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1.
《China Geology》2018,1(2):236-256
The continent of China is grouped into Pan–Cathaysian blocks, Laurasia and Gondwana Continental margins and relics of three oceans-Paleoasian, Tethys, and Pacific as a whole. In detail, the continent of China grew up by coalescence of three blocks or platforms (North China, Tarim and Yangtze) and eight orogenic belts (Altay–Inner Mongolia–Daxinganling, Tianshan–Junggar–Beishan, Qinling–Qilian– Kunlun, Qiangtang–Sanjiang, Gangdisê, Himalaya, Cathaysia, Eastern Taiwan) during the processes of oceanic crust disappearance and acceretionary-collision of continental crusts. In the orogenic belts, six convergent crustal consumption zones (Ertix–Xar Moron, South Tianshan, Kuanping–Foziling, Bangong co–Shuanghu–Nujiang–Changning–Menglian, Yarlung–Tsangpo, Jiangshao–Chenzhou–Qinfang) have been distinguished. Correspondingly, the strata of the continent of China are subdivided into 17 tectonic-strata superregions, which tectonically belong to three blocks or platforms, six convergent crustal consumption zones and eight orogenic series, respectively. This division is based mainly on differences of tectonic environment and tectonic evolution among blocks, zones and belts, including the timing of when the oceanic crusts transferred into continental crusts, the paleobiogeographic features, and the types of strata. 相似文献
2.
W. V. Preiss 《Australian Journal of Earth Sciences》2019,66(3):305-365
A series of linear to arcuate fault scarps separate the Mount Lofty Ranges from the Cenozoic St Vincent and Murray basins of South Australia. Their tectonic, sedimentary and geomorphic evolution is traced from the oldest rock record through to present-day seismicity. The scarps are the latest manifestation of repeated compressive reactivation of ancient, deep-seated crustal faults and fractures whenever the stress field was of appropriate orientation. Formation of the basins and uplift of the ranges resulted from the same processes of repeated compressive reactivation. Continental crust was intensely fractured during three episodes of Neoproterozoic–Cambrian rifting that led to the formation of the Adelaide Geosyncline and break-up of Rodinia. Neoproterozoic eastward-dipping, listric extensional faults provided accommodation space for deposition of the Burra Group. Sediments of the Umberatana and Wilpena groups were deposited under mainly sag-phase conditions. In the early Cambrian, new extensional faults formed the deeply subsident Kanmantoo Trough. Cambrian rift faults swung from east–west on Kangaroo Island through northeasterly on Fleurieu Peninsula to north–south in the easten Mount Lofty Ranges, cutting across the older meridional rifts. These two sets of extensional faults were reactivated as basement-rooted thrusts in the ensuing Delamerian Orogeny. The Willunga Fault originated as a Cambrian rift fault and was reactivated in the Delamerian Orogeny as a thrust dipping southeast under a regional basement-cored antiform on southern Fleurieu Peninsula. Much of southern Australia, including the eroded remnants of the Delamerian highlands, was covered by a continental ice sheet in the Carboniferous–Permian. The preferential preservation of glacial sediments on Fleurieu Peninsula may have resulted from extensional reactivation of the Willunga Fault, possibly in the early Mesozoic. Fleurieu Peninsula was then warped into an open, southwest-plunging antiform, spatially coincident with the much higher amplitude Delamerian antiform. Glacial sediments were eroded from uplifted (up-plunge) areas before formation of a ‘summit surface’ across deeply weathered bedrock and preserved glacial sediments in the later Mesozoic. This surface was covered with fluvial to lacustrine sediments in the middle Eocene. Neotectonic movements under a renewed compressive regime commenced with reactivation of the Willunga Fault, restricting subsequent Eocene to Miocene sedimentation to the St Vincent Basin. The Willunga scarp was onlapped in the Oligocene–Miocene concomitant with continuing uplift and formation of a hanging-wall antiform. In the late Cenozoic, repeated faulting and mild folding, angular unconformities, ferruginisation and proximal coarse sedimentation took place on various faults at different times until the late Pleistocene. 相似文献
3.
《地学前缘(英文版)》2023,14(3):101553
Eight lines of evidence indicate that the Orosirian Period in mid-Paleoproterozoic time was characterized by plate tectonics: ophiolites, low T/P metamorphism including eclogites, passive margin formation, tall mountains, paleomagnetic constraints, ore deposits, abundant S-type granites, and seismic images of paleo-subduction zones. This plate tectonic episode occurred about 1 billion years earlier than the present plate tectonic episode began in Neoproterozoic time. The two plate tectonic episodes bracket the ‘Boring Billion’, which may have been a protracted single lid tectonic episode that began when the supercontinent Nuna or Columbia formed. Recognition of multiple lines of evidence for Orosirian plate tectonics demonstrates that Earth’s tectonic style can be reconstructed with some confidence back to at least Early Paleoproterozoic time, and thus the absence of compelling evidence for Mesoproterozoic plate tectonics is not obvious due to poor preservation. A tectono-magmatic lull ～2.3 Ga suggests an earlier episode of single lid tectonics. Evidence for two episodes of plate tectonics and two episodes of single lid tectonics indicates that Earth switched between single lid and plate tectonics multiple times during the last 2.4 Ga. 相似文献
4.
Deformation patterns in subduction zones, feeder systems of volcanoes, and rifts are compared and investigated in terms of relations among elastoplastic strain, rheology, pore fluids, and temperature. Regional-scale subduction processes have been explored in segments of the Kuriles–Kamchatka, Izu-Bonin, and Mariana zones. Slab geometry constraints from the 3D velocity structure are used to model the balance of forces in the three subduction zones and to distinguish the regions of predominant push or pull. Stress and strain variations in suprasubduction crust are considered for the case of magma sources beneath the Klyuchevskoy group of volcanoes. Time-lapse (4D) seismic tomography shows crustal magma reservoirs to appear and disappear rapidly as the volcanoes become active or dormant, respectively. This behavior is due to rapid strain changes which cause fast flow of fluids and the ensuing decrease or increase of melting temperature in the magma reservoirs. In addition to subduction zones, stress–strain patterns are modeled for collisional (compressive) settings, with the example of the Altai–Sayan area and the Caucasus, and for the conditions of rifting (extension), in the case of the Vilyui basin. As the modeling shows, formation of a superdeep basin does not necessarily require the crust to stretch twice or more: only 20% stretching in the necking region is enough to produce a 10–15 km deep basin. 相似文献
5.
《International Geology Review》2012,54(12):1510-1527
ABSTRACTDevonian quartzite occurs as blocks within a phyllite matrix in Puziba area of the Mianlue Suture Zone (MLSZ) in central China. The depositional time of the quartzite is younger than 425 Ma (mainly Early Devonian), constrained by the zircon U–Pb geochronology data from the quartzite, cross-cutting relationships with granite, and palaeontology evidence. The detrital zircons in the quartzite show typical magmatic features with four main age peaks at: 2676–2420 Ma (11.6% of the population), 1791–1606 Ma (4.8%), 997–817 Ma (26.5%), and 597–425 Ma (17.5%). In combination with the zircon εHf(t) values, we propose that the quartzite in the MLSZ was sourced from Neoproterozoic and Palaeozoic magmatic and sedimentary rocks in the South Qinling Block and the South China Block (particularly from the Bikou Terrane), with minor contributions from Archaean and Palaeoproterozoic magmatic units from both of the South and North China blocks. The blocks of quartzite, slate, marble, metasandstone, and chert blocks in the phyllite matrix in the Puziba area show a typical block-in-matrix texture in a tectonic mélange, and provide significant evidence from sedimentary rock blocks rather than ophiolite or volcanic rock for the existence of the MLSZ. 相似文献
6.
The evolution of east coast of India sis discussed within the ambit of clearly identifiable four major tectonic stages which
had a profound effect in shaping the tectonic grain of the east coast basins. The evolutionary process began with rift related
crustal extension between India and Sri Lanka as a consequence of Africa-Antarctica rifting and development of Natal Basin.
An arm of this rift led to initial extension in the Cauvery Basin and failed. Later, the India-West Australia rift propagated
further in southwesterly direction initiating Mahanadi and Krishna-Godavari Basins. This extension was an oblique one with
Nayudupeta high acting as pivot. The oblique extension followed by asymmetric seafloor spreading developed transpression along
India-Sri Lanka and Antarctica junction, resulting in a NNW-SSE trending transcurrent fault along which Antarctica moved southward.
Subsequently, entire east coast evolved through a more or less uniform post rift stage. 相似文献
7.
The Southwest Indian mid-ocean ridge (SWIR) is an ultraslow spreading ridge. Based on the submarine bathymetric data, we develop a new division principle on submarine morphotectonics and subdivide the SWIR into the seven-order tectonic geomorphologic units. Taking its submarine morphotectonics in the middle segment and adjacent seafloors of the mid-ocean ridge between Discovery II and Gallieni transform faults as a sample, this paper systematically analyzes its tectonic evolution, segmentation, segmentation and propagation mechanism, the formation of the central rift valley, the ridge-plume interactions, and the ocean ridge jumping. The results showed that the mid-ocean ridges can be divided into four three-order morphotectonics units (i.e., one-order segments of mid-ocean ridge), from west to east, which are separated by the Andrew Bain, the Prince Edwards, the Discovery II, and the Gallieni transform faults, respectively, corresponding to ridge landforms associated with a strongly hotspot-affected ridge, a weakly hotspot-affected ridge, and a normal ultraslow spreading ridge. Each segment can be further subdivided into three or four secondary segments. This paper focuses only on the segmentation and division from fourth-order to seventh-order morphotectonics units between the Discovery II and the Gallieni transform faults (i.e., the fourth-order morphotectonics unit of mid-ocean ridges can be subdivided into other three secondary units). Here the seventh-order morphotectonics unit consists of segments of laterally-aligned rifts (shear zone), en echelon rifts, and other transverse-faulting structures. The mid-ocean ridge segment experienced three oceanic ridge jumping at about 80 Ma, 60 Ma and 40 Ma, respectively, which were affected by the Marion and Crozet hotspots, or the Madagascar Plateau, etc. The oceanic processes of the SWIR are related to the Gondwana breakup, and its tectonic processes has been analyzed in detail as the periodic pull-apart extension, domino-style half-graben, graben subsidence, oceanic core complex, etc. in axial mid-oceanic ridge since 20 Ma. ©, 2015, Science Press. All right reserved. 相似文献
8.
Variations in the O, Sr, Nd, and Hf isotopic compositions in rocks of various ages, minerals, and mantle temperature in the geological history are considered. Two periods in the Earth’s history are studied: the beginning of the formation of the planet until the turn of (3.4) 2.7–2.5 Ga and the tectonic movement period in the last 2 Ga, and also the transitional period within 2.7–2.0 Ga. 相似文献
9.
Dong Yu Wang SiMiao Yu Qian Chen JingSheng Yang Hao Ge WenChun Bi JunHui Jing JiaHao 《岩石学报》2022,(8):2249-+
Northeastern China is suited in the eastern part of the Central Asian Orogenic Belt, and it is mainly composed of Erguna Massif, Xing'an Massif, Songnen-Zhangguangcai Range Massif, Jiamusi Massif, and Nadanhada Terrane. The Late Paleozoic magmatism was relatively intense accompanied with multiple stages of amalgamation in several microcontinents, therefore these magmatic products are an important media in recording the Late Paleozoic tectonic evolution history of the northeastern China. According to the petrological, geochronological, and geochemical characteristics of Late Paleozoic igneous rocks in the northeastern China, we found that the Late Paleozoic magmatism was based on Carboniferous -Permian igneous rocks. The Early Carboniferous magmatic products are gabbro, diorite and granite, the Late Carboniferous magmatic products are mainly composed of granitoids with minor gabbro, and the Permian magmatic products are mainly granitoids. Meanwhile, these Late Paleozoic igneous rocks mostly exhibit typical arc characteristics. In addition, the Late Paleozoic igneous rocks in eastern Jilin and Heilongjiang provinces are mainly Permian granitoids with minor gabbro, and these Permian igneous rocks show typical arc characteristics. Combined with petrological, geochronological, geochemical and isotopic characteristics, we suggest that the Late Paleozoic igneous rocks in the Great Xing'an Range and eastern Jilin and Heilongjiang provinces underwent different magmatic evolution history, and the microcontinents in NE China had different crustal growth history. 相似文献
10.
The geology of Northern Vietnam offers critical clues on the convergence history between the South China and Indochina blocks. We constrain the tectonic evolution of the South China and Indochina blocks using geochemical, mineral chemical and geochronological data collected from mafic–ultramafic rocks exposed in the Cao Bang area, Northeastern Vietnam. These rocks show significant enrichment in large ionic lithophile elements (LILEs) such as Cs, Rb, Ba, Th, U, and Pb and depletion in high field strength elements (HFSEs) such as Nb, Ta, Zr, and Ti showing [Nb/La]N between 0.28–0.41, [La/Yb]N = 3.94–10.00 and Zr/Y = 2.0–4.4. These geochemical features as well as the petrology and mineral chemistry of the Cao Bang mafic–ultramafic magmas are comparable to those of magmatic complexes formed in a back-arc environment. The basalts yield Rb–Sr whole rock ages of 263 ± 15 Ma, that are consistent with the zircon U–Pb and K–Ar ages reported in previous studies from the same area. The spatial and temporal distribution of the arc magmas within the Indochina block and along the southern margin of the South China block suggest that the Permo-Triassic mafic–ultramafic magmas formed during a tectonic event that is different from the subduction and collision event between the Indochina and South China blocks. 相似文献
11.
Analysis of the Upper Cretaceous stratigraphy of the Peel Block reveals the basin development of the block to have been influenced by both the inversion of the Roer Valley Graben and Central Netherlands Basin, and the overall Late Cretaceous transgression. Sediments of Santonian to Danian age were deposited on the block. These sediments are compared with the detailed lithostratigraphy of southern Limburg, where Late Cretaceous strata are exposed. Four successions can be recognised in southern Limburg. The two oldest successions, the Santonian Oploo Formation (new name, proposed in the present contribution) and the mainly Early Campanian Vaals Formation, are restricted to the central and northern parts of the block. These siliciclastic formations were deposited under the influence of inversion of the Roer Valley Graben and the Central Netherlands Basin, as well as under the influence of a rising sea level. Towards the north, sands of the Oploo Formation grade into marls and chalks of the Ommelanden Formation. The two youngest successions comprise the largely Late Campanian to Maastrichtian Gulpen and Maastricht Formations and the Danian Houthem Formation. These chalk formations were deposited under the influence of regional subsidence during a sea-level highstand. Subsequent to deposition of the Houthem Formation, a regional regression triggered a change from shallow-marine carbonate to paralic siliciclastic deposition. 相似文献
12.
13.
增生造山带中陆源碎屑岩物源区特征的研究可为解剖造山带结构甚至大陆地壳的形成和演化提供关键证据。北山造山带中部的古硐井群被认为是前寒武纪稳定沉积盖层,是北山造山带存在微陆块的重要依据。本文围绕古硐井群的物源区特征,进行了碎屑颗粒和重矿物统计、全岩主微量元素地球化学分析、碎屑锆石U-Pb年代学和Hf同位素测试。古硐井群碎屑岩的碎屑颗粒多呈棱角状,主要为石英、长石,同时含大量硅质岩碎屑和一定数量的火山岩碎屑;重矿物组成以褐铁矿、锆石、白钛石、尖晶石为主,角闪石、电气石、辉石次之,暗示物源区可能存在蛇绿岩、增生杂岩。全岩主量元素以高硅、高铝、富碱、低锰为特征,结合REE、Cr、Co、Sc和Th等惰性元素含量特征共同指示了长英质的物源区。最年轻的碎屑锆石年龄为443.9±13Ma,表明古硐井群最大沉积时限为晚奥陶世。碎屑锆石的年龄高度集中于470Ma附近,且该区间锆石εHf(t)值多为正值,指示物源区存在大量新生地壳物质。本文推测古硐井群可能形成于增生楔楔顶盆地;研究结果支持北山造山带是古生代持续增生造山的产物这一认识。 相似文献
14.
E. G. Ivolga V. G. Gurovich N. P. Romanovsky Yu. O. Manilov 《Russian Journal of Pacific Geology》2016,10(5):351-364
Petrophysical characteristics are determined for the rock complexes of the Okhotsk margin within the continent–ocean transition zone. Petrophysical maps showing the major inhomogeneities of the main tectonic elements of the studied area are constructed. Petrophysical inhomogeneities and the corresponding geophysical field anomalies are compared. A relationship between the magnetic field anomalies and subsurface rock complexes is revealed. The gravity field anomalies are related to deep inhomogeneities and are almost independent of the subsurface rock complexes of relatively low thickness. 相似文献
15.
Richard J. Goldfarb 《Mineralium Deposita》2013,48(4):543-544
16.
《Journal of Structural Geology》1999,21(8-9):1125-1130
Integrated studies that correlate gravity data with magmatic structures or geochemical analysis reveal that the organization of granitic plutons (shape and feeder) varies according to the tectonic regime (brittle or ductile) and type (extension, strike-slip or compression) under which magma was generated. Deformation clearly controls granite emplacement. It also has influence during the ascent, segregation of melt and indirectly during the phase of initial melting. Because of the contrast of viscosity between melt and its plastic matrix, strain partitioning develops during magma ascent that facilitates melt flow, which bears consequences for the chemical evolution of the magma. Fast rate of melt extraction out of the source may lead to chemical disequilibrium. At a larger scale, petrochemical zoning of plutons is described as a dynamic process that results from the competition between the rate of magma emplacement (the rate of the room provided by deformation) and the rate of magma delivery. 相似文献
17.
This paper reports the results of field observation and the study of coastal tectonic deformations related to the Nevelsk tsunamigenic earthquake (August 2, 2007, M ～ 6.1) obtained in August-September of 2007. The earthquake caused a 0.5- to 1.5-m rise of and partial desiccation of the southern, central, and northern benches and the formation of longitudinal structural ridges seaward of Lovetskaya Bay. In the framework of the new model of the Kamyshovy (West Sakhalin) Anticlinorum as a structure of the Quaternary and Middle Quaternary crustal detachment, the relationships between the earthquake and the slow gravitational creep of the upper crust on its western slope with local squeezing of the Middle Miocene Nevelsk siltstones are discussed. 相似文献
18.
Newly discovered mud volcanoes in the Coastal Belt of Makran,Pakistan—tectonic implications 总被引：1，自引：1，他引：0
Akhtar M. Kassi Shuhab D. Khan Huseyin Bayraktar Aimal K. Kasi 《Arabian Journal of Geosciences》2014,7(11):4899-4909
The Makran accretionary wedge has a much larger number of mud volcanoes then those reported earlier. Using high-resolution satellite images, over 70 active mud volcanoes were identified. These mud volcanoes occur within a well-defined zone; we call it the Makran zone of active mud volcanoes (MZAMV), which is parallel to the regional trend of the accretionary wedge. Mud volcanoes within the zone occur as clusters, which form linear belts parallel to the regional thrusts associated with anticlines. The MZAMV zone also includes the offshore mud volcanoes occurring in the shallow shelf area, including the recurrently emerging mud islands. Several occurrences of thick deposits of old mud volcanoes (Pleistocene or even older) are also present within this zone, which also display recognizable features that are characteristic of the fossil mud volcanoes. We propose that the MZAMV developed and evolved in response to the continued compression within the Makran accretionary wedge, which in turn, is a response of the subduction process. Mud diapirism has been an ongoing phenomena since Pleistocene or even earlier. The events of enhanced mud extrusion in mud volcanoes and/or emergence of island(s) have relevance with seismic phenomena and, therefore, may be closely monitored. 相似文献
19.
《International Geology Review》2012,54(4):508-528
The nature of the Namco–Renco ophiolites in the northern Lhasa subterrane is widely disputed. To investigate their formation age, petrogenesis, and tectonic setting, the harzburgites, basalts, and metagabbros of the Namco ophiolite and the harzburgites, lherzolites, gabbros, and diabasic dikes of the Renco ophiolite were selected for whole-rock geochemical and zircon U-Pb dating and in situ Lu-Hf isotopic analyses. The geochemical and geochronological data indicate that the Namco metagabbros were generated at 178.0 ± 2.9 Ma, along with the Namco–Renco peridotites formed in the initial stage of a continental margin basin; whereas the Renco gabbros were developed at 149.7 ± 1.6 Ma, along with the Renco diabasic dikes and Namco basalts formed later in a mature back-arc basin. The Namco–Renco ophiolites were derived from a depleted mantle source with involvement of minor older crustal materials. Combined with the regional geological background, the Namco–Renco ophiolites were likely formed mainly associated with the southward subduction of the Bangong–Nujiang oceanic lithosphere beneath the Lhasa terrane. This study provides new constraints on the formation ages of the Namco–Renco ophiolites and the tectonic evolution of the Namco–Renco Ocean. 相似文献