年代框架;辅助热年代学等资料,提出阿尔金断裂带的三阶段演化模型:始新世-中中新世,阿尔金断裂带以大幅度的走滑运动为主,同时伴随着阿尔金山小范围的隆升;中中新世开始,阿尔金山开始大规模的隆升,伴随着较少量的走滑运动;晚中新世以来,阿尔金断裂带构造活动加强。  相似文献   

3.
王剑  徐翔军  陈秀艳  李本才  王伟涛 《世界地质》2007,26(2):240-244,253
伊通地堑岔路河断陷南段,在地堑西北缘断层及二号断层(F2)的制约下,主要分为梁家构造带和新安堡凹陷两个二级构造单元。根据三维地震资料进行系统的构造解析认为,该区可划分为滚动背斜带、断块隆起带和走滑断陷带三个构造带。该区沉积相类型及其展布规律主要受控于东南缘断层、西北缘断层及F2断层的构造活动。受不同的构造-沉积特征制约,形成西北缘边界断层下的断层-岩性油气藏、中央隆起带断块式油气藏、F2断层控制的构造-岩性复合油气藏。  相似文献   

4.
秦岭南缘青川断裂新生代变形特征及其走滑运动学转换   总被引:2,自引:0,他引:2  
青川断裂作为秦岭构造带南部边界断层,新生代以来受到印度-欧亚大陆碰撞产生的远场效应,发生了强烈的走滑复活,调节了青藏高原隆升和向东扩展。本文基于错断地貌测量与断裂带脆性变形的野外调查,建立了该断裂新生代2期走滑运动历史,并讨论了走滑运动学转换的大地构造意义。沿断裂带河流水系偏移地貌分析发现,主要河流的Ⅳ级支流沿断裂发生一致的右旋偏移,指示断裂右旋位错量在200~800 m;河流阶地的右旋位错量在49~62 m。野外调查发现,青川断裂发育5~100 m宽的断裂破裂带,主要由断层泥、磨砾岩、断层透镜体等组成,S-C组构发育,磨砾石旋转定向排列。断裂破碎带运动学指向记录了青川断裂2期脆性走滑变形:早期为左旋走滑活动、晚期为右旋走滑活动。结合断裂带东端汉中盆地地层时代和秦岭山地隆升时代,我们推断晚期右旋走滑运动主要发生在上新世以来,调节了碧口地块的向东挤出;而早期左旋走滑运动则很可能是对古近纪晚期青藏高原隆升和扩展的响应。  相似文献   

5.
The Teisseyre-Tornquist Zone that separates the East European Craton from the Palaeozoic Platform forms one of the most fundamental lithospheric boundaries in Europe. Devonian to Cretaceous-Paleogene evolution of the SE segment of this zone was analyzed using high-quality seismic reflection data that provided detailed information regarding entire Palaeozoic and Mesozoic sedimentary cover, with particular focus on problems of Late Carboniferous and Late Cretaceous-Paleogene basin inversion and uplift. Two previously proposed models of development and inversion of the Devonian-Carboniferous Lublin Basin seem to only partly explain configuration of this sedimentary basin. A new model includes Late Devonian-Early Carboniferous reverse faulting within the cratonic area NE from the Kock fault zone, possibly first far-field effect of the Variscan orogeny. This was followed by Late Carboniferous inversion of the Lublin Basin. Inversion tectonics was associated with strike-slip movements along the Ursynów-Kazimierz fault zone, and thrusting along the Kock fault zone possibly triggered by deeper strike-slip movements. Late Carboniferous inversion-related deformations along the NE boundary of the Lublin Basin were associated with some degree of ductile (quasi-diapiric) deformation facilitated by thick series of Silurian shales. During Mesozoic extension and development of the Mid-Polish Trough major fault zones within the Lublin Basin remained mostly inactive, and subsidence centre moved to the SW, towards the Nowe Miasto-Zawichost fault zone and further to the SW into the present-day Holy Cross Mts. area. Late Cretaceous-Paleogene inversion of the Mid-Polish Trough and formation of the Mid-Polish Swell was associated with reactivation of inherited deeper fault zones, and included also some strike-slip faulting. The study area provides well-documented example of the foreland plate within which repeated basin inversion related to compressive/transpressive deformations was triggered by active orogenic processes at the plate margin (i.e. Variscan or Carpathian orogeny) and involved important strike-slip reactivation of crustal scale inherited fault zones belonging to the Teisseyre-Tornquist Zone.  相似文献   

6.
郯庐断裂中段管帅拉分盆地的确定及其构造意义   总被引:6,自引:7,他引:6       下载免费PDF全文
管帅盆地是郯庐断裂中段产出受左阶式走滑断裂控制的白垩纪盆地。该盆地长约30km,宽15km,具长宽比近于2:1的菱形构造格架。盆地内白垩纪王氏群的沉积时代为距今116~73Ma,总沉积厚度>3470m,沉积速率>80cm/103a;主体以冲积扇相—河流湖泊相沉积为主;同沉积构造发育,沉积相变剧烈,沉积中心侧向迁移特征明显,并与边界断裂的走滑效应具有一致性,具有拉分盆地典型的构造背景、构造格架及沉积特征。确定管帅盆地为郯庐断裂白垩纪走滑过程中形成的拉分盆地,并在此基础上分析了郯庐断裂左阶式走滑活动的构造特征及其对管帅拉分盆地的控制作用。  相似文献   

7.
玉树断裂带左旋走滑活动标志及其几何学 与运动学特征   总被引:2,自引:1,他引:1  
玉树断裂带位于甘孜-玉树断裂带北西段,是一条总体呈NWW向展布的左旋走滑活动断裂带.沿断裂带发育错断水系与冲沟、拉分盆地、地震地表破裂与断裂破碎带等一系列反映玉树断裂带左旋走滑活动的典型地质-地貌标志.在室内遥感解译的基础上,结合最新的野外实地调查成果,对沿玉树断裂带上反映其左旋走滑活动的地质-地貌标志进行了总结,并对断裂带的几何学与运动学特征进行了综合分析.结果表明,玉树断裂带总长约150km,总体走向120~130°,自西向东可划分为呈左阶雁列分布的陇蒙达-结隆段、结隆-结古段和结古-查那扣段3段.沿该断裂带发育的串珠状拉分断陷盆地规模的大小反映出玉树断裂带自西向东拉张效应逐渐减弱、挤压效应逐渐增强的特点.玉树2010年7.1级地震的宏观震中处于晚第四纪活动性最为显著的中段,而仪器震中恰好处于该断裂带的不连续部位,进一步证明雁列走滑活动断裂带上的不连续部位通常是强震活动的初始破裂区域.  相似文献   

8.
雅布赖盆地构造演化与油气聚集   总被引:1,自引:0,他引:1       下载免费PDF全文
雅布赖含油气盆地位于中国西部河西走廊地区北部,处于华北克拉通阿尔善地块中南部过渡带,属北祁连构造带,中生代为走滑拉分盆地,新生代为挤压冲断坳陷盆地。燕山早期,形成东西向雅布赖拉张断陷,主控断裂为北大山正断层,沉积中心位于盆地南部;燕山中期,碰撞造山作用致使盆地北部急剧抬升,北部中-下侏罗统地层遭受强烈剥蚀;燕山晚期,阿拉善地块及其北部地区处于伸展构造环境,雅布赖山前产生东西向正断层,急剧活动,快速沉降,形成了北东向展布的新的拉张断陷盆地。喜马拉雅期,在挤压走滑作用下,雅布赖盆地南部形成北西向南倾逆冲的推覆构造,致使北大山正断层发生错断瓦解,最终形成"东隆西坳,南断北超"的挤压坳陷构造格局。雅布赖盆地主体沉积凹陷具有较强分割性,沉降凹陷分布于南部,最大沉积岩厚度为5 400 m;凹陷内侏罗系最为发育,中侏罗统新河组、青土井组暗色泥岩、煤岩为烃源岩,砂岩为储集层,新河组泥岩互层作盖层,构成盆地内最主要的含油气组合。由于雅布赖盆地特定的早期深埋,晚期抬升破坏构造格局,造就侏罗系砂岩储层早期强烈压实致密,侏罗系煤系烃源岩成熟较晚,构造发育期与烃源岩排烃期不匹配,生成油气主要表现为近源成藏与层内滞留,形成源内自生自储,致密油应是主要勘探对象。  相似文献   

9.
小江断裂带第三纪走滑断陷盆地的充填层序特征   总被引:2,自引:0,他引:2  
小江断裂是滇中走滑断裂系中的一条主干断裂,沿断裂带发育了一系列带有明显走滑特征的新生代小型断陷盆地,第三纪含煤地层主要由冲积扇-湖泊、沼泽成因地层层序构成。本文在对多个断陷盆地的成因地层、充填序列、沉积体系域等剖析的基础上,讨论了走滑构造背景下断陷盆地的充填层序特征,并指出构造沉降、走滑作用和构造反转对盆地充填起作重要作用。  相似文献   

10.
楚雄复式盆地演化及形成的动力学机制   总被引:7,自引:2,他引:7       下载免费PDF全文
楚雄盆地处于中国云南省中部,位于扬子板块西南缘,南西界以红河断裂为界与哀牢山造山带相连,北西界为程海断裂,东边为绿汁江断裂。盆地基底包括结晶基底和褶皱基底双重结构。盆地内发育了中三叠世以后的沉积盖层,西部中三叠世和晚三叠世早、中期为海相沉积,晚期为海陆交互相和陆相沉积;盆地东部为陆相沉积。侏罗—白垩纪整个盆地为巨厚的陆相沉积。楚雄盆地的构造格架分为4个带:(1)哀牢山造山带;(2)褶皱逆冲带;(3)中部沉降带;(4)东部隆起带。盆地形成与演化分为六个阶段:(1)被动大陆边缘沉降阶段;(2)拉张热隆起边缘——裂谷盆地阶段;(3)沟-弧-盆系阶段;(4)残洋-周缘前陆盆地阶段;(5)走滑-拉张盆地阶段;(6)走滑-挤压-改造阶段。楚雄盆地的形成与演化体现了盆地动力学性质转化和复合,在多种动力系统作用下或经过多旋回构造阶段产生了复式盆地  相似文献   

11.
虎林盆地位于黑龙江省东部,是叠置在佳木斯地块之上的中、新生代断陷-坳陷盆地,其构造变形可以划分为3个构造演化阶段:早白垩世为NW-SE向伸展作用阶段,主要形成一系列各自独立的NE向箕状断陷群;晚白垩世为NW-SE向挤压作用阶段,使部分早期控陷正断层发生反转,形成反转构造,虎林盆地转化为具有多个沉降中心的NE向挤压坳陷盆地群;古近纪-第四纪为NNW-SSE向挤压作用阶段,虎林盆地的构造格局发生了重大变化,不仅使部分早期控陷正断层发生反转作用形成大型反转构造,而且在七虎林河凹陷与中央隆起之间形成NEE向大型逆冲断层(敦-密断裂)和断层传播褶皱,它们共同控制了盆地的形成和沉积作用,虎林盆地转化为具有1个中央隆起和南、北2个坳陷的NEE向挤压坳陷型盆地。东北地区自白垩纪以来始终处于活动大陆边缘的大地构造背景,包括虎林盆地在内的东北东部盆地群的形成与伊泽纳奇板块、太平洋板块向欧亚板块的俯冲作用有关。敦-密断裂带总体上呈NE向展布,具有左行走滑的性质,在靠近虎林盆地的北东段转变为NEE向展布,断层的性质也转变为逆冲断层,敦-密断裂带北东段的逆冲作用很可能与该断裂带的NE向左行走滑作用在NEE向的转换挤压有关。敦-密断裂带自古近纪始新世-渐新世虎林期开始活动,一直持续活动到第四纪。  相似文献   

12.
柴达木盆地东北部新近纪构造旋转及其意义   总被引:4,自引:1,他引:3  
青藏高原东北缘构造变形的研究是认识高原隆起过程、机制和印度—欧亚板块碰撞远程效应的重要途径。柴达木盆地是印度-欧亚板块碰撞后南北向挤压应力为动力背景的高原东北部内陆盆地,沉积物主要来自于周边山地,完整的保存了新生代以来高原隆升的详细记录。通过柴达木盆地东北部瑙格剖面精细古地磁及构造旋转研究发现,20.1~15.1Ma以及15.1~8.2Ma柴达木盆地分别发生了9.7°±7.4°和6.4°±4.4°的顺时针旋转,约8.2Ma后,柴达木盆地东北部瑙格地区发生了16°±7.5°的逆时针快速旋转。通过分析认为,前两次的顺时针构造旋转事件可能与阿尔金断裂的左旋走滑有关。而约82Ma以来的逆时针旋转事件属于柴达木盆地东北部瑙格地区的局部旋转,可能与温泉断裂的右旋走滑有关,说明青藏高原东北部在昆仑山、阿尔金山和祁连山三条巨型断裂系左旋相对运动的宏观控制下形成的NNW向温泉右旋走滑断裂开始走滑的年代为约8Ma。  相似文献   

13.
华北东部地区中生代盆地格局及演化过程探讨   总被引:29,自引:11,他引:18  
华北东部中生代盆地演化受控于欧亚构造域的板块挤压拼接和滨太平洋构造域"洋-陆"俯冲碰撞两大动力学背景,与兴蒙造山带、秦岭-大别造山带、太行山隆起及郯庐断裂带等陆内及周边造山带的形成、深大断裂发育演化以及深部动力等因素有着密切的联系。早-中三叠世华北地区基本继承了晚海西期以来的构造格局和沉积特点,地势北西高、东南低,为一南陡北缓、呈NWW向展布的大型内陆沉积盆地;晚三叠世扬子板块与华北板块剪刀式碰撞拼接,华北地区全面抬升,且西部抬升小,东部抬升幅度大,盆地范围向西部退缩,沉积范围缩小,东部地区地势较高,地貌复杂,以隆升剥蚀为主;早-中侏罗世华北东部处于由古亚洲构造域向滨太平洋构造域演化的过渡阶段,该时期太行山的形成将华北地区分割成东、西两个大盆,西部鄂尔多斯盆地依然为一个大型沉积盆地,东部渤海湾盆地区在早-中侏罗世的早期为一些小的山间沉积盆地群,主要表现为对印支期造成的大量NWW或近EW向逆冲断层及阔缓褶皱所产生的低洼地区的充填,晚期则表现为披覆式沉积;晚侏罗世-早白垩世太平洋板块活动取代了扬子板块、西伯利亚板块活动对华北地区构造演化的控制地位,中国东部进入大规模的裂陷或断陷盆地发育阶段,且出现了明显的分区性:在盐山-歧口-新港-兰考-聊城断裂系以东,由于受郯庐断裂带左旋走滑构造应力场的控制,主要发育NW或NWW向断陷盆地,而在该断裂系以西至太行山以东的地区,受左旋走滑影响较弱,主要发育NE和NNE向断陷盆地,在张家口-蓬莱走滑断裂带以北的下辽河坳陷区,盆地的长轴方向为NNE,属郯庐断裂带内部的走滑拉张盆地;晚白垩世郯庐断裂带以西的华北广大地区整体处于隆升剥蚀状态,仅在河南信阳盆地及冀中、临清、黄骅坳陷的少数低洼地区接受沉积,多以红色河湖相粗碎屑为主。研究华北东部中生代盆地演化对于该地区前第三系油气勘探具有指导意义。  相似文献   

14.
The Dead Sea Basin is a morphotectonic depression along the Dead Sea Transform. Its structure can be described as a deep rhomb-graben (pull-apart) flanked by two block-faulted marginal zones. We have studied the recent tectonic structure of the northwestern margin of the Dead Sea Basin in the area where the northern strike-slip master fault enters the basin and approaches the western marginal zone (Western Boundary Fault). For this purpose, we have analyzed 3.5-kHz seismic reflection profiles obtained from the northwestern corner of the Dead Sea. The seismic profiles give insight into the recent tectonic deformation of the northwestern margin of the Dead Sea Basin. A series of 11 seismic profiles are presented and described. Although several deformation features can be explained in terms of gravity tectonics, it is suggested that the occurrence of strike-slip in this part of the Dead Sea Basin is most likely. Seismic sections reveal a narrow zone of intensely deformed strata. This zone gradually merges into a zone marked by a newly discovered tectonic depression, the Qumran Basin. It is speculated that both structural zones originate from strike-slip along right-bending faults that splay-off from the Jordan Fault, the strike-slip master fault that delimits the active Dead Sea rhomb-graben on the west. Fault interaction between the strike-slip master fault and the normal faults bounding the transform valley seems the most plausible explanation for the origin of the right-bending splays. We suggest that the observed southward widening of the Dead Sea Basin possibly results from the successive formation of secondary right-bending splays to the north, as the active depocenter of the Dead Sea Basin migrates northward with time.  相似文献   

15.
塔里木盆地盆内震旦系特征   总被引:3,自引:1,他引:3  
结合前人对盆地周边露头研究成果,根据钻井和地震资料给出了盆地上、下震旦统的沉积体系分布。以阿满地区相对隆起为界,震旦系厚度总体上为东西厚、中间薄,沉积中心分布在盆地的东、西两端,并以东北角的库鲁克塔格山前地带沉积最厚,下震旦统达3400m,上震旦统也达2000m以上。早震旦世塔里木盆地主要发育了塔东和塔西两个沉积沉降凹陷,构成了塔东海洋冰川—浅海沉积体系区、塔西滨浅海沉积体系区、阿满海岸沉积体系区以及塔西南浅海—次深海沉积体系区,塔东和塔西两个沉积区以阿满海岸沉积区为界近乎对称分布。晚震旦世是在早震旦世沉积填平补齐的基础上的继承性沉积。  相似文献   

16.
The North Anatolian Fault (NAF) zone is 1500 km long, extending almost up to the Greek mainland in the west. It is a seismically active right-lateral strike-slip fault that accommodates the relative motion between the Turkish block and Black Sea plate. The Sea of Marmara lies along the western part of the NAF and shows evidence of subsidence. In this area pure strike-slip motion of the fault zone changes into extensional strike-slip movement that is responsible for the creation of the Sea of Marmara and the North Aegean basins. The northern half of the Sea of Marmara is interpreted as a large pull-apart basin. This basin is subdivided into three smaller basins separated by strike-slip fault segments of uplifted blocks NE-SW. Basinal areas are covered by horizontally layered sedimentary sequences. Uplifted blocks have undergone compressional stress. All the blocks are subsiding and are undergoing vertical motions and rotations relative to one another. The uplifted blocks exhibit positive Bouguer gravity anomalies. According to gravity interpretation, there is relative crustal thinning under the Sea of Marmara. The northern side of the Sea of Marmara is marked by a distinctive deep-rooted magnetic anomaly, which is dissected and shifted southward by strike-slip faulting. The southern shelf areas of the Sea of Marmara are dominated by short-wavelength magnetic anomalies of shallow origin.  相似文献   

17.
The results of magnetotelluric sounding are analyzed along the Korfovo-Astashikha-Novosergeevka profile 200 km long in the south of the Amur-Zeya sedimentary basin. The Korfovo-Astashikha and Korfovo-Novosergeevka profiles were sounded in the AMT and AMT + MTS regimes with a step between the observation points of 1 and 5 km, respectively. The shape of the MTS curves, their variations along the profiles, the shape of the polar plots of the main and additional impedance, and the parameters of the heterogeneity (N) and asymmetry (skew) are characterized. The dimensions of the geological medium is estimated and methods of the interpretation of the magnetotelluric data are chosen. The geoelectric sections are constructed for the depths of 3 and 150 km. The structure and electric properties of the sedimentary cover, the Earth’s crust, and the upper mantle are characterized. The thickness of the sedimentary cover in the grabens of the basin attains 1.5–1.7 km. Blocks with various resistivities were identified in the basement. Based on the contrasting changing of the electric resistances, the thickness of the Earth’s crust was determined as 38–40 km, which agrees with that established by the seismic data. The geoelectric structure of the upper mantle of the basin is relatively simple. A layer of elevated resistivity from the first hundreds up to a thousand Ohm · m was identified in the background of the low electric resistivity (20–30 Ohm · m) of the mantle in the depth range of 50–80 km. This layer is discrete and divided on the blocks by the zones of the decreased resistivity penetrating to the middle part of the Earth’s crust and coinciding with faults of various origins. The petroleum prospectives are estimated for the individual grabens of the basin.  相似文献   

18.
鹤庆–洱源断裂带是滇西北活动断裂系的重要组成部分,对其性质、特征和活动历史的研究可为区域地震活动评价和震害防御提供依据,也可为青藏高原东南缘构造变形特征、历史和方式提供基础数据。通过对鹤庆–洱源断裂带中段基岩山区的室内外调查和研究,结合光释光和14C 定年,初步查明该段断裂具有复杂的空间展布格局,由多条左旋走滑性质的分支断裂构成,它们共同吸收了断裂带在鹤庆盆地南端与洱源盆地北端之间的走滑分量;运动性质以左旋走滑为主,局部地段兼具正断或逆冲性质;剖面地层断错和覆盖关系表明该段断裂在晚更新世活动强烈,现有证据表明最新活动时代约为距今2万年。结合区域构造环境,作者认为鹤庆–洱源断裂带中段晚更新世以来的活动是对青藏高原强烈隆升的响应,其左旋走滑符合滇中次级块体顺时针转动模型,是块体旋转在角端的局部应变响应。  相似文献   

19.
塔里木盆地顺北地区发育大量走滑断裂带,并对油气的运聚成藏有重要控制作用。以顺北西部地区地震资料为基础,对顺北11号走滑断裂带的几何变形特征、活动性、活动期次及其形成机制等进行了分析。顺北11号走滑断裂带整体呈NNW走向延伸,具有垂向分层性和平面分段性。断裂带北段主体为压扭和张扭交互段,中段为两条次级断层控制的拉分地堑,南段由数条分支断层构成马尾状构造。顺北11号断裂带整体活动性由北向南减弱,运动学标志显示是一条右旋走滑断层。顺北11号断裂带主要经历了晚奥陶世和晚志留世-中泥盆世两期活动,部分地区的活动持续到石炭纪。顺北11号走滑断裂带的活动性和运动学特征与塔北地区NNW走向的走滑断裂体系比较相似,而不同于塔中地区的NE向左行走滑断裂体系。顺北11号走滑断裂带的形成主要受控于塔里木盆地北部天山洋多期俯冲挤压而产生的自北向南的挤压应力,断裂自北向南扩展延伸,类似于顺北5号走滑断裂带的北段。  相似文献   

20.
Field investigations reveal spatial variations in fault zone width along strike-slip active faults of the Arima–Takatsuki Tectonic Line (ATTL) and the Rokko–Awaji Fault Zone (RAFZ) of southwest Japan, which together form a left-stepping geometric pattern. The fault zones are composed of damage zones dominated by fractured host rocks, non-foliated and foliated cataclasites, and a fault core zone that consists of cataclastic rocks including fault gouge and fault breccia. The fault damage zones of the ATTL are characterized by subsidiary faults and fractures that are asymmetrically developed on each side of the main fault. The width of the damage zone varies along faults developed within granitic rocks of the ATTL and RAFZ, from ∼50 to ∼1000 m. In contrast, the width of the damage zone within rhyolitic tuff on the northwestern side of the ATTL varies from ∼30 to ∼100 m. The fault core zone is generally concentrated in a narrow zone of ∼0.5–∼5 m in width, consisting mainly of pulverized cataclastic rocks that lack the primary cohesion of the host rocks, including a narrow zone of fault gouge (<0.5 m) and fault-breccia zones either side of the fault. The present results indicate that spatial variations in the width of damage zone and the asymmetric distribution of damage zones across the studied strike-slip faults are mainly caused by local concentrations in compressive stress within an overstep area between left-stepping strike-slip faults of the ATTL and RAFZ. The findings demonstrate that fault zone structures and the spatial distribution in the width of damage zone are strongly affected by the geometric patterns of strike-slip faults.  相似文献   

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