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1.
文章探讨了塔里木盆地北缘和南天山造山带的盆-山耦合和构造转换过程。塔里木盆地属于典型的叠合盆地,经历了多期构造演化。研究表明,在地史时期中,塔里木盆地北缘和相邻南天山造山带经历了多期和复杂的盆山耦合和盆山转换过程,形成多种类型盆山耦合和转换方式。(1)按时间域可划分为:早古生代陆内裂陷盆地-早期伸展造山-晚期挤压造山耦合,晚古生代陆内裂陷盆地-弧后造山-晚期碰撞造山耦合,中生代陆内前陆盆地-挤压造山耦合,古近纪前陆盆地-挤压造山耦合,新近纪—第四纪再旋回前陆盆地-挤压造山耦合;(2)按深度域可划分为:深部地幔俯冲型盆-山耦合,地壳分层滑脱拆离型盆-山耦合,基底滑脱拆离型盆-山耦合,古生代伸展和逆冲推覆型盆-山耦合,中—新生代逆冲推覆型盆-山耦合;(3)按运动学和动力学可划分为:逆冲推覆型盆-山耦合和接触关系、重力滑脱型盆-山耦合和接触关系、走滑转换型盆山耦合和接触关系、深部岩浆上涌焊接型盆-山耦合和接触关系、鳄鱼嘴型盆-山耦合和接触关系。  相似文献   

2.
中国中西部中、新生代前陆盆地与挤压造山带耦合分析   总被引:69,自引:8,他引:61  
中国中西部主要由中、新生代造山带与中、新生代盆地构成盆山格局 :秦岭造山带与南北两侧四川盆地与鄂尔多斯盆地 ;天山造山带与南北两侧塔里木盆地与准噶尔盆地 ;哀牢山造山带与东西两侧楚雄盆地与兰坪思茅盆地等 ,总体上构成盆山耦合。根据挤压造山带类型与前陆盆地类型 ,可以划分出 3种耦合类型 ,即 ( 1)碰撞造山带与周缘前陆盆地 ,( 2 )俯冲造山带与弧后前陆盆地及 ( 3)再生造山带与再生前陆盆地。因此前陆盆地是伴随着造山带的形成与演化而发育 ,造山带断滑系统直接控制前陆盆地结构、沉积层序及构造样式等 ,从而制约前陆盆地油气分布的有序性  相似文献   

3.
论龙门山前陆盆地与龙门山造山带的耦合关系   总被引:11,自引:0,他引:11  
论龙门山前陆盆地与龙门山造山带的耦合关系李勇(成都理工学院沉积地质研究所,成都610059)关键词盆山耦合沉积响应地层标识造山作用成盆作用前陆盆地造山带大陆动力学是当今地球科学研究的前沿课题,造山带及其毗邻盆地是研究大陆构造的两个最重要的构造单元,因...  相似文献   

4.
摘 要  塔里木盆地北部边缘与南天山中、新生代构成了封闭的陆内盆 山系统。结合世界上 典型挤压造山带与前陆盆地关系研究的诸多成果‚采用校正的构造回剥曲线、时间段曲线‚ 平衡剖面等定量、半定量分析方法‚得出了研究区中、新生代陆内盆 山关系的演化过程及模 式。  相似文献   

5.
西昆仑—塔里木—天山岩石圈深地震探测综述   总被引:40,自引:6,他引:40  
高锐  高弘 《地质通报》2002,21(1):11-18,T001,T002
沿新疆地学断面走廊域实施了3种深地震探测方法:近垂直深地震反射剖面、宽角反射与折射深地震测深剖面和移动式宽频地震观测,揭露出西屁仑-塔里木-天山岩石圈的结构与横向变化,发现了塔里木大陆地块与青藏高原西北部西昆仑造山带碰撞的地震学证据,揭示出天山与塔里木、天山与准噶尔,以及昆仑山与塔里木之间的岩石圈尺度盆山耦合关系。阶段成果发表后引起国内外学者广泛注意,本文结合相关资料对这些新成果进行了系统综述,旨在对比研究青藏高原南北两缘不同的碰撞变形之深部过程。  相似文献   

6.
盆地和造山带是在空间展布和形成机制上具有密切联系的构造体系。盆 -山体系的构造样式分析 ,不仅可以重塑造山带及其邻区盆地的盆山耦合过程和景观演化 ,而且是探索造山作用对地貌、气候、资源、能源、环境和灾害等方面控制作用的基础。按照地球动力学环境 ,可以归纳为三种主要类型 ,即伸展、挤压、走滑盆 -山体系 ,结合其所处的大地构造体制和板块运动阶段 ,可以得出盆 -山体系构造样式的综合分类方案。长江流域的地质 -生态环境与自然灾害受到中新生代以来地壳运动和秦岭 -大别等造山作用的严格制约与影响。根据盆地原型和盆缘造山带之间的配置关系和成因联系 ,研究区长江流域中央造山系的典型盆 -山体系构造样式主要有桐柏 -大别造山带与中扬子北缘的江汉洞庭断陷盆地 ,秦巴边缘冲断造山带与上扬子北缘的四川前陆盆地。本文按同造山期、晚造山期和后造山期演化阶段 ,依此分析两个典型盆 -山体系的构造样式演化特征及其动力学机制探讨  相似文献   

7.
陆内挤压造山带与陆内前陆盆地关系   总被引:3,自引:0,他引:3  
张明山 《现代地质》1997,11(4):461-470
塔里木盆地北部边缘与南天山中,新生代构成了封闭的陆内盆-山系统。结合世界上典型挤压造山带与前陆 地关系研究的诸多成果,采用校正的构造回剥曲线,时间段曲线,平衡剖面等定量,半定量分析方法,得出了研究中,新生儿陆内盆-山关系的演化过程及模式。  相似文献   

8.
新疆阿尔泰造山带南缘包括额尔齐斯构造带,为重要金矿床成矿带之一.文章以研究区成矿地质背景及成矿特征为基础,应用金矿成矿过程中构造-流体-成矿作用理论,对阿尔泰造山带南缘金矿成矿规律进行分析和探讨,提出了阿尔泰造山带南缘山-盆转换系统内金的构造-流体-成矿作用体系中构造主导作用、流体直接作用及构造和流体耦合作用与金矿成矿机理和时空分布特征间的关系.  相似文献   

9.
王国灿  申添毅  陈超  季军良  王岸 《地球科学》2020,45(12):4313-4331
西北地区中-新生代以来发育系列断陷盆地,盆地内的覆盖层结构及其与周缘造山带之间的盆山构造地貌关系是研究大陆动力学的基础性问题.在覆盖区地质调查工作中,利用地质学、地球物理学、地球化学、钻探等多种方法手段,可以对覆盖区盆地的结构形态、盆地边界构造属性、沉积物分布特征、沉积过程的源汇体系进行系统的分析研究,帮助深入理解覆盖区的沉积过程、山脉隆升剥露过程以及构造地貌演化过程.基于新疆吐哈盆地覆盖区的地质调查工作,本研究提出并实践了在覆盖区开展盆山构造地貌关系研究的技术方法体系.通过野外地质调查和室内测试分析,结合重力、航磁、地震等地球物理勘探方法以及钻孔岩心分析,系统分析和探讨了哈密盆地中-新生代覆盖层三维结构、控盆控貌构造及源汇系统,建立了研究区与相邻造山带之间的盆山耦合关系及构造地貌演化过程,为覆盖区地质调查过程中开展盆山构造地貌过程的研究提供了示范.   相似文献   

10.
滇西三江地区中新生代“盆山”耦合运动学过程   总被引:3,自引:0,他引:3  
滇西三江地区中新生代盆山格局是研究盆山耦合的典型实例。本文通过解析该区叠加构造变形期次和样式,理清其中新生代的盆山耦合关系,并探讨思茅盆地对相邻造山演化的沉积响应过程。研究表明,三江地区经历了主碰撞造山带与前陆盆地耦合(T1-T2)、后碰撞造山带与伸展盆地耦合(T3-K)以及陆内"盆山"共变(E-Q)三个盆山耦合运动学过程。兰坪-盆地内复理石、山前磨拉石到红色碎屑岩的沉积序列响应了相邻造山带从主碰撞阶段向后碰撞阶段的演化,该阶段盆地转换过程受控于拆沉作用和岩浆底侵作用等深部动力学机制。  相似文献   

11.
填海工程使滨海地区的地下水物理化学条件改变,导致该区域地下水中重金属浓度升高。本文以深港西部通道填海区为例,采用实验室模拟填海条件的办法,初步探讨了影响填海区地下水重金属迁移的关键因素。模拟实验结果表明,填海区地下水中钨元素含量升高与地下水淡化、淤泥氧化过程以及填料风化有关;铜元素含量升高则与淤泥氧化过程以及填料风化有关;钒元素含量升高与地下水淡化和淤泥氧化过程有关,而其他元素含量升高则主要与填料风化释放有关。  相似文献   

12.
新疆维吾尔自治区阿图什市木吉地区邻近帕米尔,是印度板块与欧亚板块碰撞挤压应力最集中的地区,地层变质和变形强烈,研究基础薄弱。木吉群由变质砂岩、板岩、千枚岩、石英岩、钙质石英岩、变粒岩、二云石英片岩、大理岩等组成,一直未发现任何化石。最近,笔者在木吉乡的喀拉足克沟和阿拉木陶沟的粉砂岩、钙质粉砂岩中发现了一些植物管胞片和孢粉化石:Gran-ulatisporites sp.,Cycloranisporites sp.,Verrucosisporites sp.,Pityosporites sp.,Punetatosporites sp.,Leiotriletes sp.,Apicu-latisporites sp.,Platysaccus sp.,Cycodopites sp.等。从地层接触关系和孢粉化石的整体面貌看,木吉地区含上述孢粉化石的木吉群的时代可能为泥盆纪—石炭纪。  相似文献   

13.
Over the past decade researchers working on the rocks of the Beaufort Group in the main Karoo Basin of South Africa have vastly increased our understanding of this important Permo-Triassic sequence. Many new fossil forms have been discovered, allowing for breakthroughs into the biodiversity, biogeography and biostratigraphy of the group. Taxonomic and phylogenetic advances are many and varied, and cover most of the vertebrate taxa, but with emphasis placed on the temnospondyl amphibians, archosauriforms and non-mammalian synapsids, in particular the anomodontia. Biostratigraphic breakthroughs have centered on the Middle Permian Eodicynodon and Tapinocephalus assemblage zones, the Late Permian Dicynodon Assemblage Zone, and the Triassic Lystrosaurus and Cynognathus assemblage zones. Correlation of these biozones with better dated sequences in Europe, Russia and China has allowed for many chronostratigraphic refinements, which are in turn vital for sequence stratigraphical analysis of the basin fill. Based on fossil data, both the lower (Ecca–Beaufort) and upper (Beaufort–Molteno) contacts of the group have been proved to be highly diachronous. The refined chronostratigraphic framework has also allowed for a better analysis of the basin evolution through time, particularly in terms of the correlation of external stimuli that affect basin sedimentation patterns.  相似文献   

14.
藏北羌塘丁固—加措地区康托组的时代   总被引:2,自引:0,他引:2  
自西藏区域地质调查大队创建康托组以来,康托组岩石地层单位广泛应用于羌塘地区,普遍认为其时代为新近纪.笔者于丁固-加措地区的康托组地层中采获古近纪轮藻化石Obtusocharat sp.,O.lanpingenis,Gyrogona qinajiangica和部分孢粉化石,并在康托组底部安山岩中获K-Ar年龄65.1~66.5Ma.上述轮藻组合与同位素年龄指示的地层时代为古新世-始新世,据此将测区康托组的时代确定为古近纪.由于测区康托组之上被唢纳湖组或鱼鳞山组角度不整合覆盖,因此康托组时代的确定不仅进一步完善了测区新生代地层系统,还指示测区在康托组与唢纳湖组或鱼鳞山组之间发生了一次强烈的构造运动.  相似文献   

15.
西藏措勤县雄玛地区林子宗群帕那组火山岩大地构造位置位于冈底斯—念青唐古拉山板片,地层分区上属于冈底斯地层区、隆格尔—南木林地层分区。岩性主要为一套以浅灰色、灰绿色流纹质凝灰岩为主,夹浅黄绿色、灰绿色流纹岩及英安岩、火山角砾岩、杂砂岩及砾岩的岩石组合。之下与永珠组和拉嘎组呈喷发不整合接触。岩石地球化学特征表明该火山岩系属过铝质的高钾钙碱性—亚碱性系列,稀土元素地球化学中轻稀土元素明显富集,微量元素中大离子亲石元素(Rb、K、Th、U、LREE)富集,高场强元素(Nb、P、Ti)亏损。以上特征说明雄玛地区林子宗群帕那组火山岩岩浆源于陆壳重熔,属与俯冲造山有关的陆相火山岩,同时又兼具陆—陆碰撞的特点。推测帕那组火山岩形成于新特提斯洋壳俯冲基本结束,印度板块与欧亚板块碰撞开始的构造背景下,年龄大概在38Ma左右,为始新世晚期。  相似文献   

16.
Summary The Middle Proterozoic Faraday Metagabbro in the Bancroft area of eastern Ontario has been subjected to syn-orogenic textural and mineralogical modifications resulting in the formation of scapolite-bearing metagabbro and gabbroic blastomylonite assemblages. The elemental flux during cryptic and overt scapolitization has been calculated usingGresens general metasomatic equation which applies corrections for density and volume changes during alteration. Metasomatic variation diagrams using analyses from two primary gabbros and six altered rocks indicate that Na, K, Cl, Li, Rb, and Ba are the principal introduced elements and that Cu and S were removed. These changes are very similar to those involved in the formation of metasomatic nepheline-bearing rocks elsewhere in the district and, furthermore, nephelinization and scapolitization were broadly coincident in time and space. It is concluded that the nephelin- and scapolite-bearing rocks and their cryptic facies are different manifestations of the same metasomatic agent and that the source of the fluids was a possible horizon of evaporitic sediments within the country rocks in which the gabbro was emplaced.
Metasomatose im Faraday-Metagabbro, Bancroft, Ontario, Kanada
Zusammenfassung Der Mittel-proterozoische Faraday-Gabbro in der Umgebung von Bancroft (Ost-Ontario) erfuhr synorogene Veränderungen in Textur und Mineralogie, die zur Bildung skapolit-haltiger Metagabbros und gabbroider Blastomylonite führten. Die während kryptischer und offener Skapolitisierung stattfindende Elementtransport wurde mit Hilfe der vonGresens entwickelten generellen metasomatischen Gleichung errechnet; Korrekturen für Varänderungen in spezifischer Dichte und Volumen wurden angebracht. Metasomatische Variationsdiagramme basierend auf Analysen an zwei primären Gabbros und sechs modifizierten Gesteinen zeigen, daß Na, K, Cl, Li, Rb und Ba die hauptsächlich zugeführten Elemente darstellen, und daß Cu-und S-Konzentrationen abgebaut wurden. Diese Veränderungen sind vergleichbar mit solchen, wie sie bei der Bildung metasomatischer, Nephelin-haltiger Gesteine erkannt wurden. Außerdem fallen Nephelinisierung und Skapolitisierung zeitlich und räumlich in etwa zusammen. Daraus kann geschlossen werden, daß Nephelin- und Skapolit-haltige Gesteine und deren kryptische Phasen durch den gleichen metasomatischen Prozeß entstanden sind, und daß die Herkunft der umwandelnden Lösungen möglicherweise in evaporitischen Sedimenten zu suchen ist, in die der Gabbro intrudierte.


With 3 Figures  相似文献   

17.
The paper reports newly obtained data on the geochronology of the Dovyren intrusive complex and associated metarhyolites of the Inyaptuk Formation in the Synnyr Range. The data were obtained by local LA-ICPMS analysis of zircons in samples. The U-Pb age of olivine-free gabbronorite from near the roof of the Yoko-Dovyren Massif is 730 ± 6 Ma (MSWD = 1.7, n = 33, three samples) is close to the estimated age of 731 ± 4 Ma (MSWD = 1.3, n = 56, five samples) of a 200-m-thick sill beneath the pluton. These data overlap the age of recrystallized hornfels found within the massif (“charnockitoid”, 723 ± 7 Ma, MSWD = 0.12, n = 10) and a dike of sulfidated gabbronorite below the bottom of the massif (725 ± 8 Ma, MSWD = 2.0, n = 15). The estimates are also consistent with the age of albite hornfels (721 ± 6 Ma, MSWD = 0.78, n = 12), which was produced in a low-temperature contact metamorphic facies of the host rocks. The average age of the Dovyren Complex is 728.4 ± 3.4 Ma (MSWD = 1.8, n = 99) based on data on the sill, near-roof gabbronorite, and “charnockitoid”) and is roughly 55 Ma older than the estimate of 673 ± 22 Ma (Sm-Nd; [13]). The U-Pb system of zircon in two quartz metaporphyre samples from the bottom portion of the Inyaptuk volcanic formation in the northeastern part of the Yoko-Dovyren Massif turns out to be disturbed. The scatter of the data points can be explained by the effect of two discrete events. The age of the first zircon population is then 729 ± 14 Ma (MSWD = 0.74, n = 8), and that of the second population is 667 ± 14 Ma (MSWD = 1.9, n = 13). The older value pertains to intrusive rocks of Dovyren, and the age of the “rejuvenated” zircon grains corresponds to the hydrothermal-metasomatic processes, which affected the whole volcano-plutonic sequence and involved the serpentinization of the hyperbasites. This is validated by the results of Rb-Sr isotopic studies with the partial acid leaching of two serpentinized peridotite samples from the Verblyud Sill. These studies date the overprinted processes at 659 ± 5 Ma (MSWD = 1.3, n = 3).  相似文献   

18.
The Kaalamo massif is located in the Northern Ladoga region, Karelia, on the extension of the Kotalahti Belt of Ni-bearing ultramafic intrusions in Finland. The massif, 1.89 Ga in age, is differentiated from pyroxenite to diorite. Nickel–copper sulfide mineralization with platinoids is related to the pyroxenite phase. The ore consists of two mineral types: (i) pentlandite–chalcopyrite–pyrrhotite and (ii) chalcopyrite, both enriched in PGE. Pd and Pt bismuthotellurides, as well as Pd and Pt tellurobismuthides, are represented by the following mineral species: kotulskite, sobolevskite, merenskyite, michenerite, moncheite, keithconnite, telluropalladinite; Pt and Pd sulfides comprise vysotskite, cooperite, braggite, palladium pentlandite, and some other rare phases. High-palladium minerals are contained in pentlandite–chalcopyrite–pyrrhotite ore. Native gold intergrown with kotulskite commonly contains microinclusions (1–3 μm) of Pd stannides: paolovite and atokite. Ore with 20–60% copper sulfides (0.2–6.0% Cu) contains 5.1–6.6 gpt PGE and up to 0.13–2.3 gpt Au. Pd minerals, arsenides and sulfoarsenides of Pt, Rh, Ir, Os, and Ru are identified as well. These are sperrylite, ruthenium platarsite, hollingworthite, and irarsite; silvery gold and paolovite have also been noted. All these minerals have been revealed in the massif for the first time. The paper also presents data on the compositions of 25 PGE minerals (PGM) from Kaalamo ores.  相似文献   

19.
海南大坡岩体位于五指山褶皱带内,主要受昌江—琼海构造带、琼西构造带与潭爷断陷构造带控制.岩石地球化学及岩石学研究表明,大坡岩体形成于海西-印支晚期,岩性单一,主要为中细粒似斑状黑云母二长花岗岩.岩体显示为Ⅰ型花岗岩与S型花岗岩的混合,主体以地壳物质部分熔融为主,形成过程有少量地幔物质加入.元素对的比值及稀土元素配分特征说明岩体钨锡等多金属含矿性可能较差.  相似文献   

20.
Remote sensing data and GIS techniques have been used to compute runoff and soil erosion in the catchment area along the NH-1A between Udhampur and Kud covering an area of approximately 181 km2. Different thematic layers, for example lithology, a landuse and landcover map, geomorphology, a slope map, and a soil-texture map, were generated from these input data. By use of the US Soil Conservation Service curve number method, estimated runoff potential was classified into five levels—very low, low, moderate, high, and very high. Data integration was performed by use of the weighting rating technique, a conventional qualitative method, to give a runoff potential index value. The runoff potential index values were used to delineate the runoff potential zones, namely low, moderate, high, and very high. Annual spatial soil loss estimation was computed using the Morgan–Morgan–Finney mathematical model in conjunction with remote sensing data and GIS techniques. Greater soil erosion was found to occur in the northwestern part of the catchment area. When average soil loss from the catchment area was calculated it was found that a maximum average soil loss of more than 20 t ha−1 occurred in 31 km2 of the catchment area.  相似文献   

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