共查询到20条相似文献，搜索用时 46 毫秒
1.
ZHANG Kexin HUANG Jichun YIN Hongfu WANG Guocan WANG Yongbiao FENG Qinglai TIAN Jun 《中国科学D辑(英文版)》2000,43(4)
The main character of melange strata in an orogenic belt is the integration of mixed materials due to the superposition, displacement or loss of various tectonic slices (blocks) of different origins and environments, different scales, different grades of deformation and metamorphism, and different stages of tectonic evolution. The approach to non-Smith strata in an orogenic belt is to focus on the understanding of the age, facies, tectonic setting of the original formation and the process of deformation-metamorphism of each tectonic slice, reconstruct the history of dispersal and integration of these tectonic slices in time and space, i.e. 4-dimensional. This paper studies the age and facies of the original formation of tectonic slices in the A'nyêmaqên melange belt based on new data of radiolarians, sporo-pollen and trace fossils, and cast new lights on the research of the evolution process of that belt. 相似文献
2.
ZHANG Guowei Dong Yunpeng Lai Shaocong GUO anlin Meng Qingren Liu Shaofeng CHENG Shunyou Yao Anping ZHANG Zongqing PEI Xianzhi Li Sanzhong 《中国科学D辑(英文版)》2004,47(4)
The Mianlue tectonic zone (Mianlue zone), an ancient suture zone in addition to theShangdan suture in the Qinling-Dabie orogenic belt, marks an important tectonic division geo-logically separating north from south and connecting east with west in China continent. To de-termine present structural geometry and kinematics in the Mianlue tectonic zone and to recon-struct the formation and evolution history involving plate subduction and collision in theQinling-Dabie orogenic belt, through a multidisciplinary study, are significant for exploring themountain-building orogenesis of the central orogenic system and the entire process of the majorChinese continental amalgamation during the Indosinian. 相似文献
3.
Timing of the intermediate-basic igneous rocks developed in the area of Kuhai-A’nyêmaqên along the southern east Kunlun tectonic belt is a controversial issue. This paper presents new zircon SHRIMP U-Pb dating data for igneous zircons from the Kuhai gabbro and the Dur’ngoi diorite in the Kuhai-A’nyemaqen tectonic belt, which are 555±9 Ma and 493±6 Ma, respectively. The trace element geochemical features of the Kuhai gabbro and the Dur’ngoi diorite are similar to those of ocean island basalts (OIB) and island arc basalts (IAB), respectively. Thus, the Kuhai gabbro with the age of 555±9 Ma and OIB geochemical features is similar to the Yushigou oceanic ophiolite in the North Qilian orogen, whereas the Dur’ngoi diorite with the age of 493±6 Ma and IAB geochemical features is similar to the island arc volcanic rocks developed in the north Qaidam. The Late Neoproterozoic to Early Ordovician ophiolite complex in the area of Kuhai-A’nyêmaqên suggests that the southern margin of the “Qilian-Qaidam-Kunlun” archipelagic ocean in this period was located in the southern east Kunlun tectonic belt. Therefore, the southern east Kunlun tectonic belt in the early Paleozoic is not comparable to the Mianlüe tectonic belt in the Qinling orogenic belt.
相似文献4.
《中国科学D辑(英文版)》2004,(4)
The Mianle tectonic zone, defined as a series of fault zones consisting mainly of south-verging thrusts and nappes, represents the south boundary of the Qinling-Dabie orogenic belt. The north side of the eastern end of the Mianle tectonic zone adjoins the exposure of the Dabieshan UHP rocks. Further to east, the zone was offset by the Tanlu faults and moved to eastern Shandong Province. While to its west, across the Qinghai-Tibetan Plateau, the zone was dislocated by the Altun fault, and… 相似文献
5.
6.
库尔勒—吉木萨尔剖面横跨塔里木盆地北缘、天山造山带和准噶尔盆地南缘.沿剖面完成了重磁联合反演,获得了岩石圈二维密度结构与二维磁性结构.结果发现,塔里木盆地与准噶尔盆地向天山造山带对冲.在地壳范围内,塔里木盆地北缘与准噶尔盆地南缘的平均密度较高,天山造山带的地壳平均密度较低.天山造山带具有较高的磁化强度,尤其表现在准噶尔盆地南缘至天山造山带中部的整个地壳范围内,预示着天山南北可能具有不同的构造演化历史、构造运动方式以及构造运动强度.在塔里木盆地与天山造山带以及准噶尔盆地与天山造山带的接触部位的上地幔顶部分别发现了低密度体,推测在塔里木盆地由南而北向天山造山带“层间插入与俯冲消减”,以及准噶尔盆地由北而南向天山造山带俯冲的过程中塔里木盆地北缘和准噶尔盆地南缘下地壳物质被带进天山造山带上地幔顶部.库尔勒—吉木萨尔剖面岩石圈二维密度结构与磁性结构为天山造山带的构造分段提供了岩石圈尺度的依据. 相似文献
7.
To reconstruct the cooling process of compound granites in different units (phases) with Laoshan Granitoid as an example, the relationships between formation, emplacement of I-A type granitoid and variation in tectonic environment and uplift of the orogenic belt are discussed from the viewpoint of thermal evolution. Now it has been pointed out that the cooling rates presented by the whole spectral series from I-type to A-type granites tend to be gradually faster and faster. Probably, it is a token of thermal evolution that the regional structural environment of the granites was converted from closed, compressive into open, tensile environment. 相似文献
8.
秦岭造山带与其南北两侧华北克拉通和扬子克拉通属三大构造单元,不论其各构造单元体还是其界带构造均甚为复杂,并受到多期次构造运动的制约,形成了大陆内部特异的造山过程.尽管在这一地域曾做过大量的地表地质工作和一些相关的地球物理工作,但对其壳、幔精细结构、深层动力过程,特别是同步穿越华北克拉通、秦岭-大巴造山带和扬子克拉通系统的耦合研究甚少.为了研究和探索该地域的壳、幔精细速度结构和其形成的深层过程,专门布置了一条北起榆林,向南经咸阳、宁陕直抵涪陵长达1000 km的高精度地震宽角反射、折射波场探测剖面.通过剖面辖区高分辨率的数据采集,数据处理、反演和壳、幔层、块精细速度结构,发现剖面辖区深部壳、幔结构存在特异的速度和结构变化,并厘定了一系列的新认识.研究结果表明:(1)秦岭—大巴造山带具有同一基底,其形成乃为结晶基底隆升所致,即它的形成仅涉及到上地壳的受力变形和空间状态.造山带与其南、北两侧的前陆盆地为陆内造山过程中同一深层过程的产物,但其沉积速率和形态却不相同.华北克拉通与秦岭造山带之间前陆盆地Bfc拉张为该区Moho界面的局部隆升所致.(2)首次提出了沿1000 km长剖面连续的沉积建造、结晶基底、上地壳、下地壳和上地幔顶部的层、块速度结构和各界面的起伏变化与空间状态.基于地震波边界场响应厘定了华北克拉通、秦岭—大巴造山带和扬子克拉通的分区界带.论述了三大构造单元各自的内部结构和其相邻界域的速度变化特征.(3)该区大陆内部速度结构和不同类型断裂分布及层序在华北克拉通、秦岭—大巴造山带、扬子克拉通三大块体地域存在显著差异.不同规模、层次与产状的断裂分布反映出它们在变形行为和机制上及所受构造运动的制约上均存在明显的差异. 相似文献
9.
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
10.
Geometry,kinematics and evolution of the Tongbai orogenic belt 总被引：2，自引：0，他引：2
1 Introduction spectively[2,3]. Several tectonic units such as the Bei- The Qinling-Dabie orogenic belt has attracted huaiyang, north Dabie, south Dabie and Susong belts worldwide attention by its very complex and abundant have been recognized in eastern Dabie[4]. Nine tec- geological characters, and has been a “hot point” of tonic units have been recognized in western Dabie and international geological research[1]. A vast amount of a more detailed division has been suggested especially … 相似文献
11.
12.
13.
Stefano Zanchetta Paolo D’Adda Andrea Zanchi Valentina Barberini Igor M. Villa 《Journal of Geodynamics》2011
The integration of structural analyses with 40Ar/39Ar dating of fault-related pseudotachylytes provides time constraints for the reconstruction of the Alpine evolution of the central portion of the South Alpine orogenic wedge. In the northern sector of the belt a Variscan basement is stacked southward on the Permian to Mesozoic cover along regional faults (Orobic and Porcile thrusts). Fault zones, slightly postdating a first folding event of Alpine age, experienced a complex evolution through the ductile and brittle deformation regime, showing greenschist facies mylonites overprinted by a penetrative cataclastic deformation. Generation of fault-related pseudotachylyte veins marks the onset of brittle conditions, lasting up to the youngest episodes of fault activity. 40Ar/39Ar dating of the pseudotachylyte matrix of 9 samples give two separated age clusters: Late Cretaceous (80–68 Ma) and latest Palaeocene to Middle Eocene (55–43 Ma). These new data provide evidence that the pre-Adamello evolution of the central Southern Alps was characterised by the superposition of different tectonic events accompanying the exhumation of the deepest part of the belt through the brittle–ductile transition. The oldest pseudotachylyte ages demonstrate that south-verging regional thrusting in the central Southern Alps was already active during the Late Cretaceous, concurrently with the development of a synorogenic foredeep basin where the Upper Cretaceous Lombardian Flysch was deposited. 相似文献
14.
本文对跨过西秦岭造山带(中段)的阿坝—若尔盖—临潭—兰州大地电磁剖面(WQL-L1)所采集到的数据进行了精细化处理分析和二维反演研究,结合跨过2013年岷县漳县地震区的WQL-L6剖面大地电磁探测结果和以往的地质与地球物理资料,对西秦岭造山带(中段)的深部电性结构、主要断裂带延伸状况以及与南北两侧地块的接触关系等进行了分析研究,结果表明:东昆仑断裂带塔藏段、迭部—白龙江断裂和光盖山—迭山断裂带共同组成了东昆仑断裂系统,分隔了松潘—甘孜地块和西秦岭造山带(中段);西秦岭北缘断裂带为主要的高角度南倾大型电性边界带,延伸深度穿过莫霍面;临潭—宕昌断裂带具有电性边界带特征,其延伸情况具有东、西差异.西秦岭造山带(中段)自地表到深度约20km范围表现为东北和西南浅、中部深的倒"梯形"高阻层,在高阻层之下广泛发育低阻层,低阻层与高阻层相互契合,呈现相互挤压堆积的式样,其西南侧的松潘—甘孜地块中下地壳存在西南深、东北浅低阻层,其东北侧的陇西盆地具有稳定的成层性结构,显示出西秦岭造山带(中段)正处于松潘—甘孜地块向北挤压和陇西盆地向南的阻挡挤压作用中.松潘—甘孜地块从西南向东北推挤、东北侧陇西盆地相对阻挡的相互作用是2013年岷县漳县6.6级地震发生的外部动力学机制,同时地震震源区特殊介质属性是该次地震发生的内部因素.西秦岭造山带(中段)中上地壳倒"梯形"高阻体埋深西薄、东厚的分段差异与该段内部中强地震分布差异有关.东昆仑断裂玛沁段和塔藏段内部的深部电性结构差异和延伸状况与东昆仑断裂自西向东走滑速率减小有内在联系. 相似文献
15.
通过对汶川地震前观测的碌曲—若尔盖—北川—中江大地电磁剖面的数据处理和反演解释,揭示了沿剖面的松潘—甘孜地块、川西前陆盆地、龙门山构造带及秦岭构造带50 km深度的电性结构特征及相互关系,表明青藏高原东缘向东挤压,迫使向东流动的地壳物质沿高原东缘堆积,并向扬子陆块逆冲推覆.龙门山恰好位于松潘—甘孜地块与扬子陆块对挤部位,主要受松潘—甘孜地块壳内高导层滑脱和四川盆地基底高阻体阻挡的约束,地壳深部存在着西倾且连续展布的壳内低阻层,表明龙门山深部确实存在着逆冲推覆构造,其逆冲断裂系中的三条断裂不仅以不同的倾角向西北倾斜,并且向深部逐渐汇集,但茂县—汶川断裂可能在深部与北川—映秀断裂是分离的.龙门山两翼的四川盆地和松潘甘孜褶皱带的电性结构既具有明显差异性,又具有一定的相关性.四川盆地显示巨厚的低阻沉积盖层和连续稳定的高阻基底的二元电性结构,而松潘—甘孜地块则表现为反向二元结构,即上部大套高阻褶皱带,下部整体为低阻的变化带,龙门山逆冲构造带本身又表现为松潘地块逆冲上覆在四川盆地之上,构成上部高阻褶皱带、中部低阻逆冲断裂带和底部盆地高阻基底的三层电性结构.对比龙门山逆冲构造断裂带的西倾延伸上下盘两侧的两个反对称的二元电性结构,松潘区块深部推断的结晶基底与龙门山断裂带下盘推断的下伏盆地结晶基底又存在某种内在对应关系,推断可能存在一个西延至若尔盖地块的泛扬子陆块.因此,龙门山构造带地壳电性结构研究对于揭示青藏高原东缘陆内造山动力过程,探索汶川大地震的深部生成机理都具有重要意义. 相似文献
16.
南海南部海域油气资源丰富,由于盆地沉积厚度大、沉积相横向变化快和构造演化复杂等原因,致使该海域新生代地层的划分方案差异大,地层时代的认识也存在较大分歧,这极大地制约了对盆地油气资源评价的正确认识.本文在总结国内外不同分层方案基础上,通过收集国外在南海南部深水区两口关键钻井的资料,开展曾母和北康两盆地重处理二维地震剖面的构造-地层解译,以及联井剖面的井震对比,重新识别和标定新生代重要构造变革面的地震反射特征.根据海域钻井、地层岩性、沉积环境、构造应力体系和古生物资料的综合对比研究,结合婆罗洲陆地测年结果和区域构造事件,重新厘定中中新世T3构造变革面的发育时代,年龄为15～17 Ma,分析了该界面的构造含义,认为其是南海海底扩张停止的一个构造响应界面,在南海南部海域对应南沙运动,在北婆罗洲地区表现为沙巴造山运动. 相似文献
17.
A REVIEW OF MOUNTAIN-BASIN COUPLING OF JIANGHAN AND DONGTING BASINS WITH THEIR SURROUNDING MOUNTAINS
Sedimentary basin and orogenic belt are two important components of continental structure with internal genetic links. The study of the basin-mountain coupling can reconstruct and restore the coupling relationships between the deep lithosphere process, near-surface structure and climate change over time. The Jianghan-Dongting Basin locates in the middle reaches of the Yangtze River, presenting a clear basin and mountain boundary with the Qinling-Dabie Shan to the north, the Mufu Shan to the southeast, the Wuling Shan to the southwest, and the E'xi Mountain to the west, respectively.
The Meso-Cenozoic Jianghan-Dongting Basin was affected by the subduction and collision of the Pacific plate and the Indian Ocean plate on the Eurasian continent, resulting in multiple tectonic evolution processes. There are some big rivers pouring into the Jianghan-Dongting Basin, such as the Yangtze River, Hanjiang River, Ba River, Xiangjiang River, and Yuanjiang River, etc. to serve as the material transport belts linking between the orogenic belt denudation and basin deposition. Therefore, the Jianghan-Dongting Basin has become a multi-source sedimentary basin, which makes it a natural laboratory to explore the geological processes from source to sink. Because the low-temperature thermochronology(e.g. fission-track and(U-Th)/He)can record the recent uplift time of mountains, they are widely used on the bedrock samples and the detrital synorogenic sediments in basins to constrain the surface uplift time of the orogenic belt. Hence, in the first parts of the paper we summarize and sort out the research results of basin-mountain coupling process in the Jianghan-Dongting Basin, evaluate the research results, identify the existing problems, and propose new research directions. After that, we introduce the applications of low-temperature thermochronology on the bedrock within the orogenic belt, basin and river sediments, combined with the actual situation of Jianghan-Dongting Basin, and put forward a new research breakthrough point. It is found that the Jianghan-Dongting Basin is very suitable for the study of low-temperature thermalchronology on detrital minerals. However, it should combine the low-temperature thermochronology results of both orogenic belt and river sediments with the provenance analysis on the same target minerals, building the connection between the exhumation and provenance information on the orogenic belt, thus providing the detailed evolution of mountain-basin coupling process. 相似文献
18.
陕西省数字地震台下方壳幔速度结构研究 总被引：3，自引：1，他引：3
利用广义反、透射系数的传递矩阵计算理论地震图，用快速模拟退火法搜索最佳模型，通过与地震台站实际记录的P波波形进行拟合对比，反演了陕西省13个数字地震台下方的P波速度结构。台站分布区域涉及到秦岭造山带、渭河盆地及鄂尔多斯地台三个构造区域。结果显示，3个构造区的地下速度结构差异明显，呈现了各自的构造特点。其中秦岭造山带上地壳乃至地表速度高，中下地壳出现多个低速层，可能与岩石脱水、构造滑脱带等有关；渭河盆地内上中地壳高低速度层交替出现，反映了断层活动在浅部的影响；鄂尔多斯地台有部分台站保持稳定的匀速构造。反映了古老地台地层稳定发展的特性，部分台站受到后期改造，低速层位增多。因为变化剧烈的台站分布在盆地的南部和西部。而且震源机制解显示该区主应力场方向为近东西向，可以说秦岭北缘的断裂作用以及后来来自青藏高原的挤压应力是导致渭河盆地形成和发展的主要因素。最后我们讨论了速度结构与强震、地震分布以及不同构造演化的关系。 相似文献
19.
阴山造山带位于鄂尔多斯盆地的北缘,这一地带不仅是构造活动强、弱的变异地域,且为盆、山的耦合地带,故在造山带与盆地地域具有各异的深层动力过程.本文基于高精度人工源地震宽角反射、折射探测和高分辨率的数据采集,通过反演求得了满都拉—鄂尔多斯—榆林—延川长达650 km剖面辖区的岩石圈精细层、块结构.研究结果表明：①沿该剖面由南向北地壳厚度为40~45 km;在不同构造单元其介质、结构均不相同;速度分布、空间结构形态和界面起伏及属性亦存在着明显差异;上地幔顶部速度为8.0~8.1 km/s;②沿剖面存在5条深、大断裂,且将该区切割成为壳、幔结构明显差异的4个构造单元,即鄂尔多斯盆地、盆山耦合地带、阴山造山带、内蒙构造带,它们各自具有固有的深层过程和动力学响应.同时厘定了阴山造山带与内蒙构造带之间的白云鄂博深、大断裂带是古亚洲洋的南界.在这里不仅导致了阴山造山带的形成,而且聚集了诸多的金属矿产资源,地震亦频繁活动.基于上述研究表明,阴山造山带—鄂尔多斯盆地耦合地带的壳、幔结构复杂、呈现出速度结构各异的层、块状展布.显然,在这一错综的成山、成盆、成岩、成矿和成灾地带,有着特异的深层过程和动力机制. 相似文献
20.
Metallogenesis of the Ertix gold belt, Xinjiang and its relationship to Central Asia-type orogenesis 总被引：11，自引：0，他引：11
The Ertix gold belt is located on the boundary of the Kalatongke arc and the Kelan back-arc basin of D-C1. Most scholars used
to interpret the formation and distribution of the gold deposits in the Ertix tectonic belt in terms of the petrogenic and
metallogenic models for active continental margins. However, enormous data of isotopic dating and geologic research show that
the mineralization was obviously later than the oceanic subduction, whereas exactly simultaneous with the collisional orogenesis
during C2-P, especially at the transition stage from collisional compression to extension. Based on study of metallogenic time, tectonic
background, ore geology, ore fluid nature, ore material source, etc., we reveal that all the gold deposits possess the character
of orogenic deposits formed in collisional orogenic system, and that their ore-forming materials mainly have derived from
the stratigraphic terranes south to individual deposits. Accordingly, the theoretical tectonic model for collisional metallogenesis
and petrogenesis is employed to explain the formation of the Ertix gold belt and to determine the gold exploration directions. 相似文献