Physical analog (centrifuge) model investigation of contrasting structural styles in the Salt Range and Potwar Plateau,northern Pakistan

We use scaled physical analog (centrifuge) modeling to investigate along- and across-strike structural variations in the Salt Range and Potwar Plateau of the Himalayan foreland fold-thrust belt of Pakistan. The models, composed of interlayered plasticine and silicone putty laminae, comprise four mechanical units representing the Neoproterozoic Salt Range Formation (basal detachment), Cambrian–Eocene carapace sequence, and Rawalpindi and Siwalik Groups (Neogene molasse), on a rigid base representing the Indian craton. Pre-cut ramps simulate basement faults with various structural geometries.A pre-existing north-dipping basement normal fault under the model foreland induces a frontal ramp and a prominent fault-bend-fold culmination, simulating the Salt Range. The ramp localizes displacement on a frontal thrust that occurs out-of-sequence with respect to other foreland folds and thrusts. With a frontal basement fault terminating to the east against a right-stepping, east-dipping lateral ramp, deformation propagates further south in the east; strata to the east of the lateral ramp are telescoped in ENE-trending detachment folds, fault-propagation folds and pop-up structures above a thick basal detachment (Salt Range Formation), in contrast to translated but less-deformed strata with E–W-trending Salt-Range structures to the west. The models are consistent with Salt Range–Potwar Plateau structural style contrasts being due to basement fault geometry and variation in detachment thickness.     

Three-dimensional Evolutionary Models of the Qiongxi Structures, Southwestern Sichuan Basin, China: Evidence from Seismic Interpretation and Geomorphology

Fold terminations are key features in the study of compressional fault-related folds. Such terminations could be due to loss of displacement on the thrust fault or/and forming a lateral or oblique ramp. Thus, high-quality seismic data would help unambiguously define which mechanism should be responsible for the termination of a given fault-related fold. The Qiongxi and Qiongxinan structures in the Sichuan Basin, China are examples of natural fault-propagation folds that possess a northern termination and a structural saddle between them. The folds/fault geometry and along-strike displacement variations are constrained by the industry 3-D seismic volume. We interpret that the plunge of the fold near the northern termination and the structural saddle are due to the loss of displacement along strike. The fault geometry associated with the northern termination changes from a flat-ramp at the crest of the Qiongxinan structure, where displacement is the greatest, to simply a ramp near the northern tip of the Qiongxi structure, without forming a lateral or oblique ramp. In this study, we also use the drainage pattern, embryonic structure preserved in the crest of the Qiongxinan structure and the assumption that displacement along a fault is proportional to the duration of thrusting to propose a model for the lateral propagation of the Qiongxinan and Qiongxi structures. Specifically, we suggest that the structure first initiated as an isolated fault ramp within brittle units. With increased shortening, the fault grows to link with lower detachments in weaker shale units to create a hybridized fault-propagation fold. Our model suggests a possible explanation for the lateral propagation history of the Qiongxinan and Qiongxi structures, and also provides an alternative approach to confirming the activity of the previous Pingluoba structure in the southwestern Sichuan Basin in the late Cenozoic.     

库车再生前陆盆地冲断构造楔特征

库车再生前陆盆地冲断构造楔由一系列向南运动的逆冲断层和相关褶皱组成。冲断楔的北部以断层转折褶皱、断层传播褶皱、双重逆冲构造为主。断层楔的前缘发育了很好的滑脱膝折背斜,全为盲断层控制,形成隐蔽式前锋。冲断层的就位从中新世开始,自北向南迁移,前锋的构造形成在第四纪。造成逆冲断层的地壳水平缩短作用速度在中新世较慢,平均为0．355mm/a,上新世中期达0．82mm/a,而到上新世晚期和第四纪速度增大了约一个数量级,达到1．29－3mm/a。     

断层相关褶皱的三维构造几何学分析:以川西三维地震工区为例

现有的断层相关褶皱理论均基于平衡剖面原理而建立的二维几何学模型。所谓的假三维模型则是通过一系列的二维剖面复合而成的,真正意义上的三维断层相关褶皱理论尚未确立,仍然处于探索阶段。本文采用Trishear 4.0和GoCad软件,分别构建一系列不同位移量的断层转折褶皱和三剪断层传播褶皱的二维正演剖面,将这些正演剖面按照一定的线性位移梯度平行排列,从而建立起断层转折褶皱和三剪断层传播褶皱的假三维理论模型并加以分析和讨论。进而选取川西南盆地中三维地震勘探所覆盖的邛西断层转折褶皱和盐井沟断层传播褶皱,作为真三维实际解释模型的两个实例。研究表明,邛西背斜是一个典型的剪切断层转折褶皱,盐井沟背斜是一个典型的三剪断层传播褶皱;断层相关褶皱的假三维理论模型与实际解释模型的对比分析,可以看出沿背斜走向的位移梯度是控制三维构造几何学特征的基本因素,然而自然界断层面几何学的复杂多变以及岩层力学性质的各向异性,是造成断层相关褶皱真三维理论模型难以建立的主要原因。     

Main Frontal thrust deformation and topographic growth of the Mohand Range,northwest Himalaya

The Main Frontal thrust (MFT) uplifts the Himalayan topographic front. Deciphering MFT deformation kinematics is crucial for understanding how the orogen accommodates continuing continental collision and assessing associated hazards. Here, we (a) detail newly discovered fault-zone exposures along the MFT at the Mohand Range front in northwestern India and (b) apply contemporary fault zone theory to show that the MFT is an emergent fault with a well-developed fault zone overlain by uplifted Quaternary gravels over a horizontal length of ∼700 m. Northward from the front, the fault zone grades from a central, gouge-dominated core to a hanging-wall, rock-dominated damage zone. We observed incohesive, non-foliated breccia, fault gouge, and brittle deformation microstructures within the fractured country rocks (Middle Siwaliks) and outcrop scale, non-plunging folds in the proximal hanging wall. We interpret these observations to suggest that (1) elastico-frictional (brittle) deformation processes operated in the fault zone at near surface (∼1–5 km depth) conditions and (2) the folds formed first at the propagating MFT fault tip, then were subsequently dismembered by the fault itself. Thus, we interpret the Mohand Range as a fault-propagation fold driven by an emergent MFT in contrast to the consensus view that it is a fault-bend fold. A fault-propagation fold model is more consistent with these new observations, the modern range-scale topography, and existing erosion estimates. To further evaluate our proposed structural model, we used a Boundary Element Method-based dislocation model to simulate topographic growth from excess slip at a propagating fault tip. Results show that the frontal topography could have evolved by slip along a (a) near-surface fault plane consistent with the present-day MFT location, or (b) blind MFT at ∼3 km depth farther north near the drainage divide. Comparing modelled vs. measured high resolution (∼16 cm) topographic profiles for each case provides permissible end-member scenarios of an either dynamically-evolving, high erosion, northward-migrating frontal scarp or a static, low, and symmetric, MHT-related fold, respectively. Our integrated approach is expected to deliver an improved understanding of coupled fault-generated deformation and topographic growth that may be applied more broadly across the entire Himalayan front.     

Three‐dimensional Evolutionary Models of the Qiongxi Structures,Southwestern Sichuan Basin,China: Evidence from Seismic Interpretation and Geomorphology

Fold terminations are key features in the study of compressional fault-related folds. Such terminations could be due to loss of displacement on the thrust fault or/and forming a lateral or oblique ramp. Thus, high-quality seismic data would help unambiguously define which mechanism should be responsible for the termination of a given fault-related fold. The Qiongxi and Qiongxinan structures in the Sichuan Basin, China are examples of natural fault-propagation folds that possess a northern termination and a structural saddle between them. The folds/fault geometry and along-strike displacement variations are constrained by the industry 3-D seismic volume. We interpret that the plunge of the fold near the northern termination and the structural saddle are due to the loss of displacement along strike. The fault geometry associated with the northern termination changes from a flat-ramp at the crest of the Qiongxinan structure, where displacement is the greatest, to simply a ramp near the northern tip of the Qiongxi structure, without forming a lateral or oblique ramp. In this study, we also use the drainage pattern, embryonic structure preserved in the crest of the Qiongxinan structure and the assumption that displacement along a fault is proportional to the duration of thrusting to propose a model for the lateral propagation of the Qiongxinan and Qiongxi structures. Specifically, we suggest that the structure first initiated as an isolated fault ramp within brittle units. With increased shortening, the fault grows to link with lower detachments in weaker shale units to create a hybridized fault-propagation fold. Our model suggests a possible explanation for the lateral propagation history of the Qiongxinan and Qiongxi structures, and also provides an alternative approach to confirming the activity of the previous Pingluoba structure in the southwestern Sichuan Basin in the late Cenozoic.     

库车冲断带秋里塔格构造带东段构造样式与构造演化

秋里塔格构造带位于库车褶皱冲断前缘,其东段包括东秋里塔格背斜和库车塔吾背斜。野外调查和地震剖面解释表明:秋里塔格构造带东段盐下发育断层转折褶皱; 盐上东秋里塔格背斜为滑脱箱状背斜,库车塔吾背斜核部为南倾逆冲断层所破坏。演化剖面显示秋里塔格构造带东段在侏罗纪断陷期发育了正断裂,其后为平静期,直到库车晚期后逆冲断层和褶皱快速发育,背斜最终形成。膏盐岩及古构造对构造变形具有重要影响,一方面作为滑脱层,分割了盐下层与盐上层,导致二者形成不同的构造样式; 另一方面塑性流动充填于背斜核部。由于膏盐岩的厚度差异,东秋里塔格背斜盐上发育褶皱,而库车塔吾背斜核部被逆冲断层破坏,膏盐层厚度还影响了膏盐层上下构造高点的相对位置。盐下构造的发育受侏罗纪古构造控制,进而影响了盐上构造的发育。     

断层相关褶皱在塔里木盆地玛东地区的应用

玛东褶皱-冲断带是世界上保存最好的早古生代褶皱冲断带之一,也是塔里木油气勘探的重点区域之一。褶皱-冲 断带浅部构造由于遭受强烈剥蚀,为玛东褶皱-冲断带的构造样式和变形机制研究带来巨大的挑战。断层相关褶皱理论定 量化建立了断层形态和褶皱形态几何学和运动学的关系,是一种有效的利用断层形态来推测褶皱形态的方法,为恢复玛东 地区被剥蚀区域的构造形态提供了可能。文中详细介绍了断层转折褶皱和断层传播褶皱的几何学和运动学特征,并将其应 用于玛东地区的典型构造中,建立2 种玛东地区构造变形模式。最后结合工业地震剖面和钻井资料,认为玛东地区的主要 构造样式是断层转折褶皱, 并分析了构造样式对油气圈闭的影响。     

Seismic profile analysis of the Kangra and Dehradun re-entrant of NW Himalayan Foreland thrust belt,India: A new approach to delineate subsurface geometry

In the NW Sub-Himalayan frontal thrust belt in India, seismic interpretation of subsurface geometry of the Kangra and Dehradun re-entrant mismatch with the previously proposed models. These procedures lack direct quantitative measurement on the seismic profile required for subsurface structural architecture. Here we use a predictive angular function for establishing quantitative geometric relationships between fault and fold shapes with ‘Distance–displacement method’ (D–d method). It is a prognostic straightforward mechanism to probe the possible structural network from a seismic profile. Two seismic profiles Kangra-2 and Kangra-4 of Kangra re-entrant, Himachal Pradesh (India), are investigated for the fault-related folds associated with the Balh and Paror anticlines. For Paror anticline, the final cut-off angle \(\beta =35{^{\circ }}\) was obtained by transforming the seismic time profile into depth profile to corroborate the interpreted structures. Also, the estimated shortening along the Jawalamukhi Thrust and Jhor Fault, lying between the Himalayan Frontal Thrust (HFT) and the Main Boundary Thrust (MBT) in the frontal fold-thrust belt, were found to be 6.06 and 0.25 km, respectively. Lastly, the geometric method of fold-fault relationship has been exercised to document the existence of a fault-bend fold above the Himalayan Frontal Thrust (HFT). Measurement of shortening along the fault plane is employed as an ancillary tool to prove the multi-bending geometry of the blind thrust of the Dehradun re-entrant.     

渝东构造样式分析与成因解析

详细的构造分析与解析表明,渝东经历了晚元古代—古生代弱造山与稳定的克拉通盆地、中生代强造山与周缘前陆盆地、新生代造山后与残余盆地3个发育世代;现今构造格局与样式实为多期构造变形形迹的复合、联合与叠加。从总体上看,研究区纵向上可划分为3个构造层,其区域构造形态总体呈现前展式逆冲推覆薄皮构造样式,局部构造共见有7种变形样式。其中,下构造层主要发育双重构造与断弯褶皱;中构造层多发育断弯与断展褶皱;上构造层以形成滑脱、断展与突破构造为主;形成时代大致经历了晚燕山、早喜马拉雅、晚喜马拉雅三期;总体体现西冲的NE向逆冲构造体系形成期最早、东南方向逆冲的NEE向冲褶系形成期其次、东冲的NNE—近SN向逆冲褶皱系形成期最晚。研究区北部构造形成早于中南部,北端NWW—EW向逆冲褶皱系干扰、限制着中北部NE—NEE向逆冲推覆系向北延伸,中部发育的转换(调节)带区段具有比较明显的调节作用。     

龙门山冲断带北段前锋带新生代构造变形

龙门山北段前锋构造的地震剖面解释和前缘盆地内沉积地层的磁组构研究表明前锋构造中发育两期构造挤压作用,即整体强烈的晚三叠世变形和由北向南逐渐减弱的弱新生代构造变形。受这两期构造挤压作用的控制,龙门山北段前锋构造中发育上、下两套构造层,地表构造为晚三叠世时期形成,而深部隐伏构造则形成于新生代。北部的矿山梁和天井山构造几何学上表现为一个双重构造,浅层是一个晚三叠世形成的断层转折褶皱;深层是新生代形成的多个逆冲岩片叠置所构成的隐伏堆垛背斜;南部的青林口和中坝构造主体表现为叠瓦状逆冲,前锋构造是断层转折褶皱和断层传播褶皱。新生代构造冲断位移量以及造成早期构造抬升由北向南逐渐减小,反映新生代变形强度由北向南的减弱。磁组构研究表明新生代变形从龙门山冲断带边缘到盆地内部,磁组构从铅笔状磁组构到初始变形磁组构并逐渐过渡到沉积磁组构。由南向北磁组构由初始变形磁组构转变为铅笔状磁组构,说明应变越来越强,从而进一步证明了龙门山前锋新生代构造的弱变形作用和变形强度的北强南弱分布特征。     

准噶尔盆地南缘中段深层构造变形特征及构造转换关系

准噶尔盆地南缘属于环青藏高原盆山构造系统的一部分,受新生代以来青藏高原远距离构造传递作用的影响,深部构造期次多,变形十分复杂,地震剖面成像品质很差,导致对其构造变形特征和变形机制的认识存在争议,对横向构造转换关系和纵向构造传递过程方面的研究甚少。本文采用最新宽线地震资料,运用断层相关褶皱变形方法分析了准噶尔南缘中段霍玛吐背斜带中-深部隐伏构造变形特征;通过构造样式、变形强度对比与分析,阐述了霍玛吐背斜横向转换关系;在构造建模与精细解释的基础上,利用平衡剖面和构造正演模拟方法,分析了其构造演化过程,并阐述了纵向构造传递过程。分析认为,霍玛吐背斜带深部主要发育低幅度断层转折褶皱,中部发育复合型构造三角楔,并伴生有次级褶皱调节断层及小型反冲断层;浅部发育断层传播褶皱;横向上主要表现为构造样式相近、构造变形强度发生此消彼长的构造转换关系;纵向上表现为侏罗纪—中新世的低幅度构造变形,并以前展式向盆地方向发生构造挤压传递,上新世经强烈逆冲挤压,形成复合构造三角楔及派生的突发构造,后经强烈挤压逆冲,在浅部形成断层传播褶皱,并使山前带被强烈推举地表,遭受剥蚀。     

伸展断层相关褶皱的几何学分析及其在车镇凹陷中的应用

本文总结了伸展断层相关褶皱的发育类型,主要包括伸展断层传播褶皱与伸展断层转折褶皱(也叫断弯褶皱)等.伸展断层传播褶皱多形成在较陡的正断层之上,正断层向上传播使断层顶部地层弯曲,进而形成一个伸展的断层传播褶皱,其发育模式与三剪变形发育模式一致.车镇凹陷是渤海湾盆地南部一个典型的中新生代半地堑盆地.本文通过对横穿车镇凹陷的...     

Experimental (clay) models of inversion structures

Experimental modeling is used to study the geometry and evolution of inversion structures. Two main types of inversion structures are analyzed:

1. (1) structures formed by fault-propagation folding; and

2. (2) structures formed by fault-bend folding on listric faults.

Fault-propagation inversion structures initially develop as broad drape folds with possible fault breakthrough during an early extensional phase. Syn-extensional strata deposited in the hanging wall typically thicken away from the fault. Compressional reactivation results in reversal of slip on the master and secondary faults, their rotation to shallower dips, and the development of a compressional fault-propagation fold. Key features of the fault-propagation fold are basinward thickening of syn-extensional units and resulting steep dips of the front limb of the structure. Fault-bend inversion structures initiate as rollover folds within extensional half-graben. Deformation is primarily localized along a system of antithetic faults. Syn-extensional strata typically thicken across the fault but also thin basinward away from the fault. During compression, the extensional rollover folds are folded into compressional fault-bend folds. Key features of this structure are thinning of syn-extensional units into the basin. Inversion of more symmetric graben results in a doubly-convex geometry of syn-extensional units. These observations of bed geometry and thickness provide predictive models for interpreting the geometries of inversion structures in areas of poor data quality.     

Tectonic repetitions of the Early Cretaceous Agrio Formation in the Chos Malal fold-and-thrust belt,Neuquén Basin,Argentina: Geometry,kinematics and structural implications for Andean building

The Neuquén Basin, developed in a retroarc setting in the central-west of Argentina, contains more than 6000 m of Mesozoic marine and continental sedimentary rocks. These rocks were deformed during the Andean orogeny leading to several thick and thin-skinned fold-and-thrust belts. The Early Cretaceous Agrio Formation is composed by a thick marine succession predominantly of black shales in which highlights a thin fluvial-aeolian sandy interval named Avilé Member. The Avilé Member, one of the most important hydrocarbon reservoirs of the Neuquén Basin, constitutes an excellent structural marker. At the Chos Malal fold-and-thrust belt, the strong mechanical anisotropy given by the contrasting lithology of the Avilé Member within the Agrio Formation favored the location of detachments along the shales and ramps affecting the sandstones during the Andean compression. Detailed field mapping at the Chacay Melehue area allowed us to recognize tectonic repetitions of the Avilé Member, which form imbrications in the simplest case whereas in other places constitute a more complex combination of imbrications, including fault-bend folding that duplicates stratigraphic sequences and fault-propagation folding that deforms more intensely the duplicated units. Along three structural cross-sections we illustrate the geometry of these tectonic repetitions of the Agrio Formation, which in the northern area have an eastward-vergence and in the central and southern regions show a clear westward-vergence. A tear fault along the arroyo Chacay Melehue could explain this vergence change. Forward modeling of the structures at the central cross-section, where a backthrust system produced imbrication, duplication and folding of the Agrio Formation, allows us to propose a balanced kinematic reconstruction of this complex structure and to compare the features produced at different stages of the deformation sequence with field observations. Our kinematic interpretation shows that the tectonic repetitions of the Agrio Formation involve 3 km of shortening above a basal detachment within the lowermost black shales. Based on a regional balanced cross-section constructed from the basement-cored Cordillera del Viento anticlinorium toward the east, across the thin-skinned sector of the Chos Malal FTB, it is possible to connect the backthrust system with east-vergent fault-bend folds that involve the stratigraphic units below the Agrio Formation. Finally, we propose a regional structural model considering the Cordillera del Viento as a basement wedge related to a low angle Andean thrust that is inserted into the sedimentary cover producing structures of different order, which evidence a strong relationship between thick and thin-skinned structures during the Andean orogeny.     

The interplay of fold mechanisms and basement weaknesses at the transition between Laramide basement-involved arches, north-central Wyoming, USA

Horizontally-shortened, basement-involved foreland orogens commonly exhibit anastomosing networks of bifurcating basement highs (here called arches) whose structural culminations are linked by complex transition zones of diversely-oriented faults and folds. The 3D geometry and kinematics of the southern Beartooth arch transition zone of north-central Wyoming were studied to understand the fold mechanisms and control on basement-involved arches.Data from 1581 slickensided minor faults are consistent with a single regional shortening direction of 065°. Evidence for oblique-slip, vertical axis rotations and stress refraction at anomalously-oriented folds suggests formation over reactivated pre-existing weaknesses. Restorable cross-sections and 3D surfaces, constrained by surface, well, and seismic data, document blind, ENE-directed basement thrusting and associated thin-skinned backthrusting and folding along the Beartooth and Oregon Basin fault systems. Between these systems, the basement-cored Rattlesnake Mountain backthrust followed basement weaknesses and rotated a basement chip toward the basin before the ENE-directed Line Creek fault system broke through and connected the Beartooth and Oregon Basin fault systems. Slip was transferred at the terminations of the Rattlesnake Mountain fault block by pivoting to the north and tear faulting to the south. In summary, unidirectional Laramide compression and pre-existing basement weaknesses combined with fault-propagation and rotational fault-bend folding to create an irregular yet continuous basement arch transition.     

东濮凹陷古近系伸展褶皱及形成机理

东濮凹陷是一个新生代裂陷盆地,古近纪为裂陷期,形成各种各样的褶皱构造及具有潜力的圈闭构造。本文在地震资料解释基础上,对东濮凹陷褶皱类型进行划分,讨论褶皱形成机制和油气地质意义。东濮凹陷古近纪褶皱,按照褶皱轴向与断层走向关系分为纵向、横向和斜向褶皱;按照褶皱与断层的成因联系,可划分为断弯褶皱、断展褶皱和变换褶皱等。褶皱作用分三个时期,即始新世、渐新世和始新世–渐新世。褶皱的形成机理为顺层剪切滑动和切层剪切滑动。褶皱的形成与断层紧密相关,是断面形态、断层多期活动和断层位移变化的结果。东濮凹陷油气圈闭与褶皱存在直接或间接的关系。     

Mechanical stratigraphy as a factor controlling the development of a sandbox transfer zone: a three-dimensional analysis

In thrust belts, fold–fault terminations are common features of the structural architecture and can pose complicated problems to unravel, in particular when two or more terminations are in close proximity. Such terminations usually reflect pre-existing attributes. Amongst the many factors, lateral variations in the mechanical stratigraphy can control along-strike geometry and kinematics of fault-related folds.A displacement transfer zone was produced in a compressional sandbox model by means of two adjacent, mechanically different stratigraphic domains. The experiment allowed two discrete chains to develop in the different domains, so that a complex structural setting occurred in the connecting area. Periclinal folds, oblique thrust fronts and oblique ramps developed in the resulting transfer zone. The interaction between periclines in the transfer zone produced lateral culminations in the folded structures. The analysis of displacement across the structural domains revealed that a significant loss of slip along the faults occurred in the relay zone. In this area, imbricate faulting was partially replaced by layer-parallel shortening. A linear relationship appears to exist between the bed length of the thrust sheet and the related fault slip.     

Superposed folding of a blind thrust and formation of klippen: results of anisotropic magnetic susceptibility studies from the Lesser Himalaya

The rocks of the Garhwal Lesser Himalaya have undergone a weak superimposed deformation, hence linear and planar structures are either absent or poorly developed. This puts a severe limitation on application of conventional methods of finite strain determination in understanding the deformation pattern. However, the geometry, orientation, and distribution of magnetic susceptibility strain ellipses clearly reveal the effects of early and superposed deformations in the area. The orientation patterns of the ellipses also help to identify reversal of displacement along an oblique fault ramp during the superposed deformation. The Hrouda double plot reveals a combination of lateral shortening and simple shear, thereby suggesting a small translation along the klippe detachment thrust. The study has important implications for understanding the structural evolution of the Lesser Himalayan klippen, because the earlier models, in the absence of the relevant data, are based on assumptions concerning thrust displacement. The present field studies and the AMS data favour an alternate model for the structural evolution of the Lesser Himalayan klippen, that lie in the core of the Mussoorie Syncline. The model explains structural features and outcrop patterns as due to a combination of fault bifurcation, back thrusts, pop-up, and subsequent superposed deformation. The klippen lie over their roots and are described as pop-up klippen.     

塔里木盆地玉东-玛东构造带断层相关褶皱样式及演化

玉东-玛东构造带位于塔里木盆地,是在中寒武统膏盐层上滑脱的大规模褶皱冲断带,内部发育多种断层相关褶皱。目前对此构造带的研究,多关注了构造带的局部以及断裂变形。本文根据断层相关褶皱理论,利用地震资料,分析了玉东-玛东构造带内构造样式上的差异性,并通过二维构造正演模拟,建立了典型构造样式的运动学模式。认为研究区内玉东、玛东、塘北3个分区,具有不同的构造样式。玉东地区主要发育和铲式逆断层相关的断弯褶皱,玛东、塘北地区则发育断层突破的滑脱褶皱,突破断层在玛东地区为铲式断裂,而在塘北地区为坪-坡-坪式断裂。根据上奥陶统变形特征及其顶面不整合面之上的地层年代,认为玉东-玛东构造带的变形始于晚奥陶世,主要断裂及其相关褶皱形成于晚奥陶世末期。玉东地区在晚奥陶世早期,形成基底-盖层的低幅褶皱,在晚奥陶世末,形成铲式断裂及断弯褶皱;玛东和塘北地区变形发生在上奥陶统沉积之后,经历了滑脱褶皱和断层突破阶段。通过对比分析认为,断层相关褶皱样式的差异,与膏盐层岩性、厚度,上奥陶统岩性、厚度及构造转换作用有关。本研究有助于完善对塔里木盆地早古生代末期构造变形及演化的认识。