走滑断层作用的相关构造

走滑断层的形成可以用纯剪和单剪这两种基力学机制和它们之间的过渡类型－压剪和张剪加以解释,其应力分布的局域性导致了形变特性的差异性。其相关构造类型,包括褶皱断层,断层,走滑盆地,走滑旋转构造,花状构造与走滑双重构造,等是走滑断层的主要研究对象和内容。     

印度-亚洲碰撞大地构造

印度-亚洲碰撞是新生代地球上最为壮观的重大地质事件.碰撞及碰撞以来,青藏高原的广大地域发生了与碰撞前截然不同的变形,地貌、环境及其深部结构都发生了深刻地变化.根据青藏高原形成、周缘造山带崛起以及大量物质侧向逃逸的基本格局,作者从大陆动力学视角出发,将"印度-亚洲碰撞大地构造" 与"前碰撞大地构造"区别开来进行研究,将印...     

新疆三塘湖盆地走滑构造特征与油气勘探

通过对钻井岩心资料系统观察以及地震资料的全面检查,证实新疆三塘湖盆地内存在走滑构造,表现为简单走滑(逆—平移)断层和正花状走滑断层两种基本形式。在中央拗陷带内走滑断层与边界主断层斜交并呈“雁列式”排列,表明走滑构造可能在边界断层发生大规模逆冲兼右行走滑时形成,其形成时期可能为喜山期。同时走滑构造对油气的生成、运移与聚集起着重要的控制作用。     

论走滑断层作用的几个主要问题

介绍了走滑断层作用研究前缘的若干主要方面。认为普遍使用走滑断层的术语外，在大陆上当断层性质不明时可使用平移断层。强调了单剪机制对大型走滑断层形成的作用，并评论了Ｘ破裂的纯剪理论。基于我国郯庐断裂带等的研究成果，提出走滑断层作用的若干新概念。指出剪曲（牵引）构造不同于雁列褶皱。认为中国地质学家从地质力学研究走滑断层的旋转构造已有卓绝的成就，只要同世界科学接轨，就会获得新的巨大生命力。文中描述了确定位移的方法，提出平移幅度与错距是两个不同的概念。强调了剪切热在大陆构造中的作用，提出走滑剪切带演化中剪切变形－断裂动热变质－重熔岩浆作用旋回。讨论了剪切成矿作用及已成矿体、矿带的走滑错移及变形。划分了三种基本走滑盆地类型及论证了大陆浅源走滑型地震机制。     

Evidence for early miocene wrench faulting in the Marlborough fault system,New Zealand: structural implications

In New Zealand, the Marlborough strike-slip faults link the Hikurangi subduction zone to the Alpine fault collision zone. Stratigraphic and structural analysis in the Marlborough region constrain the inception of the current strike-slip tectonics.Six major Neogene basins are investigated. Their infill is composed of marine and freshwater sediments up to 3 km thick; they are characterised by coarse facies derived from the basins bounding relief, high sedimentation rates and asymmetric geometries. Proposed factors that controlled the basins' generation are the initial geometry of the strike-slip faults and the progressive strike-slip motion. Two groups of basins are presented: the early Miocene (23 My) basins were generated under wrench tectonics above releasing-jogs between basement faults. The late Miocene (11 My) basins were initiated by halfgrabens tilted along straighter faults during a transtensive stage. Development of faults during Cretaceous to Oligocene times facilitated the following propagation of wrench tectonics. The Pliocene (5 My) to current increasing convergence has shortened the basins and distorted the Miocene array of faults. This study indicates that the Marlborough Fault System is an old feature that connected part of the Hikurangi margin to the Alpine fault since the subduction and collision initiation.     

Evidence for Early Miocene wrench faulting in the Marlborough Fault System,New Zealand: structural implications

Abstract

In New Zealand, the Marlborough strike-slip faults link the Hikurangi subduction zone to the Alpine fault collision zone. Stratigraphic and structural analysis in the Marlborough region constrain the inception of the current strike-slip tectonics.

Six major Neogene basins are investigated. Their infill is composed of marine and freshwater sediments up to 3 km thick; they are characterised by coarse facies derived from the basins bounding relief, high sedimentation rates and asymmetric geometries. Proposed factors that controlled the basins generation are the initial geometry of the strike-slip faults and the progressive strike-slip motion. Two groups of basins are presented: the early Miocene (23 My) basins were generated under wrench tectonics above releasing-jogs between basement faults. The late Miocene (11 My) basins were initiated by halfgrabens tilted along straighter faults during a transtensive stage. Development of faults during Cretaceous to Oligocene times facilitated the following propagation of wrench tectonics. The Pliocene (5 My) to current increasing convergence has shortened the basins and distorted the Miocene array of faults. This study indicates that the Marlborough Fault System is an old feature that connected part of the Hikurangi margin to the Alpine fault since the subduction and collision initiation. © Elsevier, Paris     

白乃庙金矿床控矿构造解析

白乃调金矿区的节理包括东西向剖面共轭剪切节理,北东－北西向平面共轭剪切节理,北北东向剖面共轭剪切节理。与之相应的断层有近东西向逆断层,北东向和北西向的平移断导以及北北东向的斜冲断层。此外,北东向断层的低序次构造亦呈北北东走向,但其性质为平移断层。东西向、北东和北西向断裂形成于南北向挤压构造应力场。它们控制了主要含金石英脉展布。其中,２６号主矿脉就位于北东向平移双断裂－白乃庙断裂的北北东向低序次平移     

Discussion of tectonic models for Cenozoic strike-slip fault-affected continental margins of mainland SE Asia

Understanding the roles of Cenozoic strike-slip faults in SE Asia observed in outcrop onshore, with their offshore continuation has produced a variety of structural models (particularly pull-apart vs. oblique extension, escape tectonics vs. slab-pull-driven extension) to explain their relationships to sedimentary basins. Key problems with interpreting the offshore significance of major strike-slip faults are: (1) reconciling conflicting palaeomagnetic data, (2) discriminating extensional, and oblique-extensional fault geometries from strike-slip geometries on 2D seismic reflection data, and (3) estimating strike-slip displacements from seismic reflection data.Focus on basic strike-slip fault geometries such as restraining vs. releasing bends, and strongly splaying geometries approach the gulfs of Thailand and Tonkin, suggest major strike-slip faults probably do not extend far offshore Splays covering areas 10,000’s km² in extent are characteristic of the southern portions of the Sagaing, Mae Ping, Three Pagodas and Ailao Shan-Red River faults, and are indicative of major faults dying out. The areas of the fault tips associated with faults of potentially 100 km+ displacement, scale appropriately with global examples of strike-slip faults on log–log displacement vs. tip area plots. The fault geometries in the Song Hong-Yinggehai Basin are inappropriate for a sinistral pull-apart geometry, and instead the southern fault strands of the Ailao Shan-Red River fault are interpreted to die out within the NW part of the Song Hong-Yinggehai Basin. Hence the fault zone does not transfer displacement onto the South China Seas spreading centre. The strike-slip faults are replaced by more extensional, oblique-extensional fault systems offshore to the south. The Sagaing Fault is also superimposed on an older Paleogene–Early Miocene oblique-extensional rift system. The Sagaing Fault geometry is complex, and one branch of the offshore fault zone transfers displacement onto the Pliocene-Recent Andaman spreading centre, and links with the West Andaman and related faults to form a very large pull-apart basin.     

Cenozoic noncoaxial transtension along the western shoulder of the Ross Sea, Antarctica, and the emplacement of McMurdo dyke arrays

Field data on Cenozoic faults and the McMurdo dyke arrays in the Reeves Glacier–Mawson Glacier area, Victoria Land, Antarctica, allow us to support noncoaxial transtensional tectonics along the N–S-trending western shoulder of the Ross Sea. Dyke injection within a crustal-scale right-lateral strike-slip shear zone is testified by magma filled, tension gash-like arrangements within some master fault zones, and by the left-stepping arrangements of dykes in the intrafault zones. The noncoaxiality of deformation is shown by the re-activation of many dyke walls as right-lateral strike-slip faults. This suggests an increase in the strike-slip component over time along the western shoulder of the Ross Sea. Our data support the relevance of transtensional to strike-slip tectonics for triggering melting and controlling the geometry and modes of magma emplacement.     

滇西北周城—清水断裂带晚新生代活动性初步研究

地表地质调查发现,位于滇西北菱形断块中南部的周城—清水断裂在上新世早期已经开始活动,而断裂强烈活动时期在中更新世,晚更新世以来活动性减弱。断裂运动方式以左旋走滑为主,兼有逆冲分量,并发生过从逆冲到正断的转换,全新世活动不明显。根据断裂断错的上新世昔格达组湖相沉积地质及河流地貌进行的初步分析,可以判断该断裂晚第四纪以来的垂直活动速率为0.1 mm/a左右,明显小于周城—清水断裂北侧川滇菱形块体向南东方向的运动速度(13~14 mm/a)。这表明周城—清水断裂对印度板块与欧亚板块碰撞所形成的次生构造———川滇菱形块体的侧向挤出的调节作用很有限。     

大陆构造变形与地震活动——以青藏高原为例

大陆内部构造变形和地震活动往往突显出复杂的、区域性的特征,很难用板块构造理论来解释。青藏高原是大陆构造变形的典型实例,具有不同构造变形的分区特征,不仅表现在物质组成、地形地貌和断裂组合等方面的不同,而且还表现出不同的地震活动特征。东昆仑断裂带以北的青藏高原北部地块,主要发育一系列挤压环境下的盆岭构造,表现为以连续变形为特征的上地壳挤压缩短变形;高原中北部巴颜喀拉地块,具有整体向东运动的特点,变形主要集中在其边缘,表现为刚性块体运动特征。在东部,由于稳定的四川盆地(扬子地块)的阻挡,位于龙日坝和龙门山断裂带之间相对坚硬的龙门山地区受到东西向强烈挤压,西部边界为伸展变形;在高原中央腹地羌塘地块西部,由于上地壳物质在向东挤出的驱动下不断变形,沿一系列小型正断层和走滑断层以伸展变形为主,表现为弥散型变形特征。相比之下,羌塘地块的东部向东-南东方向挤出,在大型走滑断层之间形成一个刚性块体;高原南部地块以东西向伸展的南北向裂谷系为主要变形特征,高原南缘以南北向挤压的大型逆冲断裂系为特征。历史地震和仪器记录的大地震(M≥8)只发生在高原东北和东南部的大型走滑带,以及东部和南部边缘的大型逆冲断裂上,沿后者更为频发。到目前为止,高原其他地区只发生了8级以下地震。青藏高原这种分区域的地壳变形形式和地震活动分布是大陆构造变形的重要特征。     

Kinematics of strike-slip faulting,builth Inlier,mid-Wales

Strike-slip faulting in the Builth Ordovician Inlier is demonstrated by large-scale maps of the Llanelwedd Quarries near Builth Wells, and by fault plane and slickenline data. In the main quarry steep NNW-striking strike-slip faults dominate the structure, together with significant strike-slip displacement on the W-dipping bedding surfaces and bedding-parallel faults. A zone of steep N-striking extensional dip-slip faults links two of the strike-slip strands and there is a weaker E-striking set of strike-slip faults. When the four fault sets are rotated so that the regional bedding is horizontal, three become vertical and one horizontal, probably their attitude during active life in late Ordovician to early Silurian time. They formed a linked fault system capable of accommodating three-dimensional bulk strain. The fault flats have the same kinematic role in a strike-slip system as lateral ramps or transfer faults in dip-slip systems.In the nearby Gelli Cadwgan quarry strike-slip faults are again dominant but strike E or ESE. This heterogeneity of fault pattern in the southern Builth Inlier resolves into more homogeneous domains with areas of 0.1 to 0.5 km² separated by E to NE-striking dextral strike-slip faults: Domainal structure, an important general feature of strike-slip tectonics, may be present on a variety of scales.     

大型走滑断裂对青藏高原地体构架的改造

青藏高原的大型走滑断裂有13条,已确定的大型韧性走滑断裂主要形成于3个时期:早古生代、印支期和新生代以来.印度/亚洲碰撞(60～50Ma)以来形成的大型韧性走滑构造位于青藏高原的南部,而且主要在喜马拉雅山链的东、西两侧,如西侧的喀喇昆仑和恰曼韧性右行走滑断裂,东侧的鲜水河-小江和哀牢山-红河韧性左行走滑断裂、崇山-澜沧江、嘉黎-高黎贡山和萨盖韧性右行走滑断裂等.主要的变形特征表现为早期具有地壳深部的韧性走滑剪切带性质,在后期抬升过程中,由韧性→韧脆性→脆性应变转化;而在青藏高原北部,表现为古韧性走滑剪切带的再活动,如阿尔金-康西瓦、东昆仑左行走滑断裂,以及新生的脆性断裂,如海源左行走滑断裂等.本文在青藏高原13条大型走滑断裂研究及综合研究的基础上,阐述不同时期的大型走滑断裂,以及它们在青藏高原地体拼合及碰撞造山中的作用,包括走滑断裂与走滑型褶皱造山、走滑断裂与挤压/转换型造山、走滑断裂与挤压盆-山体系、走滑断裂与地体相对位移和走滑断裂与地体的侧向挤出,以及走滑断裂与构造结的形成.     

造山带挤出构造

挤出构造模式已经从二维变形进入三维变形研究，在喜马拉雅造山带，高喜马拉雅结晶地体沿北倾的主中央逆冲断层和北倾 的绒布寺正断层，表现为相对刚性体之间的韧性体的楔状挤出。非连续介质大变形有限元数值模拟结果为这一模式提供了力学依据。在前人工作的基础上，提出了东阿尔卑斯三维管状挤出模式，将上部脆性层划分出北部左行平移带，南部右行平移带和中部挤出楔，中部韧性层在南阿尔卑斯和欧洲前陆碰撞过程中，既有垂向挤出，也有侧向挤出，在平行缩短方向的剖面上，由箱状背形隆起演化成逆－逆断层组合的楔状挤出，形成三角断面的管状，在垂直缩短方向的剖面上，中部韧性层呈不均匀流动，形成管状层流－韧性层中心为纯剪切，上部和侧部为简单剪切，在陕甘川邻接区，由于祁连山－北秦岭加里东喧向南的推挤和川西前陆的刚性阻挡，造成西秦岭和东松潘－甘孜复合造山体的三维滑脱挤出，以北西西向玛曲－略阳滑脱逆冲断裂和北东向青川一茂县滑脱逆冲断裂为界，将陕甘川邻接区的三维滑脱挤出复合造山体划分为西秦岭滑脱挤出带，摩天岭0若尔盖滑脱挤出楔和龙门山滑脱挤出逆冲椎覆带，以近南北向岷江滑脱逆冲断裂为界将滑脱挤出楔进一步划分成摩天岭滑脱挤出体和苦尔盖滑脱挤出体，除了不同构造单元的不均匀隆升外，摩天岭还表现出向西的侧向挤出。     

印度与欧亚板块碰撞以来东喜马拉雅构造结的演化

在野外填图,构造观察及前人研究的基础上,本文识别并描述了东喜马拉雅构造结中的推覆断裂、正断裂及走滑断裂、背斜(形)和向斜(形)等构造类型,讨论了这些构造位置及与印度板块挤入,印支地块旋转的关系,还探讨了东喜马拉雅构造结对印度板块持续向北推挤下的特殊应变调节方式。在印度大陆部分,东喜马拉雅构造结由3个向外逐渐变新的构造结组成,即北东向的南迦巴瓦峰复式背斜、北西向的桑复式向斜及北东向的阿萨母复式向斜。上述3个构造结是协调印度板块的挤入、喜马拉雅弧的扩展及印支地块的旋转的构造。在欧亚大陆内部的冈底斯岛弧,在派区及阿尼桥走滑断裂协调下,高喜马拉雅结晶岩的基底挤入冈底斯岛弧内部,在大拐弯顶端形成向上的挤出构造。在南迦巴瓦峰构造结的北西侧,由于掀斜式抬升及重力滑动,使得冈底斯盖层与结晶基底脱耦,上盘盖层沿东久向北西方向滑动。在南迦巴瓦峰构造结北东侧,由于印支地块的挤出和旋转,形成一系列的北西向走滑断裂,如实皆断裂、嘉黎-高黎贡断裂、澜沧江断裂及红河断裂等。     

郯庐断裂带莱州湾段新生代活动演变及其沉积-改造效应

本文根据对覆盖区地震、钻井等资料的精细解释和深入剖析,揭示在渤海莱州湾地区郯庐断裂带由东、西两条分支断裂带构成,二者又分别由两条主断层及多条次生断层和其间的断块组成。分支断裂带的两条主断层的间距因地而异,一般在5km左右;其结构构造和空间展布特征有别,西支表现为"两断夹一凸"的不对称地垒式,东支主要呈"花状"构造结构。通过古地质构造恢复和分期动态构造演化分析等综合研究,厘定了在新生代不同时期两条分支断裂带在该区不同单元的活动特点和构造-改造效应,进而总结了郯庐断裂带新生代主要阶段的构造属性及其演变。认为在古近纪早中期,研究区处于区域伸展沉降环境,郯庐断裂带对该区的沉积展布无明显控制作用;断裂带活动的明显控制沉积效应始于古近纪晚期,总体具伸展兼右行走滑属性,主要表现为切割和改造了研究区原近东西向展布的优势构造-沉积格局,同时控制了前期沉积地层的剥蚀强度及其分布范围和同期沉积。新近纪以来,郯庐断裂带两条分支断裂带的活动表现出差异显著的东强西弱;于第四纪,在东支断裂带出现正花状反转构造,可能与幕式走滑兼挤压活动有关。     

青藏高原东南部第四纪右旋剪切运动

通过对藏东南嘉黎断裂和滇西北断裂实地考察研究，表明青藏高原南部不存在统一的边界走滑断裂。嘉黎断裂的西段位于青藏高原南部，是一个南北挤压作用下的东西向伸展构造区，发育近南北向的地堑系，嘉黎断裂西段是这些地堑之间的转换断层，具有较高的右旋走滑速率。滇西北断裂与红河断裂构成川滇菱形块体的西南边界，该块体具有向东南逃逸和顺时针旋转运动。     

龙门山地震带的地质背景与汶川地震的地表破裂

龙门山位于青藏高原与扬子地台之间, 系由一系列大致平行的叠瓦状冲断带构成, 自西向东发育汶川茂汶断裂、映秀北川断裂和彭县灌县断裂,并将龙门山划分为3个构造地层带,分别为变形变质构造地层带（主要由志留系泥盆系浅变质岩和前寒武系杂岩构成）、变形变位构造地层带（主要由上古生界三叠系沉积岩构成）、变形构造地层带（主要由侏罗系至第三系红层和第四纪松散堆积构成）。 龙门山断裂带属地震危险区,3条主干断裂皆具备发生7级左右地震的能力,其中映秀北川断裂是引发地震的最主要断层,据对彭县灌县断裂青石坪探槽场地的研究结果表明,在该断裂带上最晚的一次强震发生在93040a.B.P.左右,据此,可以初步判定,这3条主干断裂的单条断裂上的强震复发间隔至少应在1000a左右,表明龙门山构造带及其内部断裂属于地震活动频度低但具有发生超强地震的潜在危险的特殊断裂,以逆冲-右行走滑为其主要运动方式。 汶川地震属于逆冲走滑型的地震,地表破裂分布于映秀北川断裂带和彭县灌县断裂带上。根据近南北向的断裂（小鱼洞断层、擂鼓断层和邓家坝断层）和地表断距可将映秀北川断层的地表破裂带划分为两个高值区和两个低值区,两个高值区分别位于南段的映秀-虹口一带和位于中北段的擂鼓北川县城邓家坝一带;两个低值区分别位于中南段的白水河茶坪一带和北段的北川黄家坝至平武石坎子一带,两个高值区分别与小鱼洞断层和擂鼓断层相关。根据保存于破裂面上的擦痕,可将该地震破裂过程划分为两个阶段,早期为逆冲作用,晚期为斜向走滑作用,其与地壳增厚构造模式和侧向挤出摸式在青藏高原东缘的推论具有不吻合性。鉴于龙门山的表层运动速率与深部构造运动速率具有不一致性,初步探讨了龙门山地区的地表过程与下地壳流之间的地质动力模型,认为下地壳物质在龙门山近垂向挤出和垂向运动,从而造成导致龙门山向东的逆冲运动、龙门山构造带抬升和汶川特大地震。在此基础上,根据汶川地震所引发的地质灾害,对地震灾后重建提出了的几点建议。     

Structure of Palaeogene sediments in east Ellesmere Island: Constraints on Eurekan tectonic evolution and implications for the Nares Strait problem

The “Nares Strait problem” represents a debate about the existence and magnitude of left-lateral movements along the proposed Wegener Fault within this seaway. Study of Palaeogene Eurekan tectonics at its shorelines could shed light on the kinematics of this fault. Palaeogene (Late Paleocene to Early Eocene) sediments are exposed at the northeastern coast of Ellesmere Island in the Judge Daly Promontory. They are preserved as elongate SW–NE striking fault-bounded basins cutting folded Early Paleozoic strata. The structures of the Palaeogene exposures are characterized by broad open synclines cut and displaced by steeply dipping strike-slip faults. Their fold axes strike NE–SW at an acute angle to the border faults indicating left-lateral transpression. Weak deformation in the interior of the outliers contrasts with intense shearing and fracturing adjacent to border faults. The degree of deformation of the Palaeogene strata varies markedly between the northwestern and southeastern border faults with the first being more intense. Structural geometry, orientation of subordinate folds and faults, the kinematics of faults, and fault-slip data suggest a multiple stage structural evolution during the Palaeogene Eurekan deformation: (1) The fault pattern on Judge Daly Promontory is result of left-lateral strike-slip faulting starting in Mid to Late Paleocene times. The Palaeogene Judge Daly basin formed in transtensional segments by pull-apart mechanism. Transpression during progressive strike-slip shearing gave rise to open folding of the Palaeogene deposits. (2) The faults were reactivated during SE-directed thrust tectonics in Mid Eocene times (chron 21). A strike-slip component during thrusting on the reactivated faults depends on the steepness of the fault segments and on their obliquity to the regional stress axes.Strike-slip displacement was partitioned to a number of sub-parallel faults on-shore and off-shore. Hence, large-scale lateral movements in the sum of 80–100 km or more could have been accommodated by a set of faults, each with displacements in the order of 10–30 km. The Wegener Fault as discrete plate boundary in Nares Strait is replaced by a bundle of faults located mainly onshore on the Judge Daly Promontory.     

走滑断裂叠置拉张区构造变形的物理模拟及启示

走滑断层的走滑量研究是构造分析过程中的关键,本文运用走滑断裂拉张叠置部位的构造物理模拟方法作为走滑量求取的手段,利用与自然界吻合程度较好的脆性-塑性双层模型对走滑拉张叠置部位进行模拟,发现叠置区主要发育与主边界断层呈80°~90°的横向断层(T断层)和呈顺时针45°的斜向断层(R剪切)两种类型的次级断层。通过改变实验中走滑断裂的叠置长度、横向间隔距离以及走滑量,计算不同实验中横向断层与斜向断层数量的比例并对实测数据进行拟合,结果显示:(1)叠置长度以及走滑量的增加或者横向间隔距离的减小,都会导致横向断层与斜向断层数量比的增加;(2)每组实验中的上述四个实测变量之间存在着特定的对数关系,通过对自然界中的走滑断裂拉张叠置区进行同比例缩小的构造物理模拟实验,获得四者之间的函数关系,从而可以确定走滑量。将构造物理模拟计算走滑量方法应用于渤海海域辽东湾地区郯庐断裂带,得到其新构造运动以来约发生了2.1 km的右旋走滑活动。