首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
The Kemalpa?a Basin is one of the Quaternary basins in Western Anatolia and represents the south-western branch of the Gediz Graben system in this extensional province. This basin has been formed under the NNE–SSW trending extensional tectonic regime. It is bounded by a major fault, the Kemalpa?a Fault, in the south and it is bounded by a number of downstepping faults, called as Spilda?? Fault Zone, in the north. Both margin-bounding faults of the Kemalpa?a Basin are oblique-slip normal faults. In order to better understand the activities of these faults, we investigated the tectonic geomorphology of the Kemalpa?a Basin and interpreted the effect of tectonic activity on the geomorphological evolution using geomorphic markers such as drainage basin patterns, facet geometries and morphometric indices such as hypsometric curves and integral (HI), basin shape index (Bs), valley floor width-to-height ratio (Vf) and mountain front sinuosity (Smf). The morphometric analysis of 30 drainage basins in total and mountain fronts bounding the basin from both sides suggests a relatively high degree of tectonic activity. The mountain front sinuosity (Smf) generally varies from 1.1 to 1.3 in both sides of the basin suggesting the active fronts and facet slopes (12°–32°) suggest a relatively high degree of activity along the both sides of the Kemalpa?a Basin. Similarly, the valley floor width-to-height ratios (Vf) obtained from the both sides indicate low values varying from 0.043 to 0.92, which are typical values (<1) for tectonically active mountain fronts. The all values obtained are lower for the southern side. Therefore, we suggest that the tectonic activity of the Kemalpa?a Fault higher than the Spilda?? Fault Zone. This difference that can be arised from the different uplift rates also reveals the typical asymmetric characteristics of the Kemalpa?a Basin. Additionally, the trapezoidal facets which have been observed on the southern side of the basin indicate that the Kemalpa?a Fault is evolutionally more active as compared to the Spilda?? Fault Zone. The geomorphic indices indicate that the Quaternary landscape evolution of the Kemalpa?a Basin was governed by tectonic and erosional processes, and also the all results of morphometric analysis suggest a relatively high degree of tectonic activity along the faults bounding the Kemalpa?a Basin. Moreover, considering that active large normal faults with an average 15 km long can cause major earthquake, the earthquake hazard in the Kemalpa?a Basin should be investigated in detailed paleoseismological studies.  相似文献   

2.
The easternmost sector of the Gulf of Corinth, the Beotia area in Central Greece, is an area with active normal faults located between the two major rift structures of Central Greece, the Gulf of Corinth and the North Gulf of Evia. These active normal faults include WNW to E–W and NE to ENE-trending faults affect the landscape and generate basin and range topography within the Beotia. We study four normal fault zones and drainage basin geometry in the easternmost sector of the Gulf of Corinth to document the impact of active tectonics on the landscape evolution. Fault and drainage geometry are investigated based on detailed field mapping and high-resolution digital elevation models. Tectonic geomorphic analysis using several parameters of active tectonics provides information concerning the relative tectonic activity and fault growth. In order to detect areas of lateral stream migration that could indicate recent tectonic activity, the Transverse Topographic Symmetry Factor and the Asymmetry Factor are used to analyse drainage basin geometry in six large drainage basins and a drainage domain covering the study area. Our results show that vertical motions and tilting associated with normal faulting influence the drainage geometry and its development. Values of stream-gradient indices (SL) are relatively high close to the fault traces of the studied fault zones suggesting high activity. Mountain-front sinuosity (Smf) mean values along the fault zones ranges from 1.08 to 1.26. Valley floor width to valley height ratios (Vf) mean values along the studied fault zones range between 0.5 and 1.6. Drainage basin shape (BS) mean values along the fault zones range from 1.08 to 3.54. All these geomorphic parameters and geomorphological data suggest that the analyzed normal faults are highly active. Lateral fault growth was likely produced by primarily eastward propagation, with the WNW to E–W trending faults being the relatively more active structures.  相似文献   

3.
This paper investigates the impact of active tectonics on the geomorphic processes and landscape evolution along the Kazerun Fault Zone (KFZ) in the Zagros Mountains of Iran using spatial analysis of geomorphic indices. We document how topography and morphology are influenced by active tectonic deformation. The Zagros fold–thrust belt is an area of active crustal shortening where northwest–southeast oriented fault‐related folds become younger from north to south and from southeast to northwest. This temporal and spatial evolution of the belt was tested using geomorphic indices of active tectonics that include mountain front sinuosity index (Smf), the valley width/height ratio (Vf), drainage basin asymmetry factor, hypsometric integral, drainage basin shape ratio and mean axial slope of the channel. Change in the geomorphic indices is the result of active fold growth and change in the uplift rate. Decreasing Smf and Vf values from north (Smf = 2.01; Vf = 0.5) to south (Smf = 1.12; Vf = 0.2) and from southeast (Smf = 1.84; Vf = 0.8) to northwest (Smf = 1.54; Vf = 0.1) points to a migration of the active crustal shortening towards W–SW. The combined geomorphic (field evidences) and morphometric data (quantitative analysis of geomorphic indices) provide evidence of relative variation in the tectonic activity along the Kazerun Fault Zone and related landforms. The utilization of geomorphic parameters with comparison to the field observations exhibits change in relative tectonic activities mostly corresponding to the change in mechanism of the prominent fault zones in the study area. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

4.
The Tien Shan is one of the most active intracontinental mountain belts exhibiting numerous examples of Quaternary fault-related folding. To provide insight into the deformation of the Quaternary intermontane basins, the territory of the northwestern Ysyk-Köl region, where the growing Ak-Teke Anticline divided the piedmont apron of alluvial fans, is studied. It is shown that the Ak-Teke Hills are a sharply asymmetric anticline, which formed as a result of tectonic uplift and erosion related to motions along the South Ak-Teke Thrust Fault. The tectonic uplift gave rise to the local deviation of the drainage network in front of the northern limb of the fold. Optical (luminescent) dating suggests that the tectonic uplifting of the young anticline and the antecedent downcutting started 157 ka ago. The last upthrow of the high floodplain of the Toru-Aygyr River took place 1300 years ago. The structure of the South Ak-Teke Fault is examined by means of seismologic trenching and shallow seismic profiling across the fault. A laser tachymeter is applied to determine the vertical deformation of alluvial terraces in the Toru-Aygyr River valley at its intersection with the South Ak-Teke Fault. The rates of vertical deformation and an inferred number of strong earthquakes, which resulted in the upthrow of Quaternary river terraces of different ages, are calculated. The study territory is an example of changes in fluvial systems on growing folds in piedmont regions. As a result of shortening of the Earth’s crust in the mountainous belt owing to thrusting, new territories of previous sedimentation are involved in emergence. The tectonic activity migrates with time from the framing ridges toward the axial parts of intramontane basins.  相似文献   

5.
Spatial differences of Quaternary deformation and intensity of tectonic activity are assessed through a detailed quantitative geomorphic study of the fault‐generated mountain fronts and alluvial/fluvial systems around the Maharlou Lake Basin in the Zagros Fold–Thrust Belt of Iran. The Maharlou Lake Basin is defined as an approximately northwest–southeast trending, linear, topographic depression located in the central Zagros Mountains of Iran. The lake is located in a tectonically active area delineated by the Ghareh and Maharlou faults. Combined geomorphic and morphometric data reveal differences between the Ghareh and Maharlou mountain front faults indicating different levels of tectonic activity along each mountain front. Geomorphic indices show a relatively high degree of tectonic activity along the Ghareh Mountain Front in the southwest, in contrast with less tectonic activity along the Ahmadi Mountain Front northeast of the lake which is consistent with field evidence and seismotectonic data for the study area. A ramp valley tectonic setting is proposed to explain the tectonosedimentary evolution of the lake. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

6.
Field data from an orogenic foreland and an orogenic belt (the Mesozoic rocks of southern England and the Umbria‐Marche Apennines of Italy respectively) indicate the following. Firstly, stress evolution during the tectonic cycle, between maximum compressive stress (σ1) being vertical during extension and least compressive stress (σ3) being vertical during contraction, can involve phases when the intermediate compressive stress (σ2) is vertical, promoting strike‐slip deformation. Secondly, variations in the relative magnitudes of the stress axes are caused by variations in overburden and tectonic forces. Thirdly, overpressure can develop because of compaction during burial, and, as overburden is reduced during uplift and erosion, the vertical stress (σV) reduces but fluid pressure (Pf) remains approximately constant. Brittle deformation, including transient strike‐slip faults, reverse‐reactivated normal faults and normal‐reactivated thrusts, is preferentially developed in overpressured areas because high Pf promotes faulting.  相似文献   

7.
We study the margin of South East Deccan Volcanic Province around Kinwat lineament, Maharashtra, India, which is NW extension of the Kaddam Fault. Structural field studies document \(\sim \)E–W strike-slip mostly brittle faults from the basement granite. We designate this as ‘Western boundary East Dharwar Craton Strike-slip Zone’ (WBEDCSZ). At local level, the deformation regime from Kinwat, Kaddam Fault, micro-seismically active Nanded and seismically active Killari corroborate with the nearby lineaments. Morphometric analyses suggest that the region is moderately tectonically active. The region of intense strike-slip deformation lies between seismically active fault along Tapi in NW and Bhadrachalam in the SE part of the Kaddam Fault/lineament. The WBEDCSZ with the surface evidences of faulting, presence of a major lineaments and intersection of faults could be a zone of intraplate earthquake.  相似文献   

8.
There are plenty of faults that show evidence that they are active. Most of the valley’s floor is occupied by unconsolidated Karewa deposits, in particular on the south–southwest of the Kashmir Valley. In such situations, geomorphic data can reveal the location of active faults. Accordingly, we tried to identify geomorphic indices in SW of the Kashmir Valley (Veshav, Rambiara, and Romushi drainage basins), which revealed the area to be potentially tectonically active. This active faulting was further substantiated by drainage anomalies and field investigations, which provides evidence for an emergent out-of-sequence NE-dipping active reverse fault (identified first time on ground) named the Balapur Fault (BF). The BF can be traced over at least 40 km along the southwest side of the Kashmir Valley. The existence of the active Balapur Fault and of two other inferred faults north of the Panjal Thrust or Murree Thrust presents a picture of a more complex strain-partitioning regime in the Kashmir Himalayas than is usually visualized.  相似文献   

9.
Based on the analysis of newly collected data of plate tectonics, distribution of active faults and crustal deformation, the Taiwan area is divided into two seismic regions and six seismic belts. Then, correlation fractal dimensions of all the regions and belts are calculated, and the fractal characteristics of hypocenteral distribution can be quantitatively analyzed. Finally, multifractal dimensions Dq and f(α) are calculated by using the earthquake catalog of the past 11 years in the Taiwan area. This study indicates that (1) there exists a favorable corresponding relationship between spatial images of seismic activity described with correlation fractal dimension analysis and tectonic settings; (2) the temporal structure of earthquakes is not single but multifractal fractal, and the pattern of Dq variation with time is a good indicator for predicting strong earthquake events.  相似文献   

10.
The Pacific–Australian tectonic plate boundary through the South Island of New Zealand consists of the transpressional Southern Alps mountain belt and the transcurrent Marlborough Fault System, both of which have active tectonically driven hydrothermal systems, with topographically driven meteoric incursion and warm springs. The Southern Alps hydrothermal system is relatively diffuse, with little or no fault control, and is channelled through scattered extensional sites beneath the mountains, where gold mineralisation is occurring locally. The hydrothermal activity along the Marlborough Fault System is controlled by the principal faults in well-defined valleys separated by narrow high ridges. Lateral evolution of Marlborough fault strands southwestwards into the Southern Alps has caused diversion of diffuse Southern Alps hydrothermal activity into the structural superimposition zone, where fluid flow is increasingly being controlled by faults. This hydrothermal diversion was accompanied by major topographic reorientation and river drainage reversal in the late Quaternary. Vein swarms now exposed in the remnants of the Southern Alps north of the superimposition zone formed at shallow levels, with some evidence for fluid boiling, from a mixture of meteoric and deep-sourced fluid. These veins, some of which contain gold, are part of an abandoned <1 million-year-old hydrothermal zone beneath the fossil topographic divide of the Southern Alps that has now been dismembered by lateral incursion of the Marlborough fault strands. Observations on this active plate boundary provide some insights into processes that controlled orogenic gold mineralisation in ancient belts, particularly with respect to relationships between hydrothermal fluid flow, structure and topography.  相似文献   

11.
Deep-seated gravitational slope deformations (DSGSDs) influence landscape development in tectonically active mountain ranges. Nevertheless, the relationships among tectonics, DSGSDs, and topography are poorly known. In this paper, the distribution of DSGSDs and their relationships with tectonic structures and active processes, surface processes, and topography were investigated at different scales. Over 100 DSGSDs were mapped in a 5000 km2 sector of the central Eastern Alps between the Valtellina, Engadine and Venosta valleys. Detailed lineament mapping was carried out by photo-interpretation in a smaller area (about 750 km2) including the upper Valtellina and Val Venosta. Fault populations were also analysed in the field and their mechanisms unravelled, allowing to identify different structural stages, the youngest being consistent with the regional pattern of the ongoing crustal deformation. Finally, four DSGSD examples have been investigated in detail by geological and 2D geomechanical modelling.DSGSDs affect more than 10% of the study area, and mainly cluster in areas where anisotropic fractured rock mass and high local relief occur. Their onset and development is subjected to a strong passive control by mesoscopic and major tectonic features, including regional nappe boundaries as well as NW–SE, N–S and NE–SW trending recent brittle structures. The kinematic consistency between these structures and the pattern of seismicity suggests that active tectonics may force DSGSDs, although field evidence and numerical models indicate slope debuttressing related to deglaciation as a primary triggering mechanism.  相似文献   

12.
The relationship between deformation and so-called fluid paleotransfers in minor faults has been analysed in an argillaceous formation located in the Causses Basin in France. The fluid paleotransfers are related to the fault activity to a large extent. We attempt to estimate the intensity of paleo-deviatoric stress magnitudes under which the fault activity may have occurred and consequently, the change in the structural fault permeability. The paleo-deviatoric stress magnitudes were calculated with the inverse method of Etchecopar applied to calcite twinning. The measured crystals are contained within the core zone of minor faults and this study is based on a previous complete microtectonic and microstructural analysis of the faults. In this paper, analysis of calcite twinning has been applied for the first time to vein fillings associated small faults in a context of relatively weak deformation, a condition ensured by the tectonic and structural analysis. Calculation and discussion of the paleo-deviatoric stress tensors in relation to the evolution of the structural fault permeability and to the hydraulic behaviour of the faults are the aim of this paper. The analysed faults, created and active during the same tectonic event, were permeable under a (σ1–σ3) mean value of 40–50 MPa. On the other hand, the reactivation of faults during a second tectonic event implies mean (σ1–σ3) value higher than 40–50 MPa, especially for the faults that are poorly oriented with respect to the principal tectonic stress directions. The core zone of these faults remained sealed and impermeable or became permeable by development of microcracks inside the pre-existing fillings.  相似文献   

13.
《International Geology Review》2012,54(12):1557-1567
ABSTRACT

The present-day tectonic framework of Turkey comprises mainly two strike-slip fault systems, namely dextral North Anatolian and sinistral East Anatolian faults. They are considered as the main cause of deformation patterns in Anatolia. These two mega shear systems meet at Kargapazar? village of Karl?ova county. The area to the east of the junction has a transpressional tectonic regime between the Eurasian and Arabian plates and is characterized, based on field observation, by a network of faults defining a typical horsetail splay structure. The horsetail splay is interpreted as marking the termination of the North Anatolian Fault System (NAFS), which continues eastward into the Varto Fault Zone (VFZ) and then dies out. The present study reveals that the VFZ is made up of two main parts, namely the principal displacement zone (PDZ) and the transpressional splay zone (TPSZ), both characterized by the right-lateral strike-slip with reverse motion. However, the area to the east of Varto is characterized dominantly by reverse-thrust faults and E–W-trending faults as shown by focal mechanism solutions. The generation of the VFZ as a transpressional termination to the NAFS can be related directly to the block movements of the Eurasian, Anatolian, and Arabian plates.  相似文献   

14.
Western Anatolia is one of the world’s most seismically active regions. A nearly N–S-oriented extension caused the formation of E–W- and NE–SW-trending major grabens, creating the potential for earthquakes with magnitudes ≥ 5. The fault segments of the NE-trending Çameli Basin were evaluated using geomorphic indices, common tools for assessment of relative tectonic activity in such areas. Quantitative measurement of geomorphic indices including mountain-front sinuosity (Smf; 1.35–2.39), valley floor width-to-height ratios (Vf; 0.08?0.37), and hypsometric integral (HI; 0.31–1.05) suggest relatively higher tectonic activity along western and southern part of the basin. Hypsometric curves for all segments of the faults mostly exhibit concave or straight profiles, signifying existence of young mountain fronts in the Çameli Basin. These calculations indicate that the Çameli Basin is tectonically active and, southern/south-western areas of this depression have earthquake potential, consistent with epicentres of recent earthquakes, occurred along some fault segments. Possible reason of this activity seems to be related to the E–W-trending corridor lying between the Gulf of Gökova and south-eastern part of the Çameli Basin, represented by active normal faults. These findings should be valid beyond the Çameli Basin for similar situations along the Isparta Angle’s western margin.  相似文献   

15.
敦密断裂带白垩纪两期重要的变形事件   总被引：1，自引：1，他引：0  
本文报道了敦密断裂带糜棱岩中黑云母~(40)Ar/~(39)Ar定年结果和大规模走滑-逆冲断裂的几何学、运动学特征及其形成时代,以便揭示断裂带两期变形事件的构造属性。黑龙江省密山市花岗质糜棱岩中黑云母~(40)Ar/~(39)Ar加权平均年龄为132.2±1.2Ma,它是敦密断裂带经历伸展事件的冷却年龄,也是东北亚大陆边缘在早白垩世Hauterivian期-Albian期发生强烈区域伸展作用的产物。密山市至辽宁省清原县系列大型走滑-逆冲断层和断层相关褶皱揭示出在晚白垩世晚期-末期发生右旋走滑-逆冲事件,该事件规模大,影响范围广,导致整个断裂带遭受到强烈改造,形成对冲式断裂系统。将研究区走滑-逆冲断裂与山东省郯庐断裂带中段挤压构造对比,认为郯庐断裂带北段和中段在晚白垩世末期都发生了强烈的走滑-逆冲事件,它们具有相同的构造特征和构造属性。  相似文献   

16.
We present an overview of the seismogenic sources of northeastern Italy and western Slovenia, included in the last version of the Database of Individual Seismogenic Sources (DISS 3.0.2) and a new definition of the geometry of the Montello Source that will be included in the next release of the database. The seismogenic sources included in DISS are active faults capable of generating Mw > 5.5 earthquakes. We describe the method and the data used for their identification and characterization, discuss some implications for the seismic hazard and underline controversial points and open issues.In the Veneto–Friuli area (NE Italy), destructive earthquakes up to Mw 6.6 are generated by thrust faulting along N-dipping structures of the Eastern Southalpine Chain. Thrusting along the mountain front responds to about 2 mm/a of regional convergence, and it is associated with growing anticlines, tilted and uplifted Quaternary palaeolandsurfaces and forced drainage anomalies. In western Slovenia, dextral strike–slip faulting along the NW–SE trending structures of the Idrija Fault System dominates the seismic release. Activity and style of faulting are defined by recent earthquakes (e.g. the Ms 5.7, 1998 Bovec–Krn Mt. and the Mw 5.2, 2004 Kobarid earthquakes), while the related recent morphotectonic imprint is still a debated matter.We reinterpreted a large set of tectonic data and developed a segmentation model for the outermost Eastern Southalpine Chain thrust front. We also proposed the association of the four major shocks of the 1976 Friuli earthquake sequence with individual segments of three major thrust fronts. Although several sub-parallel active strike–slip strands exist in western Slovenia, we were able to positively identify only two segments of the Idrija Fault System. A comparison of the regional GPS velocity with long-term geological slip-rates of the seismogenic sources included in DISS shows that from a quarter to half of the deformation is absorbed along the external alignment of thrust faults in Veneto and western Friuli. The partitioning of the deformation in western Slovenia among the different strike–slip strands could not be quantified.  相似文献   

17.
角木日地区位于羌塘盆地中部,构造位置处于冈瓦纳和欧亚大陆板块结合部的北缘。新生代以来,青藏高原的强烈隆升使得角木日地区新构造运动活跃,在江爱藏布、冈塘错一带发育有多条NE向和近NS向活动断裂带。这些断裂包括新近纪以来的新活动断裂,也包括一些基底老断裂的复活,其活动强烈制约了该区的地形地貌、水系格局、沉积物分布、地下热液活动和生态环境。长期以来,沿着这些活动断裂带地震活动频繁,严重影响了当地的人类生存自然地理环境。通过对区内湖泊、沼泽、温泉的水文、第四纪地质方面观察和活动构造研究,发现江爱藏布西热泉中含有较高浓度的有机质,不仅具有重要的构造意义,而且对寻找油气资源具有指示意义。  相似文献   

18.
Alaknanda river basin is considered to be tectonically active where damaging earthquakes and landslides have occurred. The whole basin was divided into 8 sub-basins to carry out morphometric analyses, hypsometric integral (HI) analysis and valley floor width to valley height ratio (V f) factor. The sub-basins 2 and 3 show that they are highly active, because of the higher values of bifurcation ratio, stream frequency asymmetric factor, and lower values of form factor, elongation ratio and circulatory ratio. In these areas, HI values are very low indicating that the landscape is highly eroded, deeply dissected and tectonically active. The result obtained from V f was similar which classified both these basins as highly active. Morphometric analysis, HI and V f analyses along with structural map of study area are used to prepare morpho-tectonic map classifying the whole area into very high, high, moderate and low zones of tectonic activity. This map clearly indicates that the areas near MCT II (Munsiari Thrust), MCT III (Ramgarh Thrust) and North Almora Thrust are tectonically very active which fall in sub-basins 2, 3, 4 and parts of 5. Various locations such as Chamoli, Birahi, Pipalkoti, Rudraprayag, etc. are situated in these zones where many earthquakes and landslides occur every year. Moreover, the data plotted for earthquakes and landslides occurrences are consistent with morpho-tectonic map and can be used as a precursor for demarcation of natural hazard vulnerable zones.  相似文献   

19.
The Kachchh region of Western India is a pericratonic basin experiencing periodic high magnitude earthquakes events. In 2001 a catastrophic seismic event occurred at Bhuj measuring Mw = 7.7. The epicenters of both the 1956 and 2001 earthquakes were along the Kachchh Mainland Fault (KMF), proximal to the eastern end of the Northern Hill Range (NHR). The latter is a topographic expression of an active fault related fold on the hanging wall, and is controlled by a south dipping blind thrust.The present study deals with the eastern sector of NHR and uses optical dating to reconstruct the chronology of tectonically caused incisions. Along the backlimb of the NHR, incision ages on, channel fills and valley fill terraces progressively decrease from  12 ka to 4.3 ka. This age progression along with geomorphic evidences (decrease in topographic relief, drainage capture and drainage migration across the fold nose) suggests an active vertical and lateral fold growth along the KMF. Optical ages suggest that during the Late Holocene, the average uplift rate along the eastern NHR was 10 ± 1 mm/a. Recent GPS based estimates on crustal shortening are  12 mm/a.The KMF and the South Wagad Fault (SWF) represent the bounding faults of a transtensional basin that formed during the initial rifting. This basin is termed as the Samakhiali basin. The compressive stresses on account of structural inversion from normal to reverse phase resulted in lobate-shaped anticlines along KMF and SWF zone. These anticlines subsequently coalesced and formed linked and overlap segments. The present study suggests that eastward lateral deformation across the eastern portion of KMF has continued and has now resulted in its interaction with a left step over transfer fault called the South Wagad Master Fault (SWMF). This implies an increasing transpersional deformation of the Samakhiali basin. We therefore, suggest that the eastward NHR ridge propagation along KMF resulted in the thrust faulting on the south dipping SWMF resulting in the Bhuj 2001 event. The increasing strain on this basin may cause enhanced seismicity in the future along the eastern KMF and Wagad region.  相似文献   

20.
断裂是塔中隆起带东段构造变形的主要方式,也是控制油气成藏与分布的重要因素,其形成机制和过程一直存有争议。文章从李四光教授构造体系理论出发,通过综合解析塔中隆起带东段断裂的几何学、运动学及动力学特征,探讨了塔里木盆地中央隆起带东部"帚状构造体系"形成的地球动力学模型。研究结果显示:塔里木盆地古生代以来受天山、西昆仑山和阿尔金山三大褶皱山系的影响,伴随盆地三个"伸展-聚敛"构造旋回的发展和演化;中央隆起带东段的塔中Ⅰ号断裂、塔中10号断裂、塔中Ⅱ号断裂和卡塔克南缘断裂等断裂于加里东早期产生,并于随后多次活动,它们在剖面上呈现"Y"字型结构,平面上向东南收敛、向西北撒开,和南侧的塘南断裂及车尔臣断裂共同构成"帚状构造"体系;加里东运动以来,该构造体系先后经历了张扭性（加里东早期）→压扭性（加里东中期）→张扭性（海西早起）→压扭性（海西晚期）两大应力场的转换,并于海西晚期基本定型,同时在其周邻地区产生北东、北东东向的次级的、低序次的断裂体系。   相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号