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1.
地体构造对金区域成矿的重要意义   总被引:3,自引:0,他引:3  
地体构造学是板块构造的发展和初充,几乎所有的地台(克拉通),造山带,大陆板块皆是由独立的地体所构成。相邻地体可由地质特征和区域成矿规律上的不同及边界断裂来鉴别。近二十年来,对于金等矿床区域成矿规律的研究,发现华北地台(NCP)和中国东部造山带中金矿的分布与地体构造密切相关。富金地体与盆金地体有明显不同,它们在基底的组成,岩浆作用,交代蚀变作用,构造环境和演化历史方面形成明显的对照。富金地体经常位于地台的边缘与造山带相邻以及位于A型或B型储冲带的上盘,在结晶基底中常有两绿岩带,多时期花岗岩和富挥发分,富大离子亲石元素和富Au的煌斑岩广泛分布。贫金地体常与此相反。  相似文献   

2.
山东半岛的地体构造及金矿成矿的区域地质背景   总被引:5,自引:0,他引:5  
卢冰  胡受奚 《地质论评》1995,41(1):7-14
本文以不整合面的发现及同位素年龄为依据,重新厘定了本区早前寒武纪的地层,从而搞清了本区的大地构造格架,认为它类似于加拿大地盾的“洋葱构造”。本文将山东半岛划分为4个地体:胶北地体,鲁西地体,胶南地体,胶东南-苏东北-黄海地体。认为胶北地体成矿的大地构造背景与南克拉通成矿背景十分相似。胶南地体,黄海地体对胶北地体的俯冲作用为胶北地体提供了成岩成矿物质。根据胶北群和齐山群的地质及及地球化学特征,认为胶  相似文献   

3.
造山带的网结状构造样式   总被引:4,自引:0,他引:4  
网结状构造样式是造山带地壳结构的一个重要特征,表现为线状强应变带与夹持其间的透镜状弱应变域规律组合格式。这种网结状型式在几何学上具有尺度不变性,并具三维特征,理论分析和实际观察指出,这种网结状构造样式,是在应变软化作用及变形分解作用控制下递进发育而成的,而造山带地壳结构的不均一性、组成造山带岩石的流变学特征以及变形物理环境,又是控制应变软化及变形分解作用的主要因素。  相似文献   

4.
从板块构造到地体   总被引:4,自引:0,他引:4  
从板块构造的发生、发展到地体概念的提出,论述了地体解析和拼贴构造,并根据中国东部的地体研究,特别是中国东北那丹哈达地体和日本美浓地体的对比研究,论述了亚洲东部中生代构造发展史,认为在侏罗纪时,亚洲大陆边缘的地体拼贴活动已经开始,形成了拼贴沉积的复合地体;白垩纪时由于大陆边缘的侧向挤压和离散作用,这些地体产生左行运动和变形;早第三纪晚期由于日本海的扩张,形成了弧形的日本列岛。  相似文献   

5.
中国东南大陆岩石圈演化研究中的有关问题刍议   总被引:5,自引:1,他引:4  
本文依据大地构造理论和最新研究资料对中国东南大陆岩石圈演化研究中的有关问题作了探讨,认为地体理论和大地构造相模式理论是相辅相成的;建议扬弃华夏古、特提斯构造域和太平洋构造域等可能束缚研究思路的概念;将板片构造、斜向碰撞与走滑纳入中国东南部碰撞造山带的研究内容。  相似文献   

6.
中国东南大陆岩石圈演化研究中的有关问题雏议   总被引:5,自引:1,他引:5  
本文依据大地构造理论和最新研究资料对中国东南大陆岩石圈演化研究中的有关问题作了探讨,认为地体理论和大地构造相模式理论是相辅相成的;建议扬弃华夏古陆、特提斯构造域和太平洋构造域等可能束缚研究思路的概念;将板片构造、斜向碰撞与走滑纳入中国东南部碰撞造山带的研究内容  相似文献   

7.
内蒙古中部早古生代地体的拼合与增置   总被引:5,自引:0,他引:5  
内蒙古中部布龙山、温都尔庙一带的蛇绿岩套、蓝门石片岩及其南邻的华北地台两者在空间上以川井-布鲁台庙深大断裂带为界,在时间上具有截然不同的地质演化特点。其内部在构造演化史上也不尽相同,可进一步划分为布龙山-哈拉地层地体和白乃庙-温都尔庙混杂地体。这两个曾分离着的地体,经长时期的运移,于晚志留世之前拼合联为一体,构成早古生代联合地体。直到早二叠世才增置于中朝古板块北缘(或华北地台北缘)。  相似文献   

8.
<正> 本文涉及的中上元古宇包括下寒武统之下,吕梁运动面(即相当于长城系底面)以上的一套地层。中、晚元古宙的沉积在我国东部分布较广,在不同的小区内,在沉积建造和地层序列上常显示出各自的特色。可按沉积时限、地壳构造活动性、沉积物特征和生物群面貌将东部中上元古宇分为四种沉积类型,简称蓟县型、旅大型、扬子型和江南型,名称来源于代表性剖面所在地或沉积区的地名。  相似文献   

9.
地体构造对研究地台和地盾区域成矿规律的重要性   总被引:3,自引:0,他引:3  
30年前板块构造理论的建立引起所有相关的地球科学的革命,其中包括区域成矿学。然而随着地球科学理论的发展,板块构造理论对于解释地壳,特别是早前寒武的地盾、地台和克拉通区的复杂构造现象显得不完备,因此,近20年来地体构造理论的发展补充了板块构造理论的不足。近年来,各国地质学家相继发现世界上各地盾、地台和克拉通区,如华北地台、乌克兰地盾、阿尔丹地盾、加拿大地盾、非洲地台、澳大利亚耶尔冈克拉通等是由多个地体所组成。每一个地体是一个独立的和基本的地质构造单元,彼此间由地缝合线或深断裂隔开。由于每个地体的地质特征、构造环境和成矿作用各不相同,因而地体构造成为区域成矿学的一个重要组成部分。  相似文献   

10.
新疆北部古生代大陆增生构造   总被引:35,自引:2,他引:35  
古生代亚洲中部是一幅两陆夹一洋、洋中多地体的构造图案,大地构造框架与现代西南太平洋格局十分相似。中亚造山带是晚古生代复杂地体的拼贴带。新疆北部古生代存在4类成因的8个地体构造。它们以裂解陆块地层块体、海山和火山弧的形式散布在中蒙大洋中,诸地体间是一系列的小洋盆。晚古生代,这些地体开始彼此拼贴并导致强烈推覆作用。石炭纪末-二叠纪初,中蒙大洋闭合,散布其中的诸地体分别增生到塔里木大陆北缘和西伯利亚大陆南缘。北天山-准噶尔地区6条蛇绿岩带记录了诸地体间碰撞事件。  相似文献   

11.
大别山前寒武纪变质地体基本组成   总被引:5,自引:0,他引:5  
桑隆康  游振东 《地质论评》1994,40(3):265-273
本文以新城-圻春断裂为界将大别山前寒武纪变质地体划分为华北陆块南缘和场子陆块北缘两个次级变质地体,两个次级地体不仅在地球物理,构造变形方面明显不同,而且在物质成分上有显著差异,它们有各自独立的变质地层系统,遭受了不同类型的变质作用,有完全不同的岩浆活动图象,上述差异均可指示华北,扬子两古陆碰掸对接时扬子陆块北缘向北俯冲至华北陆块南缘之下,这可能包括两次合作用,从元古代开始至中生代最终结束的长期复杂  相似文献   

12.
青藏高原主要地体地壳短缩作用研究现状及存在的问题   总被引:1,自引:0,他引:1  
在对喜马拉雅、拉萨和羌塘3个地体已有的有关地壳短缩研究成果系统分析的基础上,对3个地体进行了平衡剖面恢复:北羌塘侏罗系短缩率为25.18%.南羌塘短缩率为33.57%;对拉萨地体南段(措勤盆地南部坳褶带)上白垩统恢复得出其短缩率为20.68%北段中部坳褶带到班公湖一怒江缝合带南缘短缩率为25.3%;地处特提斯喜马拉雅地体东段的郎杰学地体三叠系短缩率达75%.大于前人研究的特提斯喜马拉雅56%~6O%的短缩率.通过对比,对3个地体短缩变形的规律进行了分析,认为各地体内部短缩作用并不是一个连续均匀的过程,陆内变形主要是通过稳定地体边界和大型逆冲构造带来吸收的;拉萨地体和羌塘地体新生代内部变形较小.  相似文献   

13.
East and Southeast Asia is a complex assembly of allochthonous continental terranes, island arcs, accretionary complexes and small ocean basins. The boundaries between continental terranes are marked by major fault zones or by sutures recognized by the presence of ophiolites, mélanges and accretionary complexes. Stratigraphical, sedimentological, paleobiogeographical and paleomagnetic data suggest that all of the East and Southeast Asian continental terranes were derived directly or indirectly from the Iran-Himalaya-Australia margin of Gondwanaland. The evolution of the terranes is one of rifting from Gondwanaland, northwards drift and amalgamation/accretion to form present day East Asia. Three continental silvers were rifted from the northeast margin of Gondwanaland in the Silurian-Early Devonian (North China, South China, Indochina/East Malaya, Qamdo-Simao and Tarim terranes), Early-Middle Permian (Sibumasu, Lhasa and Qiangtang terranes) and Late Jurassic (West Burma terrane, Woyla terranes). The northwards drift of these terranes was effected by the opening and closing of three successive Tethys oceans, the Paleo-Tethys, Meso-Tethys and Ceno-Tethys. Terrane assembly took place between the Late Paleozoic and Cenozoic, but the precise timings of amalgamation and accretion are still contentious. Amalgamation of South China and Indochina/East Malaya occurred during the Early Carboniferous along the Song Ma Suture to form “Cathaysialand”. Cathaysialand, together with North China, formed a large continental region within the Paleotethys during the Late Carboniferous and Permian. Paleomagnetic data indicate that this continental region was in equatorial to low northern paleolatitudes which is consistent with the tropical Cathaysian flora developed on these terranes. The Tarim terrane (together with the Kunlun, Qaidam and Ala Shan terranes) accreted to Kazakhstan/Siberia in the Permian. This was followed by the suturing of Sibumasu and Qiangtang to Cathaysialand in the Late Permian-Early Triassic, largely closing the Paleo-Tethys. North and South China were amalgamated in the Late Triassic-Early Jurassic and finally welded to Laurasia around the same time. The Lhasa terrane accreted to the Sibumasu-Qiangtang terrane in the Late Jurassic and the Kurosegawa terrane of Japan, interpreted to be derived from Australian Gondwanaland, accreted to Japanese Eurasia, also in the Late Jurassic. The West Burma and Woyla terranes drifted northwards during the Late Jurassic and Early Cretaceous as the Ceno-Tethys opened and the Meso-Tethys was destroyed by subduction beneath Eurasia and were accreted to proto-Southeast Asia in the Early to Late Cretaceous. The Southwest Borneo and Semitau terranes amalgamated to each other and accreted to Indochina/East Malaya in the Late Cretaceous and the Hainanese terranes probably accreted to South China sometime in the Cretaceous.  相似文献   

14.
青藏高原主要地体地壳短缩作用研究现状及存在的问题   总被引:1,自引:0,他引:1  
施美凤  李亚林  黄继钧 《地质通报》2010,29(203):286-296
在对喜马拉雅、拉萨和羌塘3个地体已有的有关地壳短缩研究成果系统分析的基础上,对3个地体进行了平衡剖面恢复:北羌塘侏罗系短缩率为25.18%,南羌塘短缩率为33.57%;对拉萨地体南段(措勤盆地南部坳褶带)上白垩统恢复得出其短缩率为20.68%,北段中部坳褶带到班公湖-怒江缝合带南缘短缩率为25.3%;地处特提斯喜马拉雅地体东段的郎杰学地体三叠系短缩率达75%,大于前人研究的特提斯喜马拉雅56%~60%的短缩率。通过对比,对3个地体短缩变形的规律进行了分析,认为各地体内部短缩作用并不是一个连续均匀的过程,陆内变形主要是通过稳定地体边界和大型逆冲构造带来吸收的;拉萨地体和羌塘地体新生代内部变形较小。  相似文献   

15.
东北地区由多个地体组成,其运动特征与邻区西伯利亚和华北等板块具有明显差异,有其独特的演化历史。古地磁资料支持将其划为独立构造单元,称之为东北地体群。古地磁资料表明,东北主要地体古生代处在南纬低纬度地区,中生代诸地体共同快速北移,其纬向运移的平均速度约为3.8cm/a。于白垩纪中期就位于现今位置。  相似文献   

16.
通过对豫西龙潭沟断层两侧的基底岩性、出露地层、构造景观、岩浆岩的分布、地热异常、煤变质程度等地质异常现象及成因分析,提出龙潭沟断层是嵩箕地体与崤熊地体的拼接线的新观点,并对两地体的拼接时代与识别标志进行了研究,进而对嵩箕、崤熊两地体的构造重新解释,并依此对两地体内的地质找矿拓宽了思路。  相似文献   

17.
East and Southeast Asia comprises a complex assembly of allochthonous continental lithospheric crustal fragments (terranes) together with volcanic arcs, and other terranes of oceanic and accretionary complex origins located at the zone of convergence between the Eurasian, Indo-Australian and Pacific Plates. The former wide separation of Asian terranes is indicated by contrasting faunas and floras developed on adjacent terranes due to their prior geographic separation, different palaeoclimates, and biogeographic isolation. The boundaries between Asian terranes are marked by major geological discontinuities (suture zones) that represent former ocean basins that once separated them. In some cases, the ocean basins have been completely destroyed, and terrane boundaries are marked by major fault zones. In other cases, remnants of the ocean basins and of subduction/accretion complexes remain and provide valuable information on the tectonic history of the terranes, the oceans that once separated them, and timings of amalgamation and accretion. The various allochthonous crustal fragments of East Asia have been brought into close juxtaposition by geological convergent plate tectonic processes. The Gondwana-derived East Asia crustal fragments successively rifted and separated from the margin of eastern Gondwana as three elongate continental slivers in the Devonian, Early Permian and Late Triassic–Late Jurassic. As these three continental slivers separated from Gondwana, three successive ocean basins, the Palaeo-Tethys,. Meso-Tethys and Ceno-Tethys, opened between these and Gondwana. Asian terranes progressively sutured to one another during the Palaeozoic to Cenozoic. South China and Indochina probably amalgamated in the Early Carboniferous but alternative scenarios with collision in the Permo–Triassic have been suggested. The Tarim terrane accreted to Eurasia in the Early Permian. The Sibumasu and Qiangtang terranes collided and sutured with Simao/Indochina/East Malaya in the Early–Middle Triassic and the West Sumatra terrane was transported westwards to a position outboard of Sibumasu during this collisional process. The Permo–Triassic also saw the progressive collision between South and North China (with possible extension of this collision being recognised in the Korean Peninsula) culminating in the Late Triassic. North China did not finally weld to Asia until the Late Jurassic. The Lhasa and West Burma terranes accreted to Eurasia in the Late Jurassic–Early Cretaceous and proto East and Southeast Asia had formed. Palaeogeographic reconstructions illustrating the evolution and assembly of Asian crustal fragments during the Phanerozoic are presented.  相似文献   

18.
This paper summaries tectonic settings and mineral parageneses of several recognized ultrahigh-pressure (UHP) terranes other than the well-studied Kokchetav Massif of northern Kazakhstan, the Western Gneiss Region of Norway, the Dora-Maira massif of the Western Alps, and the Dabie-Sulu terrane of east-central China. Diamond-bearing terranes include the Beni Bousera/Ronda peridotite massif, the Erzgebirge Crystalline Complex, mantle peridotite from a Tibetan ophiolite, and possibly the Maksyutov Complex. Coesite-bearing UHP terranes are the Zermatt-Saas area, Western Alps; the Mali eclogites from West Africa; the Makabal complex of western Tien Shan; the Bohemian massif; and the newly reported Central Indonesia terrane and Himalayan eclogites from the upper Kaghan Valley of Pakistan. Except for the diamond-bearing Tibetan ophiolite, most UHP terranes share similar petrotectonic assemblages and lie within major continental collision belts in Eurasia and Africa. Using new approaches (including new geobarometers) and technologies, additional UHP terranes are expected to be recognized in other Phanenorozic orogenic sutures.  相似文献   

19.
The ages and paleogeographic affinities of basement rocks of Tibetan terranes are poorly known. New U-Pb zircon geochronologic data from orthogneisses of the Amdo basement better resolve Neoproterozoic and Cambro-Ordovician magmatism in central Tibet. The Amdo basement is exposed within the Bangong suture zone between the Lhasa and Qiangtang terranes and is composed of granitic orthogneisses with subordinate paragneisses and metasedimentary rocks. The intermediate-felsic orthogneisses show a bimodal distribution of Neoproterozoic (920-820 Ma) and Cambro-Ordovician (540-460 Ma) crystallization ages. These and other sparse basement ages from Tibetan terranes suggest the plateau is underlain by juvenile crust that is Neoproterozoic or younger; its young age and weaker rheology relative to cratonic blocks bounding the plateau margins likely facilitated the propagation of Indo-Asian deformation far into Asia. The Neoproterozoic ages post-date Rodinia assembly and magmatism of similar ages is documented in the Qaidaim-Kunlun terrane, South China block, the Aravalli-Delhi craton in NW India, the Eastern Ghats of India, and the Prince Charles mountains in Antarctica. The Amdo Neoproterozoic plutons cannot be unambiguously related to one of these regions, but we propose that the Yangtze block of the South China block is the most likely association, with the Amdo basement representing a terrane that possibly rifted from the active Yangtze margin in the middle Neoproterozoic. Cambro-Ordovician granitoids are ubiquitous throughout Gondwana as a product of active margin tectonics following Gondwana assembly and indicate that the Lhasa-Qiangtang terranes were involved in these tectono-magmatic events. U-Pb detrital zircon analysis of two quartzites from the Amdo basement suggest that the protoliths were Carboniferous-Permian continental margin strata widely deposited across the Lhasa and Qiangtang terranes. The detrital zircon age spectra of the upper Paleozoic Tibetan sandstones and other rocks deposited in East Gondwana during the late Neoproterozoic and Paleozoic are all quite similar, making it difficult to use the age spectra for paleogeographic determinations. There is a suggestion in the data that the Qiangtang terrane may have been located further west along Gondwana’s northern boundary than the Lhasa terrane, but more refined spatial and temporal data are needed to verify this configuration.  相似文献   

20.
中国喜马拉雅构造运动的陆内变形特征与油气矿藏富集   总被引:12,自引:0,他引:12  
贾承造 《地学前缘》2007,14(4):96-104
在前人研究的基础上,结合近年来在油气勘探中不断积累的地质资料和地质认识,提出了中国喜马拉雅构造运动的陆内变形特征及其分布规律受控于小型克拉通板块拼贴的基底结构和印/欧碰撞与太平洋板块俯冲所主导的双重控制因素;喜马拉雅构造运动的发育特征主要表现为三种动力学机制:青藏高原隆升、盆地与造山带体制和东部拉张活动。喜马拉雅构造运动的大地构造格局及其构造变形分布规律集中体现为4个构造域:青藏高原隆升区、环青藏高原盆山体系、稳定区和环西太平洋裂谷活动区。我国沉积盆地在喜马拉雅构造运动中的构造特征分为三种类型:(1)东部渤海湾、松辽等盆地受拉张构造环境控制的裂谷沉降;(2)中部四川、鄂尔多斯等盆地受青藏高原的向东推挤、盆缘冲断、盆内抬升剥蚀;(3)西部的塔里木、准噶尔、柴达木等盆地受青藏高原的向北推挤、冲断挠曲沉降,表现为克拉通单边或双边的压缩挠曲沉降与克拉通内部的冲断隆升沉降等多种盆山耦合形式。喜马拉雅构造运动控制着中国油气晚期定位与富集成藏,主要体现在:盆地的沉积与成藏,形成新生界自生自储的含油气盆地和油气藏;圈闭形成与油气运聚成藏;早期油气藏的调整和再分配;油气藏的破坏。  相似文献   

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