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1.
The Arctida Craton and Neoproterozoic-Mesozoic orogenic belts of the Circum-Polar region 总被引：1，自引：0，他引：1
An attempt is made to characterize an assembly of Arctic tectonic units formed before the opening of the Arctic Ocean. This
assembly comprises the epi-Grenville Arctida Craton (a fragment of Rodinia) and the marginal parts of the Precambrian Laurentia,
Baltica, and Siberian cratons. The cratons are amalgamated by orogenic belts (trails of formerly closed oceans). These are
the Late Neoproterozoic belts (Baikalides), Middle Paleozoic belts (Caledonides), Permo-Triassic belts (Hercynides), and Early
Cretaceous belts (Late Kimmerides). Arctida encompasses an area from the Svalbard Archipelago in the west to North Alaska
in the east. The Svalbard, Barents, Kara, and other cratons are often considered independent Precambrian minicratons, but
actually they are constituents of Arctida subsequently broken down into several blocks. The Neoproterozoic orogenic belt extends
as a discontinuous tract from the Barents-Ural-Novaya Zemlya region via the Taimyr Peninsula and shelf of the East Siberian
Sea to North Alaska as an arcuate framework of Arctida, which separates it from the Baltica and Siberian cratons. The Caledonian
orogenic belt consisting of the Scandian and Ellesmerian segments frames Arctida on the opposite side, separating it from
the Laurentian Craton. The opposite position of the Baikalian and Caledonian orogenic belts in the Arctida framework makes
it possible to judge about the time when the boundaries of this craton formed as a result of its detachment from Rodinia.
The Hercynian orogenic belt in the Arctic Region comprises the Novozemel’sky (Novaya Zemlya) and Taimyr segments, which initially
were an ending of the Ural Hercynides subsequenly separated by a strike-slip fault. The Mid-Cretaceous (Late Kimmerian) orogenic
belt as an offset of Pacific is divergent. It was formed under the effect of the opened Canada Basin and accretion and collision
at the Pacific margins. The undertaken typification of pre-Late Mesozoic tectonic units, for the time being debatable in some
aspects, allows reconstruction of the oceanic basins that predated the formation of the Arctic Ocean. 相似文献
2.
3.
N. P. Laverov L. I. Lobkovsky M. V. Kononov N. L. Dobretsov V. A. Vernikovsky S. D. Sokolov E. V. Shipilov 《Geotectonics》2013,47(1):1-30
The tectonic evolution of the Arctic Region in the Mesozoic and Cenozoic is considered with allowance for the Paleozoic stage of evolution of the ancient Arctida continent. A new geodynamic model of the evolution of the Arctic is based on the idea of the development of upper mantle convection beneath the continent caused by subduction of the Pacific lithosphere under the Eurasian and North American lithospheric plates. The structure of the Amerasia and Eurasia basins of the Arctic is shown to have formed progressively due to destruction of the ancient Arctida continent, a retained fragment of which comprises the structural units of the central segment of the Arctic Ocean, including the Lomonosov Ridge, the Alpha-Mendeleev Rise, and the Podvodnikov and Makarov basins. The proposed model is considered to be a scientific substantiation of the updated Russian territorial claim to the UN Commission on the determination of the Limits of the Continental Shelf in the Arctic Region. 相似文献
4.
The Vendian (Baikalian), Late Devonian (Ellesmerian), and Mid-Cretaceous (Brookian) orogenies were three cardinal events in the history of formation and transformation of the continental crust in the eastern Arctic region. The epi-Baikalian Hyperborean Craton was formed by the end of the Vendian (660–550 Ma), when the Archean-Proterozoic Hyperborean continental block was built up by the Baikalian orogenic belt and concomitant collision granitoids. As judged from the localization of deepwater facies, the Early Paleozoic ocean occupied the western part of the Canadian Arctic Archipelago, western Alaska, and the southern framework of the Canada and Podvodnikov basins and was connected with the Iapetus ocean. The closure of the Early Paleozoic Arctic basins is recorded in two surfaces of structural unconformities corresponding to the pre-Middle Devonian Scandian orogenic phase and the Late Devonian Ellesmerian Orogeny; each tectonic phase was accompanied by dislocations and metamorphism. The Ellesmerian collision was crucial in the Caledonian tectogenesis. The widespread Late Devonian-Mississippian rifting probably was a reflection of postorogenic relaxation. As a result, the vast epi-Caledonian continental plate named Euramerica, or Laurussia, was formed at the Devonian-Carboniferous boundary. The East Arctic segment of this plate is considered in this paper. In the Devonian, the Angayucham ocean, which was connected with the Paleoasian and Uralian oceans [62], separated this plate from the Siberian continent. The South Anyui Basin most likely was a part of this Paleozoic oceanic space. The shelf sedimentation on the epi-Caledonian plate in the Carboniferous and Permian was followed by subsidence and initial rifting in the Triassic and Jurassic, which further gave way to the late Neocomian-early Albian spreading in the Canada Basin that detached the Chukchi Peninsula-Alaska microplate from the continental plate [25]. The collision of this microplate with the Siberian continent led to the closure of the South Anyui-Angayucham ocean and the development of the Mid-Cretaceous New Siberian-Chukchi-Brooks Orogenic System that comprised the back Chukchi Zone as a hinterland and the frontal New Siberian-Wrangel-Herald-Lisburne-Brooks Thrust Zone as a foreland; the basins coeval with thrusting adjoined the foreland. Collision started in the Late Jurassic; however, the peak of the orogenic stage fell on the interval 125–112 Ma, when ophiolites had been obducted on the margin of the Chukchi Peninsula-Alaska microplate along with folding and thrusting accompanied by an increase in the crust’s thickness, amphibolite-facies metamorphism, and growth of granite-gneiss domes. The magmatic diapir of the De Long Arch that grew within the continental plate in the Mid-Cretaceous reflected a global pulse of the lower mantle upwelling that coincided with the maximum opening of the Canada Basin. The present-day appearance of the eastern Arctic region arose in the Late Mesozoic and Cenozoic owing to the opening of the Amerasia and Eurasia oceans. Sedimentary basins of various ages and origins—including the Late Devonian-Early Carboniferous grabens, the spatially coinciding Late Jurassic-Early Cretaceous rifts related to the opening of the Canada Basin, the syncollision basins in front of the growing orogen, and the Cretaceous-Cenozoic basins coeval with strike-slip faulting and rifting at the final stages of orogenic compression and during the opening of the Eurasia ocean were telescoped on sea shelves. 相似文献
5.
Tectonics and petroleum potential of the underexplored East Arctic area have been investigated as part of an IPY (International Polar Year) project. The present-day scenery of the area began forming with opening of the Amerasia Ocean (Canada and Podvodnikov—Makarov Basins) in the Late Jurassic—Early Cretaceous and with Cretaceous—Cenozoic rifting related to spreading in the Eurasia Basin. The opening of oceans produced pull-apart and rift basins along continental slopes and shelves of the present-day Arctic fringing seas, which lie on a basement consisting of fragments of the Hyperborean craton and Early Paleozoic to Middle Cretaceous orogens. By analogy with basins of the Arctic and Atlantic passive margins, the Cretaceous—Cenozoic shelf and continental slope basins may be expected to have high petroleum potential, with oil and gas accumulations in their sediments and basement. 相似文献
6.
L. A. Daragan-Sushchova O. V. Petrov N. N. Sobolev Yu. I. Daragan-Sushchov L. R. Grin’ko N. A. Petrovskaya 《Geotectonics》2015,49(6):469-484
The structure of the sedimentary cover and acoustic basement in the northeastern Russian Arctic region is analyzed. Beneath the western continuation of the North Chukchi trough and Vil’kitskii trough, a Late Caledonian (Ellesmere) folded and metamorphozed basement is discovered. It is supposed that Caledonides continue further into the Podvodnikov Basin until the Geofizikov branch. A large magnetic anomaly in the Central Arctic zone has been verified by seismostratigraphic data: the acoustic basement beneath the Mendeleev (and partially Alpha) Ridge is overlain by trapps. Wave field analysis showed that the acoustic basement of the Lomonosov Ridge has folded structure, whereas beneath the Mendeleev Ridge, the sporadic presence of a weakly folded stratum of Paleozoic platform deposits is interpreted. It is supposed that the Caledonian and Late Cimmerian fold belts in the periphery of the Arctida paleocontinent appeared as a result of collision between arctic continental masses and southern ones. After Miocene extension and block displacements identified from appearance of horsts, grabens, and transverse rises both on the shelf and in the ocean, a general subsidence took place and the present-day shelf, slope, and the deepwater part of the Arctic Ocean formed. 相似文献
7.
E. V. Shipilov 《Geotectonics》2008,42(2):105-124
Chronological succession in the formation of spreading basins is considered in the context of reconstruction of breakdown of Wegener’s Pangea and the development of the geodynamic system of the Arctic Ocean. This study made it possible to indentify three temporally and spatially isolated generations of spreading basins: Late Jurassic-Early Cretaceous, Late Cretaceous-Early Cenozoic, and Cenozoic. The first generation is determined by the formation, evolution, and extinction of the spreading center in the Canada Basin as a tectonic element of the Amerasia Basin. The second generation is connected to the development of the Labrador-Baffin-Makarov spreading branch that ceased to function in the Eocene. The third generation pertains to the formation of the spreading system of interrelated ultraslow Mohna, Knipovich, and Gakkel mid-ocean ridges that has functioned until now in the Norwegian-Greenland and Eurasia basins. The interpretation of the available geological and geophysical data shows that after the formation of the Canada Basin, the Arctic region escaped the geodynamic influence of the Paleopacific, characterized by spreading, subduction, formation of backarc basins, collision-related processes, etc. The origination of the Makarov Basin marks the onset of the oceanic regime characteristic of the North Atlantic (intercontinental rifting, slow and ultraslow spreading, separation of continental blocks (microcontinents), extinction of spreading centers of primary basins, spreading jumps, formation of young spreading ridges and centers, etc., are typical) along with retention of northward propagation of spreading systems both from the Pacific and Atlantic sides. The aforesaid indicates that the Arctic Ocean is in fact a hybrid basin or, in other words, a composite heterogeneous ocean in respect to its architectonics. The Arctic Ocean was formed as a result of spatial juxtaposition of two geodynamic systems different in age and geodynamic style: the Paleopacific system of the Canada Basin that finished its evolution in the Late Cretaceous and the North Atlantic system of the Makarov and Eurasia basins that came to take the place of the Paleopacific system. In contrast to traditional views, it has been suggested that asymmetry of the northern Norwegian-Greenland Basin is explained by two-stage development of this Atlantic segment with formation of primary and secondary spreading centers. The secondary spreading center of the Knipovich Ridge started to evolve approximately at the Oligocene-Miocene transition. This process resulted in the breaking off of the Hovgard continental block from the Barents Sea margin. Thus, the breakdown of Wegener’s Pangea and its Laurasian fragments with the formation of young spreading basins was a staged process that developed nearly from opposite sides. Before the Late Cretaceous (the first stage), the Pangea broke down from the side of Paleopacific to form the Canada Basin, an element of the Amerasia Basin (first phase of ocean formation). Since the Late Cretaceous, destructive pulses came from the side of the North Atlantic and resulted in the separation of Greenland from North America and the development of the Labrador-Baffin-Makarov spreading system (second phase of ocean formation). The Cenozoic was marked by the development of the second spreading branch and the formation of the Norwegian-Greenland and Eurasia oceanic basins (third phase of ocean formation). Spreading centers of this branch are functioning currently but at an extremely low rate. 相似文献
8.
9.
V.A. Vernikovsky N.L. Dobretsov D.V. Metelkin N.Yu. Matushkin I.Yu. Koulakov 《Russian Geology and Geophysics》2013,54(8):838-858
The particularities of the current tectonic structure of the Russian part of the Arctic region are discussed with the division into the Barents–Kara and Laptev–Chukchi continental margins. We demonstrate new geological data for the key structures of the Arctic, which are analyzed with consideration of new geophysical data (gravitational and magnetic), including first seismic tomography models for the Arctic. Special attention is given to the New Siberian Islands block, which includes the De Long Islands, where field work took place in 2011. Based on the analysis of the tectonic structure of key units, of new geological and geophysical information and our paleomagnetic data for these units, we considered a series of paleogeodynamic reconstructions for the arctic structures from Late Precambrian to Late Paleozoic. This paper develops the ideas of L.P. Zonenshain and L.M. Natapov on the Precambrian Arctida paleocontinent. We consider its evolution during the Late Precambrian and the entire Paleozoic and conclude that the blocks that parted in the Late Precambrian (Svalbard, Kara, New Siberian, etc.) formed a Late Paleozoic subcontinent, Arctida II, which again “sutured” the continental masses of Laurentia, Siberia, and Baltica, this time, within Pangea. 相似文献
10.
We discuss the potential geodynamic connections between Paleozoic arc development along the flanks of the interior (e.g. the Iapetus and Rheic) oceans and the exterior Paleopacific Ocean. Paleozoic arcs in the Iapetus and Rheic oceanic realms are preserved in the Appalachian–Caledonide and Variscan orogens, and in the Paleopacific Ocean realm they are preserved in the Terra Australis Orogen. Potential geodynamic connections are suggested by paleocontinental reconstructions showing Cambrian–Early Ordovician contraction of the exterior ocean as the interior oceans expanded, and subsequent Paleozoic expansion of the exterior oceans while the interior oceans contracted. Subduction initiated in the eastern segment of Iapetus at ca. 515 Ma and Early to Middle Ordovician orogenesis along the flanks of this ocean is highlighted by arc–continent collisions and ophiolite obductions. Over a similar time interval, subduction and orogenesis took place in the exterior ocean and included formation of the Macquarie arc in the Tasmanides of Eastern Australia and the Famatina arc and correlatives in the periphery of the proto-Andean margin of Gondwana. Major changes in the style of subduction (from retreating to advancing) in interior oceans occurred during the Silurian, following accretion of the peri-Gondwanan terranes and Baltica, and closure of the northeastern segment of Iapetus. During the same time interval, subduction in the Paleopacific Ocean was predominantly in a retreating mode, although intermittent episodes of contraction closed major marginal basins. In addition, however, there were major disturbances in the Earth tectonic systems during the Ordovician, including an unprecedented rise in marine life diversity, as well as significant fluctuations in sea level, atmospheric CO2, and 87Sr/86Sr and 13C in marine strata carbonates. Stable and radiogenic isotopic data provide evidence for the addition of abundant mantle-derived magma, fluids and large mineral deposits that have a significant mantle-derived component. When considered together, the coeval, profound changes in the style of tectonic activity and the disturbances recorded in Earth Systems are consistent with the emergence of a superplume during the Ordovician. We speculate that the emergence of a superplume triggered by slab avalanche events within the Iapetus and Paleopacific oceans was associated with the establishment of a new geoid high within the Paleopacific regime, the closure of the interior Rheic Ocean and the amalgamation of Laurussia and Gondwana, which was a key event in the Late Carboniferous amalgamation of Pangea. 相似文献
11.
古亚洲洋与古特提斯洋关系初探 总被引：1，自引：0，他引：1
从板块构造研究中国古生代洋陆关系和构造-岩浆-成矿作用,离不开对古亚洲洋和古特提斯洋的关系判断,特别是对于中国西北部的研究,两个古生代大洋形成演化和关系是理清重要地质构造和成矿事件的关键。本文认为早古生代的原特提斯洋与古亚洲洋应连为一体,合称古亚洲-原特提斯洋,简称古亚洲洋。古亚洲洋是发育于早古生代劳亚大陆与冈瓦纳大陆之间的大洋,金川超大型铜镍矿床的形成是元古宙罗迪尼亚超大陆裂解三叉裂谷开启大洋的开始,塔里木陆块作为古亚洲洋南岸的一个陆块,早古生代的昆仑洋、祁连洋和秦岭洋只是古亚洲洋的分支或次生洋盆,这些次生洋盆于志留纪末闭合,古亚洲洋主洋则直到晚古生代泥盆纪末才闭合。石炭纪天山及邻区是古亚洲洋闭合后板块构造后碰撞机制与地幔柱作用提供热动力的两种地球动力学机制并存的构造背景,为大规模壳幔混合(染)岩浆作用和成矿爆发提供了可能。古特提斯洋是古亚洲洋在晚古生代的发展和继承,东昆仑夏日哈木超大型铜镍矿床的产生是冈瓦纳大陆北侧志留纪末破裂三叉裂谷开启大洋的开始,塔里木和华北等泛华夏陆块群构成了古特提斯洋北岸陆缘,石炭纪大洋形成,西昆仑玛尔坎苏大型优质锰矿可能就形成于大洋北侧被动大陆边缘的浅海或陆表海,成矿物质则很可能来自于同时代的大洋中脊。德尔尼大型铜钴矿为晚石炭世大洋中脊塞浦路斯型块状硫化物矿床。而铜峪沟大型铜矿和大场大型金矿等则分别为古特提斯洋消减俯冲岛弧岩浆作用矽卡岩-斑岩矿床和浅成低温热液矿床。中三叠世末古特提斯洋闭合。 相似文献
12.
《China Geology》2022,5(4):555-578
The eastern Central Asian Orogenic Belt (CAOB) in NE China is a key area for investigating continental growth. However, the complexity of its Paleozoic geological history has meant that the tectonic development of this belt is not fully understood. NE China is composed of the Erguna and Jiamusi blocks in the northern and eastern parts and the Xing’an and Songliao-Xilinhot accretionary terranes in the central and southern parts. The Erguna and Jiamusi blocks have Precambrian basements with Siberia and Gondwana affinities, respectively. In contrast, the Xing ’an and Songliao-Xilinhot accretionary terranes were formed via subduction and collision processes. These blocks and terranes were separated by the Xinlin-Xiguitu, Heilongjiang, Nenjiang, and Solonker oceans from north to south, and these oceans closed during the Cambrian (ca. 500 Ma), Late Silurian (ca. 420 Ma), early Late Carboniferous (ca. 320 Ma), and Late Permian to Middle Triassic (260 –240 Ma), respectively, forming the Xinlin-Xiguitu, Mudanjiang-Yilan, Hegenshan-Heihe, Solonker-Linxi, and Changchun-Yanji suture zones. Two oceanic tectonic cycles took place in the eastern Paleo-Asian Ocean (PAO), namely, the Early Paleozoic cycle involving the Xinlin-Xiguitu and Heilongjiang oceans and the late Paleozoic cycle involving the Nenjiang-Solonker oceans. The Paleozoic tectonic pattern of the eastern CAOB generally shows structural features that trend east-west. The timing of accretion and collision events of the eastern CAOB during the Paleozoic youngs progressively from north to south. The branch ocean basins of the eastern PAO closed from west to east in a scissor-like manner. A bi-directional subduction regime dominated during the narrowing and closure process of the eastern PAO, which led to “soft collision” of tectonic units on each side, forming huge accretionary orogenic belts in central Asia.©2022 China Geology Editorial Office. 相似文献
13.
The integration of information obtained from onshore and offshore geological and geophysical research undertaken in the context
of the International Polar Year has led to the following results. The continental crust is widespread in the Arctic not only
beneath the shelves of polar seas in the framework of the Amerasia Basin but also in the Chukchi-Northwind, Lomonosov, and
Mendeleev ridges; a combination of continental and oceanic crusts is inferred in the Alpha Ridge. The Amerasia Basin is not
an indivisible element of the Arctic Ocean either in genetic or structural terms but consists of variously oriented basins
different in age. The first, Mesozoic “minor ocean” of the Arctic Ocean—the Canada Basin—arose as a result of impact of the
Arctic plume on the high-latitude region of Pangea. This inference is supported by the vast Central Arctic igneous province
that comprises the Jurassic-Mid-Cretaceous within-plate and ocean-island basaltic and associated rocks. The rotational mechanism
of opening of this basin is explained by the slant path of the plume head motion, which resulted in breaking-off and displacement
of a fragment of Pangea. The effect of the Arctic plume was expressed during all stages of the opening of the Canada Basin
and exerted effects on the adjacent part of the Eurasian continent during the formation of the Verkhoyansk-Chukotka tectonic
domain. The Canada Basin was an element of the segmented system of Atlantic spreading ridges, while the Arctic plume that
initiated its evolution was genetically related to the episodically acting African-Atlantic superplume. In comparison with
the Pacific superplume, the low productivity of African-Atlantic lower mantle upwelling became the cause of slow and ultraslow
spreading in the Atlantic and Arctic oceans and determined the passive character of their margins, including the Canada Basin. 相似文献
14.
苏浙皖地区：中—古生界海相烃源岩及含油气性 总被引：4，自引：0，他引：4
从晚震旦世开始至中三叠世,苏泊皖地区沉积了三套巨厚的烃源岩系：上震旦统－上奥陶统,石炭系－二叠系、下三叠统。三套烃源岩热演化特点不同,特别是下古生界油源岩经历了加里东、印支－燕山期构造阶段的热演化,已达过成熟干气阶段;上古生界基本处于生油阶段晚期;三叠系大部处于成熟生油阶段,少数处于未成熟阶段。区内下古生界烃源岩经历了两次成油过程,第一次在加里东运动前的盆地沉降阶段,第二次在中里东运动后晚古生代陆 相似文献
15.
北极地区地质构造及主要构造事件 总被引：1，自引：0，他引：1
北极地区范围很广,北极圈面积达2 100×104 km2,区域地质复杂。通过对北极地区区域地质编图,笔者认为前寒武纪主要由波罗的、劳伦和西伯利亚三大克拉通,以及其间的微板块或地块组成。主要造山带包括新元古代-早寒武世的贝加尔造山带、晚志留世-早石炭世的加里东造山带、晚古生代-早中生代的海西造山带、晚中生代的上扬斯克造山带、新西伯利亚造山带与楚科奇-布鲁克斯造山带。根据北极地区区域地质构造特征,显生宙以来经历的构造事件大致包括:新元古代-早寒武世的贝加尔运动,致使波罗的古陆与斯瓦尔巴-喀拉地块碰撞造山;晚泥盆世-早石炭世的加里东运动,在劳伦古陆周边形成规模巨大的加里东造山带;晚古生代的海西运动,波罗的古陆与西伯利亚古陆的碰撞造山形成海西造山带;北极阿拉斯加-楚科奇微板块裂离加拿大边缘,侏罗纪加拿大海盆开始张开;早白垩世,阿拉斯加-楚科奇微板块继续与西伯利亚碰撞,阿纽伊洋(Anyui Ocean)消亡,形成上扬斯克-布鲁克斯造山带。受北极调查程度影响,许多问题有待进一步研究。 相似文献
16.
R. Damian Nance Gabriel Guti errez-Alonso J. Duncan Keppie Ulf Linnemann J. Brendan Murphy Cecilio Quesa Rob A. Strachan Nigel H. Woodcock 《地学前缘(英文版)》2012,3(2):125-135
The Rheic Ocean was one of the most important oceans of the Paleozoic Era.It lay between Laurentia and Gondwana from the Early Ordovician and closed to produce the vast Ouachita-Alleghanian -Variscan orogen during the assembly of Pangea.Rifting began in the Cambrian as a continuation of Neoproterozoic orogenic activity and the ocean opened in the Early Ordovician with the separation of several Neoproterozoic arc terranes from the continental margin of northern Gondwana along the line of a former suture.The rapid rate of ocean opening suggests it was driven by slab pull in the outboard lapetus Ocean.The ocean reached its greatest width with the closure of lapetus and the accretion of the periGondwanan arc terranes to Laurentia in the Silurian.Ocean closure began in the Devonian and continued through the Mississippian as Gondwana sutured to Laurussia to form Pangea.The ocean consequently plays a dominant role in the Appalachian-Ouachita orogeny of North America,in the basement geology of southern Europe,and in the Paleozoic sedimentary,structural and tectonothermal record from Middle America to the Middle East.Its closure brought the Paleozoic Era to an end. 相似文献
17.
中央造山带的演化及其特点 总被引：105，自引：12，他引：93
中央造山带原型是由一列微板块加上分别位于其北面和同面的两列不同时期的小洋盆组成,微板块群的主体是柴达木,秦岭,大别－苏鲁,还加上祁连,元古代末至早古生代早期,北列拉张成多岛小洋盆,它们在加里东档期关闭,并在微板块群北缘形成前陆盆地带,南列形成裂陷槽,在加里东期末关闭,一般不造山,晚古生代,微板块群与欧亚板块合为一体,并总体北移,南列出现泥盆（个别）石炭二叠纪的小洋盆,属于古特提斯洋的一部分,洋盆在 相似文献
18.
贺西地区晚古生代早中期同沉积断层的发现及其意义 总被引：1，自引：0，他引：1
贺西地区处于北祁连加里东褶皱带、阿拉善地块与鄂尔多斯地块的交汇处,该区晚古生代早中期处于早古生代洋盆体制与中生代陆内盆地发育期的转换时期,其盆地性质及成因争议颇多。在贺兰山地区工作中,作者发现晚泥盆世、早石炭世同沉积断层,并详细追踪了上泥盆统、下石炭统与上下地层的接触关系;结合野外相关地质现象及前人的区域地质研究成果,对贺西地区晚古生代早期盆地的性质及其成因进行了讨论,认为该期盆地既非碰撞裂谷,也非前陆盆地,而是造山后伸展型上叠盆地,同时认为该伸展盆地的形成与古特提斯洋打开呈现同步性,具有一定的区域地质意义。 相似文献
19.
新疆西准噶尔克拉玛依-额敏一带广泛出露古生代的物质建造,记录着古亚洲洋演化的重要信息.古生代期间特别是晚古生代期间经历了复杂的洋陆转换过程,残留了系列近东西向及北东向蛇绿构造混杂岩系以及古大陆边缘的增生体系,造就了研究区复杂的岩石地层系统.目前对西准噶尔志留系、泥盆系构造古地理属性及志留纪-泥盆纪构造格局的刻画并不够精细.通过详细地野外地质调查及室内数据综合分析,结合前人的研究资料,对西准噶尔克拉玛依-额敏一带志留系及泥盆系代表性的岩石地层的构造古地理属性进行了界定,并在此基础上,对研究区志留纪-泥盆纪的弧盆格局进行探讨.综合分析认为志留纪西准噶尔克拉玛依-额敏一带古亚洲洋开始强烈的俯冲消减,泥盆纪古亚洲洋进入全面俯冲拼贴的演化阶段,形成多块体拼贴增生的多岛弧盆格局.泥盆纪后古亚洲洋在研究区开始进入残余洋盆的演化阶段. 相似文献
20.
Paleozoic accretionary terranes in Northern Tianslian, NW China 总被引：14，自引：2，他引：12
Liangshu Shu Yuntang Chen Huafu Lu Jacques Charvet Sebastie Laurent-Charvet Donghao Yin 《中国地球化学学报》2000,19(3):193-202
During the paleozoic,the Northern Tianshan region of China in Central Asia consists of 7 allochthonous terranes which were situated in the ancient sino-Mongolian Ocean as volcanic arcs and splitted continental fragments.The tectonic framework was similar to that of Southwest pacific today,In the Late Paleozoic,these terranes started mutual amalgamation to cause strong thrusting.At thd end of Carboniferous,the Sino-mongolian ocean including several inter-terrane small sea basins closed and these terranes accreted on the margins of the Siberian and Tarim continents,The 6 ophiolitic zones zomong the terranes recorded this collision event. 相似文献