共查询到20条相似文献，搜索用时 31 毫秒
1.
Segmentations of foreland belts and their tectonic mechanism in the Southwest Tarim Basin 总被引：2，自引：0，他引：2
Many geologists focus on the foreland structures, co-relationship between shallow and deep structures and their dynamics between intra-continent orogenies and foreland basin in recent years[1―17]. The intra-plate collision and deformed area of West Kunlun-Pamirand Southern Tianshan become the natural lab of this studies and there are many new developments con-cerned with the geometry and kinemics of foreland thrusting, back-thrusting and triangle zones[3―14]. Many types of foreland thrusti… 相似文献
2.
总结分析了第２９届国际地质大会上有关含油气盆地分析中某些方面的进展，主要包括：（１）弧后及大陆裂谷盆地、克拉通盆地、前陆盆地以及与走滑作用有关的盆地形成的地球动力学背景及形成机理分析；（２）利用砂岩岩石学和火山岩地球化学特征探讨盆地形成的构造背景及其演化；（３）层序地层学在分析沉积盆地沉积充填特征及历史、识别和预测储集砂体、预测源岩分布及有机质丰度中的应用；（４）盆地发育过程中主要地质作用的数值模拟；（５）油气生成、运移和聚集的数值模拟。 相似文献
3.
通过大量野外地质调查和深部物探（地震剖面、MT和重力）综合构造解释，在位于东起八盘水磨，西对乌鲁克恰特以西的南天山前陆冲断带中，确定了阿图什－八盘水磨反冲构造系统及其三角带构造；该反冲系统由小阿图什－八盘水磨和乌尔－喀拉套山反冲构造系统及小阿图什－乌鲁克恰特被变形的反冲构造系统组成；即在以往认为南天山向塔里木盆地大规模中推覆的地区，塔里木盆地美国层第四纪以来沿多组滑脱面向天山新生代造山带反冲推覆。塔里木盆地反冲构造系统发育的区域基底埋深往往大于10km，对应麦盖提基底构造下凹区，而相邻柯坪塔格薄皮推覆构造系统发育的区域基底埋深一般小于10km,对应巴楚基底构造上隆区；逆冲和反冲构造转换带基底埋深约10km,平衡剖面恢复表明弧形逆冲和反冲构造顶部分别为逆冲和反冲位移量最大位置。 相似文献
4.
Paleoenvironments of the evolving Pliocene to early Pleistocene foreland basin in northwestern Taiwan: An example from the Dahan River section 
下载免费PDF全文
下载免费PDF全文 The overriding of the Luzon volcanic arc atop the underlying Chinese rifted‐continental margin has caused the formation of the Taiwan mountain belts and a peripheral foreland basin west of the orogen since the late Miocene. In this study, lithofacies analysis and calcareous nannofossil biostratigraphic investigations of the Dahan River section in northwestern (NW) Taiwan were performed. Our results offer insights into the temporal evolution of the sedimentary environments and the competing effects of the sedimentation and basin tectonics of the NW Taiwan foreland basin from the Pliocene to early Pleistocene. Nannofossil biostratigraphic studies showed that the upper Kueichulin Formation and the overlying Chinshui Shale can be assigned to the NN15 biozone of the Pliocene age, and the Cholan Formation pertains to NN16–NN18 of the early Pleistocene. The NN15–NN16 boundary coincides roughly with the boundary of the Chinshui Shale and Cholan Formation. We recognized three major sedimentary environments in the studied foreland succession comprising the upper Kueichulin Formation, Chinshui Shale, Cholan Formation and Yangmei Formation, in ascending order. During the deposition of the upper Kueichulin Formation in the early Pliocene, the dominant environment was a wave‐ and tide‐influenced open marine setting. During the late Pliocene, the environment deepened to an outer‐offshore setting when the sediments of Chinshui Shale were accumulated. In the Pleistocene, the environment then shallowed to wave‐dominated estuaries during the deposition of the lower Cholan Formation, and the basin was rapidly filled, generating a meandering and sandy braided river environment during the deposition of the upper Cholan to the Yangmei Formation. In summary, the evolution of sedimentary environments in the studied succession shows a deepening then a shallowing and coarsening upward trend during the period from the Pliocene to the Pleistocene, spanning the age from approximately 4 to 1 Ma. 相似文献
5.
龙门山中南段前陆区是青藏高原东缘唯一发育新生代薄皮构造与沉积盆地的地段,研究其最新构造变形样式有助于深入理解青藏高原向东扩展的构造机理.论文通过青衣江河流阶地测量与古青衣江洪积扇形态重建,研究了龙门山南段前陆区晚第四纪活动构造格局及其活动性,取得了如下认识：（1）青衣江河流阶地纵剖面显示,龙门山南段前陆地区晚第四纪变形主要为褶皱作用,总体地壳缩短速率为2.5~3.9 mm·a-1,远大于山区冲断带0.48~0.77 mm·a-1的地壳缩短速率,地壳缩短主要由前陆地区吸收;（2）青衣江古洪积扇错断变形显示,龙门山南段前陆区活动构造表现为北西—南东向地壳缩短与近东西向的地壳缩短的叠加作用,两者分别受控于巴颜喀拉块体南东向推挤作用与川滇块体向东推挤作用;（3）自中新世初川滇块体向南东挤出,四川盆地西南角起到分流青藏高原物质的作用,其西南侧物质通过鲜水河—小江断裂带的左旋错动向南东方向分流,其西北侧物质通过龙门山断裂带的右旋错动向北东方向分流,迎面受到了最大的推挤作用,进而向前陆扩展形成了薄皮褶皱构造带. 相似文献
6.
秦岭-大别造山带横贯中国大陆中部,并将我国东部分为南北两部;即华北克拉通和扬子克拉通.在南、北相向运动力系驱动下构成了一个极为复杂的复合、叠加构造带、成矿带和地震活动带.同时导致了该地域异常变化的沉积建造和强烈起伏的结晶基底.然而对它们形成的地球物理边界场响应,岩相和结构的异常变化尚不清晰,特别对盆山之间的耦合响应更缺乏深层动力过程的理解.为此本文通过该区榆林-铜川-涪陵长1000 km剖面的地震探测和研究结果提出：（1）沉积建造厚度变化为4~10 km,结晶基底起伏强烈,幅度可达4~6 km;（2）一系列基底断裂将该区切割为南鄂尔多斯盆地和秦岭北缘前陆盆地、秦岭-大巴造山带和南缘前陆盆地与东北四川盆地,其中前陆盆地为秦岭北渭河盆地和秦岭南通江-万源盆地;（3）秦岭造山带是北部华北克拉通向南推挤、南部扬子克拉通向北推挤下隆升的陆内山体,并构筑了其南、北前陆盆地;（4）秦岭造山带的南、北边界并非是一条边界断层,而应是包括前陆盆地在内的组合界带;（5）秦岭与大巴弧形山系源于同一深部结晶基底,即同根生.这一系列的新认识对深化理解秦岭-大巴造山带形成的深层动力过程和演化机理及厘定扬子克拉通的真实北界具有极为重要的意义. 相似文献
7.
8.
9.
B.P. Singh 《Earth and Planetary Science Letters》2003,216(4):717-724
The evolution of the Himalayan foreland is the result of continent-continent collision and related large-scale tectonics in the region. The initial foredeep basin sequences are exposed in limited areas of the western Himalaya, which makes these areas very significant in unraveling the earliest evolution of the foreland system. The basal interval of the Himalayan foredeep is exposed in the Jammu area (India), which preserves silicified breccia formed by the erosion of hanging walls of shallow faults. Two Paleocene sections are analyzed that suggest the existence of growth faults which developed in response to the India-Asia collision in the Late Paleocene (∼57.9-54.7 Ma). The pebble-size clasts and their derivation entirely from the basement demonstrate rapid sedimentation in response to rapid subsidence at the onset of basin evolution. The angular unconformity showing effects of erosion associated with a thin soil horizon may be due to a forebulge at the site of the unconformity. The reworked bauxite above this soil horizon demonstrates erosion of another forebulge from the cratonward side. 相似文献
10.
Assessing tectonic and climatic causal mechanisms in foreland‐basin stratal architecture: insights from the Alborz Mountains,northern Iran 下载免费PDF全文
下载免费PDF全文 The southern foreland basin of the Alborz Mountains of northern Iran is characterized by an approximately 7.3‐km‐thick sequence of Miocene sedimentary rocks, constituting three basin‐wde coarsening‐upward units spanning a period of 106 years. We assess available magnetostratigraphy, paleoclimatic reconstructions, stratal architecture, records of depositional environments, and sediment‐provenance data to characterize the relationships between tectonically‐generated accommodation space (A) and sediment supply (S). Our analysis allows an inversion of the stratigraphy for particular forcing mechanisms, documenting causal relationships, and providing a basis to decipher the relative contributions of tectonics and climate (inferred changes in precipitation) in controlling sediment supply to the foreland basin. Specifically, A/S > 1, typical of each basal unit (17.5–16.0, 13.8–13.1 and 10.3–9.6 Ma), is associated with sharp facies retrogradation and reflects substantial tectonic subsidence. Within these time intervals, arid climatic conditions, changes in sediment provenance, and accelerated exhumation in the orogen suggest that sediment supply was most likely driven by high uplift rates. Conversely, A/S < 1 (13.8 and 13.8–11 Ma, units 1, and 2) reflects facies progradation during a sharp decline in tectonic subsidence caused by localized intra‐basinal uplift. During these time intervals, climate continued to be arid and exhumation active, suggesting that sediment supply was again controlled by tectonics. A/S < 1, at 11–10.3 Ma and 9‐6–7.6 Ma (and possibly 6.2; top of units 2 and 3), is also associated with two episodes of extensive progradation, but during wetter phases. The first episode appears to have been linked to a pulse in sediment supply driven by an increase in precipitation. The second episode reflects a balance between a climatically‐induced increase in sediment supply and a reduction of subsidence through the incorporation of the proximal foreland into the orogenic wedge. This in turn caused an expansion of the catchment and a consequent further increase in sediment supply. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
11.
发生在地球浅层的2008年汶川地震驱动了龙门山及前陆地区的地表同震垂向位移.根据冲断带-前陆盆地弹性挠曲模型理论,在进行弹性挠曲模拟反演的基础上,结合对深部地球物理特征(泊松比、电性结构)的分析,发现龙门山前陆盆地现今岩石圈有效弹性厚度(T_e)具有自东向西逐渐减薄的趋势,自川中地区的30~40 km减至龙门山地区的10~20 km.在对晚三叠世以来前陆盆地各阶段盆地结构进行刻画的基础上,进行弹性挠曲模拟反演,推断龙门山前陆盆地的前渊地区(四川盆地西部)岩石圈的T_e值自晚三叠世以来具有逐渐减薄的趋势.这可能与松潘一甘孜地块下方广泛存在的软流圈热物质对四川盆地西部岩石圈下部的长期加热而导致的熔融有关,反映了地球深部动力学过程与地球表层盆地演化之间的耦合关系. 相似文献
12.
本文对柴达木盆地东部新生代盆地结构和构造演化进行了研究.地震剖面揭示柴达木盆地东部新生界分别向南、北盆地边缘变薄和尖灭,盆地北部被欧龙布鲁克山和埃姆尼克山隆起强烈改造.通过对新生代地层厚度横向变化以及地层剖面分析,确定欧北断裂自中新世晚期开始向北逆冲,导致欧龙布鲁克山发生隆升和德令哈凹陷的形成.埃北断裂从上新世开始活动,与欧北断裂同时向北逆冲,导致德令哈凹陷进一步沉降,形成厚度达2600m的狮子沟组.埃南断裂在第四纪开始大规模向南逆冲,不仅造成其北侧的欧龙布鲁克山和埃姆尼克山隆起强烈抬升和向南推覆,而且导致南侧霍布逊凹陷的形成,成为柴达木盆地第四纪沉积中心.早期提出的前陆盆地和背驮式盆地模型显然不能解释柴达木盆地东部新生代构造格架和演化历史.本次研究认为柴达木盆地东部的形成是强烈的水平挤压作用导致地壳发生大规模褶皱的结果,即柴达木盆地东部新生代是一个大规模向斜.该向斜盆地模型很好地解释了新生代地层向盆地边缘减薄以及沉积中心主要位于盆地中部等现象.了解柴达木盆地东部构造发展对了解青藏高原侧向扩展具有重要意义. 相似文献
13.
Paleocene deep-water sediments and radiolarian faunas: Implications for evolution of Yarlung-Zangbo foreland basin, southern Tibet 总被引：10，自引：0，他引：10
丁林 《中国科学D辑(英文版)》2003,46(1)
Only a few Paleocene radiolarian assemblages have been reported, while the Early Paleocene zonal schemes remain poorly delineated. The Early Paleocene on-land radiolarians were described in the Hidaka melange belt of Japan and the North Island of New Zeal… 相似文献
14.
The southern Rif cordillera front, between Fes and Meknes, is formed by the Prerif Ridges, which constitute a thrust and fold belt, in contact with the Saïss foreland basin. Geological evidence and regional GPS network data support recent and active tectonics of this Alpine cordillera, with a top-to-the-S-SW motion with respect to stable Africa. A local non-permanent GPS network was installed in 2007 around Fes to constrain the present-day activity of the mountain front. Six GPS sites are located in the Prerif mountain front (jbel Thratt and jbel Zalarh), the Saïss basin and the foreland constituted by the tabular Middle Atlas. Measurements of the GPS network in 2007, 2009 and 2012, over a five year span, seem to indicate that this region is tectonically active and is subjected to significant horizontal motions: (i) a regional displacement toward the SW with respect to stable Africa, showing an average rate of 2 mm/yr; (ii) a southwestward convergent motion between the jbel Thratt with respect to the Saïss basin and the eastern Zalarh ridge, with an average rate of about 4 mm/yr; and (iii) moderate NNE–SSW divergent dextral motion between the Saïss basin and the northern front of the tabular Middle Atlas with an average rate of about 1–2 mm/yr. The regional southwestward motion is related to the activity of the NE–SW sinistral North Middle Atlas-Kert fault zone, which follows the Moroccan Hot Line. Convergence between the Prerif ridges, located at the southern edge of the Rif, and the Saïss basin is accommodated by ENE–WSW striking northward dipping reverse sinistral faults and south vergent folds. In addition, increasing deformation toward the western ridges is in agreement with the stepped mountain front and the development of the arched structures of the Prerif ridges. Normal faults located south of the Saïss basin are responsible for local extension. Whereas the most active deformation occurs in the southern front of the jbel Thratt near Fes, the Saïss foreland basin and the Middle Atlas foreland have only moderate to low tectonic activity, as evidenced by geological and GPS data. 相似文献
15.
We present an analysis of the consequences of foreland basin development on thinned continental lithosphere, inherited from pre-orogenic phases of extension. Bathymetry at the transition from pre-orogenic extensional basin to foreland basin and compaction of pre-orogenic sediments contribute to the accommodation space for foreland basin sediments and thrust loads. In addition, the extension-induced transient thermal state of the lithosphere, results in ongoing thermal subsidence, and a flexural rigidity which changes through time. Quantitative modelling of the phase of extension and the foreland basin stage of the Aquitaine basin (southern France) shows that the inherited transient thermal state of the lithosphere contributes significantly to (1) the total foreland basin depth and width, (2) the post-compressional subsidence history, and (3) the cratonward onlap pattern. Accounting for the thermo-mechanical effects of pre-orogenic extension significantly reduces the estimates of both the flexural rigidity (30–43% for the Aquitaine basin) and the required topographic or thrust load (40% for the Aquitaine basin) at foreland basins. Emplacement of thrust loads below sea level, as expected in a pre-orogenic extensional basin setting, further reduces the required topographic load. This sheds light on the wide range of flexural rigidity values reported for continental lithosphere from foreland basin modelling studies, and explains, in many instances, the inferred ‘hidden load’ or subsurface load in flexural modelling studies at foreland basins. The present study has shown that pre-orogenic extension phases significantly affect the record of vertical motion and the stratigraphy of the Aquitaine basin and is probably important for foreland basin evolution in general. 相似文献
16.
17.
Sedimentary deposits in the foreland basin of the northeastern Qilian Mountains are crucial documents recording tectonic activity and climate changes on the Tibetan Plateau. In this study, luminescence dating was used to date alluvial conglomerates and fluvial terrace sediments collected from the Beida River in the Jiuquan Basin, a foreland basin in the Hexi Corridor, northeastern Qilian Mountains. Detailed sedimentology and luminescence ages reveal that alluvial conglomerates accumulated from before 620 ka to 12 ka and that sediment accumulation rates increased at ∼330 ka and ∼35 ka, coinciding with the dates of two tectonic events (∼350 and ∼50 ka) and followed by climate cooling (from marine isotope stage (MIS) 9 to MIS 8 and from MIS 3 to MIS 2). This reveals that variations in the sediment accumulation rates are controlled by the coupling of tectonic uplift and climate cooling. The highest terrace (T7) that developed on the alluvial conglomerate base formed at ∼ 12 ka. The incision rate in the early Holocene was ∼2.1 mm/yr and increased to ∼14.6 mm/yr during the middle and late Holocene. The variations in the river incision rate provide geomorphic evidence for Holocene climate patterns in arid and semiarid areas. Luminescence dating offers a credible temporal framework for the deposits and reveals climate and tectonic effects on the evolution of the foreland basin, northeastern Qilian Mountains. 相似文献
18.
潮汕坳陷MZ-1井揭示的中生界为深入分析南海北部晚中生代的构造演化提供了关键性的资料.基于MZ-1井的标定,开展了系统的地震剖面构造-地层解释,在中生代地层内识别出Tm30区域性不整合面,同位素定年确定该界面发育于早白垩世末至晚白垩世初,落实了潮汕坳陷上白垩统的分布.此外,在研究区西南部识别出大型的兴宁—东沙逆冲推覆带,主要由多条NW—SE向延伸、西倾的叠瓦状逆冲断层及其伴生的不对称褶皱组成,其明显控制了上白垩统厚度分布.由此可见,上白垩统构造层不具有张裂盆地的典型特征,因此南海北部主动陆缘向被动陆缘的转换不会早于晚白垩世末.研究认为,在南海地区特提斯残留洋盆关闭的总背景下,在约80 Ma时期,南海地块与华南陆块强烈碰撞挤压,在靠近碰撞带处的礼乐滩、潮汕坳陷西南部形成褶皱冲断构造体系,进而控制了潮汕坳陷晚白垩世周缘前陆盆地的发育. 相似文献
19.
结合塔里木库车前陆盆地的109口井的地温数据，给出了库车盆地的地温场分布特征. 库车盆地各构造单元的平均地温梯度值为18～28℃/km，与我国其他大、中型沉积盆地相比，仍然偏低. 库车前陆盆地整体上是属于低温冷盆，山前带部位，依奇克里克、克拉苏和大宛齐等构造分区是低温冷盆中的高地温梯度带；从山前带由北向南，地温梯度逐渐降低. 在盆地的南部，地温梯度又存在明显差异. 总体上，地温梯度随深度的增加而降低，趋于一致，但在不同地质构造条件下其变化的速率不同. 在此基础上，进一步探讨地温梯度与盆地形成和构造演化的关系以及油气勘探意义. 相似文献
20.
Lei SHAO Chuanlian LIU and Karl STATTEGGER Laboratory of Marine Geology Tongji University Shanghai China E-mail: lshaok@online.sh.cn Institute of Geoscience University of Kiel Germany 《国际泥沙研究》2001,16(4)
1 INTRODUCnONThe comPonents of terrigenous sedimenop rocks indicate not only provenance information, but alsotoctOnic evolution of basin. The chdrical composition of the soure rOCks is probaby the major conttDon the chendstry of sedimentny rocks although this can be greaily modified by subsequent Processes(Rollinson l993). Thus, through exndning Petrological and chendcal comPosihons of tenigenoussedlinmp rocks, the comPonentS of the provenance or somee rOCks - which are conunnly a fun… 相似文献