期刊文献+
共找到22篇文章
< 1 2 >
每页显示 20 50 100
Contrasted continental rifting via plume-craton interaction: Applications to Central East African Rift 被引量:4
1
作者 Alexander Koptev Evgueni Burov +4 位作者 Eric Calais Sylvie Leroy Taras Gerya Laurent Guillou-Frottier Sierd Cloetingh 《Geoscience Frontiers》 SCIE CAS CSCD 2016年第2期221-236,共16页
The East African Rift system (EARS) provides a unique system with the juxtaposition of two contrasting yet simultaneously formed rift branches, the eastern, magma-rich, and the western, magma-poor, on either sides o... The East African Rift system (EARS) provides a unique system with the juxtaposition of two contrasting yet simultaneously formed rift branches, the eastern, magma-rich, and the western, magma-poor, on either sides of the old thick Tanzanian craton embedded in a younger lithosphere. Data on the pre-rifr, syn-rift and post-rift far-field volcanic and tectonic activity show that the EARS formed in the context of the interaction between a deep mantle plume and a horizontally and vertically heterogeneous lithosphere under far-field tectonic extension. We bring quantitative insights into this evolution by implementing high-resolution 3D thermo-mechanical numerical deformation models of a lithosphere of realistic rheology. The models focus on the central part of the EARS. We explore scenarios of plumelithosphere interaction with plumes of various size and initial position rising beneath a tectonically pre-stretched lithosphere. We test the impact of the inherited rheological discontinuities (suture zones) along the craton borders, of the rheological structure, of lithosphere plate thickness variations, and of physical and mechanical contrasts between the craton and the embedding lithosphere. Our experiments indicate that the ascending plume material is deflected by the cratonic keel and preferentially channeled along one of its sides, leading to the formation of a large rift zone along the eastern side of the craton, with significant magmatic activity and substantial melt amount derived from the mantle plume material. We show that the observed asymmetry of the central EARS, with coeval amagmatic (western) and magmatic (eastern) branches, can be explained by the splitting of warm material rising from a broad plume head whose initial position is slightly shifted to the eastern side of the craton. In that case, neither a mechanical weakness of the contact between the craton and the embedding lithosphere nor the presence of second plume are required to produce simulations that match observations. This result reconciles the passive and active rift models and demonstrates the possibility of development of both magmatic and amagmatic rifts in identical geotectonic environments. 展开更多
关键词 Plume-lithosphere interaction continental rifting East African Rift System 3D numerical modeling
下载PDF
Iteration and evaluation of shale oil development technology for continental rift lake basins
2
作者 SUN Huanquan WANG Haitao +8 位作者 YANG Yong LYU Qi ZHANG Feng LIU Zupeng LYU Jing CHEN Tiancheng JIANG Tingxue ZHAO Peirong WU Shicheng 《Petroleum Exploration and Development》 SCIE 2024年第4期993-1008,共16页
By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and develop... By benchmarking with the iteration of drilling technology,fracturing technology and well placement mode for shale oil and gas development in the United States and considering the geological characteristics and development difficulties of shale oil in the Jiyang continental rift lake basin,East China,the development technology system suitable for the geological characteristics of shale oil in continental rift lake basins has been primarily formed through innovation and iteration of the development,drilling and fracturing technologies.The technology system supports the rapid growth of shale oil production and reduces the development investment cost.By comparing it with the shale oil development technology in the United States,the prospect of the shale oil development technology iteration in continental rift lake basins is proposed.It is suggested to continuously strengthen the overall three-dimensional development,improve the precision level of engineering technology,upgrade the engineering technical indicator system,accelerate the intelligent optimization of engineering equipment,explore the application of complex structure wells,form a whole-process integrated quality management system from design to implementation,and constantly innovate the concept and technology of shale oil development,so as to promote the realization of extensive,beneficial and high-quality development of shale oil in continental rift lake basins. 展开更多
关键词 shale oil continental rift lake basin Jiyang Depression DRILLING FRACTURING DEVELOPMENT technology iteration PROSPECT
下载PDF
Thermo-Rheological Structure and Passive Continental Margin Rifting in the Qiongdongnan Basin, South China Sea, China
3
作者 LI Chaoyang JIANG Xiaodian GONG Wei 《Journal of Ocean University of China》 SCIE CAS CSCD 2022年第2期347-360,共14页
To investigate the thermo-rheological structure and passive continental margin rifting in the Qiongdongnan Basin(QDNB),thermo-rheological models of two profiles across the western and eastern QDNB are presented.The co... To investigate the thermo-rheological structure and passive continental margin rifting in the Qiongdongnan Basin(QDNB),thermo-rheological models of two profiles across the western and eastern QDNB are presented.The continental shelf of western QDNB,having the lowest crustal extension factor,is recognized as the initial non-uniform extension crust model.This regime is referred to as the jelly sandwich-1(JS-1)regime,having a lower crustal ductile layer.The oceanward part of the western QDNB changes from the relatively strong JS-1 to the weak crème brûlée-1(CB-1)regime with a significantly thinned lower crust.However,the crustal extension in the eastern QDNB is significantly higher than that in the western QDNB,with conjugate faults extending deep into the lower crust.The central depression zone of the eastern QDNB is defined as the much stronger JS-2 regime,having a brittle deformation across the entire crust and upper mantle and characteristics of a cold and rigid oceanic crust.Unlike the widespread lower crustal high-velocity layers(HVLs)in the northern margin of the South China Sea,the HVLs are confined to the lower crustal base of the central depression zone of the QDNB.The HVLs of QDNB are the results of non-uniform extension with mantle underplating during the lower crustal-necking stage,which is facilitated by the lower crustal ductile layer and derived by mantle lat-eral flowing.The gigantic mantle low-velocity zone related to the Red River Fault should be a necessary factor for the east-west differential margin rifting process of QDNB,which may drive the lateral flowing in the mantle. 展开更多
关键词 Qiongdongnan Basin thermo-rheological structure continental margin rifting high-velocity layer
下载PDF
Geochemical and Petrological Insights into the Neoproterozoic Moumba Metabasites: Implications for Crustal Processes in the West Congo Belt (Republic of Congo)
4
作者 Ulrich Verne Matiaba-Bazika Nelson Lekeba Makamba +3 位作者 Vicky Tendresse Télange Bouénitéla Nicy Carmelle Bazebizonza Tchiguina Timothée Miyouna Florent Boudzoumou 《Journal of Geoscience and Environment Protection》 2024年第2期1-29,共29页
The West Congo Belt contains in its rocks of Neoproterozoic age from Nemba complex outcropping in the Moumba River. This West Congo belt is made up of a crustal segment of the Arcuaï-West Congo orogen which exten... The West Congo Belt contains in its rocks of Neoproterozoic age from Nemba complex outcropping in the Moumba River. This West Congo belt is made up of a crustal segment of the Arcuaï-West Congo orogen which extends from southwest Gabon to the northeast of Angola. This study aims to constrain the geochemical signature Nemba complex of West Congo belt from the petrograhic and geochemical study on the whole rock. The petrographic data from this study show the Moumba metabasites are made up of amphibolites, metagabbros, epidotites and greenschists interstratified in the Eburnean metasediments and affected by mesozonal to epizonal metamorphism characterized by the retromorphosis of intermediate amphibolite facies minerals into greenschist facies. Whole-rock geochemical data indicate that these metabasites are continental flood basalts (CFB) of basic nature and transitional affinity emplaced in intraplate context. These continental flood basalts are generated from magma originating from a significantly enriched shallow mantle plume and this magma then contaminated by the continental crust during their ascent. The reconstruction of tectonic signature suggests that West Congo belt would result from closure of an ocean basin with subduction phenomena. This collision would be marked by the establishment of ophiolite complex. We show that this model is incompatible with the CFB nature of metabasites and the orogenic evolution of Neoproterozoic. It does not seem that we can evoke a genetic link with a subduction of oceanic crust, because the paleogeography of Neoproterozoic (Rodinia) is marked by intracontinental rifts linked to opening of Rodinia. We therefore suggest the non-existence of ophiolitic complex in western Congo belt and reject the collisional model published by certain authors. We confirm the currently available intracontinental orogen model. 展开更多
关键词 Mayombe METABASITES Moumba Mantle Plume continental rifting Basalts Flood continental
下载PDF
Mid—Late Neoproterozoic rift-related volcanic rocks in China:Geological records of rifting and break-up of Rodinia 被引量:22
5
作者 Linqi Xia Zuchun Xia Xueyi Xu Xiangmin Li Zhongping Ma 《Geoscience Frontiers》 SCIE CAS 2012年第4期375-399,共25页
Early Cambrian and Mid--Late Neoproterozoic volcanic rocks in China are widespread on several Precambrian continental blocks, which had aggregated to form part of the Rodinia supercon- tinent by ca. 900 Ma. On the bas... Early Cambrian and Mid--Late Neoproterozoic volcanic rocks in China are widespread on several Precambrian continental blocks, which had aggregated to form part of the Rodinia supercon- tinent by ca. 900 Ma. On the basis of petrogeochemical data, the basic lavas can be classified into two major magma types: HT (Ti/Y 〉 500) and LT (Ti/Y 〈 500) that can be further divided into HT1 (Nb/La 〉 0.85) and HT2 (Nb/La ≤ 0.85), and LT1 (Nb/La 〉 0.85) and LT2 (Nb/La ≤ 0.85) subtypes, respectively. The geochemical variation of the HT2 and LT2 lavas can be accounted for by lithospheric contamination of asthenosphere- (or plume-) derived magmas, whereas the parental magmas of the HT1 and LT1 lavas did not undergo, during their ascent, pronounced lithospheric contamination. These volcanics exhibit at least three characteristics: (1) most have a compositional bimodality; (2) they were formed in an intracontinental rift setting; and (3) they are genetically linked with mantle plumes or a mantle surperplume. This rift-related volcanism at end of the Mid-- Neoproterozoic and Early Cambrian coincided temporally with the separation between Australia-- East Antarctica, South China and Laurentia and between Australia and Tarim, respectively. 展开更多
关键词 NEOPROTEROZOIC Bimodal volcanism continental rift Mantle plume Rodinia supercontinent China
下载PDF
Tectonic characteristics and structural styles of a continental rifted basin:Revelation from deep seismic reflection profiles 被引量:1
6
作者 Yuan Li Yannan Zhao +1 位作者 Zhengliang Lin Qinlin Ma 《Geodesy and Geodynamics》 2016年第5期329-339,共11页
The Fushan Depression is a half-graben rifted sub-basin located in the southeast of the Beibuwan Basin, South China Sea. The Paleogene Liushagang sequence is the main hydrocarbon-bearing stratigraphic unit in the sub-... The Fushan Depression is a half-graben rifted sub-basin located in the southeast of the Beibuwan Basin, South China Sea. The Paleogene Liushagang sequence is the main hydrocarbon-bearing stratigraphic unit in the sub-basin. Using three-dimensional(3-D)seismic data and logging data over the sub-basin, we analyzed structural styles and sedimentary characteristics of the Liushagang sequence. Five types of structural styles were defined: ancient horst, traditional slope, flexure slope-break, faulted slope-break and multiple-stage faults slope, and interpretations for positions, background and development formations of each structural style were discussed. Structural framework across the sub-basin reveals that the most remarkable tectonic setting is represented by the central transfer zone(CTZ) which divides the sub-basin into two independent depressions, and two kinds of sequence architectures are summarized:(i) the western multi-stage faults slope;(ii) the eastern flexure slope break belt. Combined with regional stress field of the Fushan Depression, we got plane combinations of the faults, and finally built up plan distribution maps of structural system for main sequence. Also, we discussed the controlling factors mainly focused on subsidence history and background tectonic activities such as volcanic activity and earthquakes. The analysis of structural styles and tectonic evolution provides strong theoretical support for future prospecting in the Fushan subbasin and other similar rifted basins of the Beibuwan Basin in South China Sea. 展开更多
关键词 South China Sea continental rifted basin Structural style 3-D seismic-reflection Seismic geomorphology
原文传递
Tectonic Nature of the Northern Segment of the Jiao-Liao-Ji Belt:A Rift or Continental Collision Belt? 被引量:1
7
作者 MENG En WANG Chaoyang +3 位作者 LI Yanguang CAI Jia YANG Hong LI Zhuang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第3期1159-1160,共2页
Objective The tectonic characteristics and evolution of the Paleoproterozoic Jiao-Liao-Ji belt have been extensively studied in recent decades (Fig. 1 a). Two main models have been proposed for the formation of this... Objective The tectonic characteristics and evolution of the Paleoproterozoic Jiao-Liao-Ji belt have been extensively studied in recent decades (Fig. 1 a). Two main models have been proposed for the formation of this belt: a continental-or arc-continent collisional belt, and the opening and closure of an intra-continental rift. The main reasons for these ongoing debates are own to the complex composition, including metamorphosed volcano-sedimentary rocks, multiple pulses of granitic magmatism, meta-mafic intrusions, and tectono- metamorphic history. In addition, earlier work focused on the geochronology and metamorphic evolution, whereas the source properties, petrogenesis, and tectonic setting of the metamorphosed volcano-sedimentary sequence and meta- mafic intrusions are poorly understood. 展开更多
关键词 of in as with Ga Tectonic Nature of the Northern Segment of the Jiao-Liao-Ji Belt:A Rift or continental Collision Belt were meta or
下载PDF
Sequence boundaries and regularities in the oil-gas distribution of the low swelling slope belt in the continental rift basin 被引量:3
8
作者 Xie Zongkui 《Mining Science and Technology》 EI CAS 2011年第3期419-425,共7页
Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problem... Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problems to be solved during exploration of a region. Taking the Paleogene system developed along the east slope belt of Chengdao as an example the concepts of sequence stratigraphy and sedimentary sequenc are applied. A new research method likened to a way ''to get a melon by following the vine'' is proposed to determine the direction for exploring within un-drilled or less-drilled areas. This is the process: ''the characteristics of the sequence boundary ? the forming mechanism of the stratigraphic sequence ? the conditions of oil and gas accumulation ? the distribution zones of oil and gas''. The relationship between the dynamic mechanism of stratigraphic sequence and the forming conditions for oil and gas accumulation establishes that the tectonic disturbance of the slope belt has significant responses as denudation and deposition. Above the stratigraphic sequence boundary there are large scale sand bodies of the low stand system tract (LST) that have developed in the low swelling slope belt and its deep depression. Below the sequence boundary there are the remaining sand bodies of the high stand system tract (HST). On the slope there is a convergence of mudstone layers of the extended system tract (EST) with the mudstone of the underlying strata, which constitutes the screening conditions for the reservoir of the down slope and deep depression. The distribution regularities in preferred sand bodies on the surface of the sequence boundary, and in the system tract, indicate the ordering of oil-gas deposits. From the higher stand down to the depth of the slope there are, in order, areas where exploration was unfavorable, major areas of stratigraphic overlap of oil-gas reservoirs, unconformity screened oil-gas reservoirs, and, finally, sandstone lens oil-gas reservoirs. The low swelling slope belt of Chengdao was tectonically active, which is typical for a continental rift basin. The methodology and results of the present paper are significant for the theory and practice of predicting subtle reservoir and selecting strategic areas for exploration. 展开更多
关键词 continental rift basinLow swelling ChengdaoSequence boundary Subtle reservoirThe distribution regularity of oil and gas
下载PDF
Occurrence of Laminated Dolomitic Exhalative Rocks in Continental Rift Basins of Northwest China
9
作者 WEN Huaguo LUO Lianchao +2 位作者 ZHENG Rongcai Hairuo QING XU Wenli 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第5期1934-1935,共2页
Objective Researchers have recently discovered that sublacustrine sedimentary exhalative mechanism associated with volcanism,is the principle way to form lacustrine exhalative rocks.These rocks differentiate themselve... Objective Researchers have recently discovered that sublacustrine sedimentary exhalative mechanism associated with volcanism,is the principle way to form lacustrine exhalative rocks.These rocks differentiate themselves from normal sedimentary rocks in their specificpetrofabric and material composition. 展开更多
关键词 Occurrence of Laminated Dolomitic Exhalative Rocks in continental Rift Basins of Northwest China REE
下载PDF
Tectonic Related Lithium Deposits Another Major Region Found North East Tanzania—A New Area with Close Association to the Dominant Areas: The Fourth of Four 被引量:1
10
作者 Lawrence Stephenson 《Natural Resources》 2023年第9期161-191,共31页
The current “mega” interest in Lithium resources was spurred by the development of Lithium-Ion batteries to aid in restructuring the world’s reliance on carbon spewing power petroleum reserves. Current resources of... The current “mega” interest in Lithium resources was spurred by the development of Lithium-Ion batteries to aid in restructuring the world’s reliance on carbon spewing power petroleum reserves. Current resources of lithium recovery have fallen into two main categories—Pegmatite, found worldwide associated with felsic intrusions and Brine Related, and now with development in the Southwest United States of America (SWUS), a third category— Tertiary Volcanic clays, are specifically associated with Tertiary volcanics and major Tectonic Plate interactions. “Active” Plate tectonics is important as both the SWUS, the Lithium Triangle of South America (LTSA) and the Tibetan Plateau of China (TPC) producing tertiary (Miocene) volcanism that is important to the development of Lithium resources. The Tanzanian part of the East Africa Rift System (EARS) has features of both the SWUS, tertiary volcanic related “playas” and Continental rifting, the LTSA, tertiary volcanic related “Brines” and a major Tectonic plate event (subduction of an Oceanic Plate beneath the Continental South American Plate) and the TPC, tertiary volcanics (?) and major tectonic plate event (subduction of the Indian Continental Plate under the Eurasian Continental Plate). As well as the association of peralkaline and metaluminous felsic volcanics with Lithium playas of the SWUS and the EARS (Tanzania) “playas”. These similarities led to an analysis of a volcanic rock in Northeast Tanzania. When it returned 1.76% Lithium, a one-kilometer spaced soil sampling program returned, in consecutive samples over 0.20% Lithium (several samples over 1.0% lithium and a high of 2.24% lithium). It is proposed that these four regions with very similar past and present geologic characteristics, occur nowhere else in the world. That three of them have produced Lithium operations and two of them have identified resources of Lithium clay and “highly” anomalous Lithium clays should be regarded as more than “coincidental”. 展开更多
关键词 Lithium Triangle of South America Southwest United States Tibetan Plateau of China East Africa Rift System Tectonic continental Oceanic Plate Subduction Tertiary (Miocene - Holocene) Volcanics continental rifting
下载PDF
Influence of mantle plume on continental rift evolution:A case study of the East African rift system
11
作者 Haixuan Xu Jianghai Li +2 位作者 Lijie Wang Xiaoyu Zhang Bo Feng 《Petroleum Research》 EI 2024年第3期409-417,共9页
Mantle plume is an essential component of the mantle convection system,and its influence on the geodynamics of continental rifts is of great significance for understanding the crust–mantle interaction.The East Africa... Mantle plume is an essential component of the mantle convection system,and its influence on the geodynamics of continental rifts is of great significance for understanding the crust–mantle interaction.The East African Rift System,as the largest continental rift in the Cenozoic and in the initial stage,provides an excellent option for studying the interaction between the mantle plume and the continental crust.Based on the data such as GPS,seismic tomography,and global crustal model,a viscoelastic-plastic 2D thermodynamic numerical model is established to reconstruct the evolution of the Afar depression,Ethiopian Rift,and Kenyan Rift.By comparing the differences between the models of the Afar depression,Ethiopian Rift,and Kenyan Rift,the relationship between the mantle plume and pre-existing structures and their influence on the evolution of continental rifts are discussed.The results show that the mantle plume can increase the depth of the rift faults,concentrate the distribution of the faults,and strengthen the control of main faults on the rifts,allowing the possibility of narrow rifts.Pre-existing structures control the fault styles and symmetry of the rifts and also the morphology of the mantle plume. 展开更多
关键词 Mantle plume continental rift East Africa rift system Numerical simulation
原文传递
Cenozoic tectono-sedimentary characteristics and extension model of the Northwest Sub-basin,South China Sea 被引量:8
12
作者 Weiwei Ding Mingbi Li +2 位作者 Lihong Zhao Aiguo Ruan Zhenli Wu 《Geoscience Frontiers》 SCIE CAS 2011年第4期509-517,共9页
Based on the interpretations of three seismic profiles and one wide-angle seismic profile across the Northwest Sub-basin,South China Sea.stratigraphic sequences,deformation characteristics and an extension model for t... Based on the interpretations of three seismic profiles and one wide-angle seismic profile across the Northwest Sub-basin,South China Sea.stratigraphic sequences,deformation characteristics and an extension model for this sub-basin have been worked out.Three tectonic-stratigraphic units are determined.Detailed analyses of extension show that the event occurred mainly during the Paleogene and resulted in the formation of half-grabens or grabens distributed symmetrically around the spreading center.Sediments are characterized by chaotic and discontinuous reflectors,indicating clastic sediments. Farther to the southwest,the sub-basin features mainly continental rifting instead of sea-floor spreading. The rifting would have been controlled by the shape of the massif and developed just along the northern edge of the Zhongsha-Xisha Block,rather than joined the Xisha Trough.After 25 Ma.a southward ridge jump triggered the opening of the Southwest Sub-basin.The NW-directed stress caused by the sea-floor spreading of the Northwest Sub-basin may have prevented the continuous opening of the sub-basin.After that the Northwest Sub-basin experienced thermal cooling and exhibited broad subsidence.The deep crustal structure shown by the velocity model from a wide-angle seismic profile is also symmetrical around the spreading center,which indicates that the Northwest Sub-basin might have opened in a pure shear model. 展开更多
关键词 continental rifting CENOZOIC Tectono-sedimentary characteristics Extension model Northwest Sub-basin Marginal sea
下载PDF
Neoproterozoic–Early Paleozoic Tectonic Evolution of the South China Craton: New Insights from the Polyphase Deformation in the Southwestern Jiangnan Orogen 被引量:12
13
作者 ZHAO Zhongbao XU Zhiqin +2 位作者 MA Xuxuan LIANG Fenghua GUO Peng 《Acta Geologica Sinica(English Edition)》 CAS CSCD 2018年第5期1700-1727,共28页
A 〉1500–km–long northeast–southwest trending Neoproterozoic metamorphic belt in the South China Craton(SCC) consists of subduction mélange and extensional basin deposits. This belt is present under an uncon... A 〉1500–km–long northeast–southwest trending Neoproterozoic metamorphic belt in the South China Craton(SCC) consists of subduction mélange and extensional basin deposits. This belt is present under an unconformity of Devonian–Carboniferous sediments. Tectonic evolution of the Neoproterozoic rocks is crucial to determining the geology of the SCC and further influences the reconstruction of the Rodinia supercontinent. A subduction mélange unit enclosed ca.1000–850–Ma mafic blocks, which defined a Neoproterozoic ocean that existed within the SCC, is exposed at the bottom of the Jiangnan Orogen(JO) and experienced at least two phases deformation. Combined with new(detrital) zircon U–Pb ages from metasandstones, as well as igneous rocks within the metamorphic belt, we restrict the strongly deformed subduction mélange as younger than the minimum detrital age ca. 835 Ma and older than the ca. 815 Ma intruded granite. Unconformably overlying the subduction mélange and the intruded granite, an intra–continental rift basin developed 〈800 Ma that involved abundant mantle inputs, such as mafic dikes. This stratum only experienced one main phase deformation. According to our white mica ^40Ar/^(30)Ar data and previously documented thermochronology, both the Neoproterozoic mélange and younger strata were exhumed by a 490–400–Ma crustal–scale positive flower structure. This orogenic event probably induced the thick–skinned structures and was accompanied by crustal thickening, metamorphism and magmatism and led to the closure of the pre–existing rift basin. Integrating previously published data and our new results, we agree that the SCC was located on the periphery of the Rodinia supercontinent from the Neoproterozic until the Ordovician. Furthermore, we prefer that the convergence and dispersal of the SCC were primarily controlled by oceanic subduction forces that occurred within or periphery of the SCC. 展开更多
关键词 Rodinia supercontinent South China Craton Jiangnan Orogen intra–continental rifting intra–continental orogen
下载PDF
A Global Perspective on Crustal Structure and Evolution based on A New Crustal Classification
14
作者 Irina M.ARTEMIEVA Alexey SHULGIN 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2021年第S01期48-50,共3页
Knowledge of the crustal structure is the key for understanding physical and chemical conditions of its formation and later modification by geodynamic processes.It has long been recognized that crustal structure is co... Knowledge of the crustal structure is the key for understanding physical and chemical conditions of its formation and later modification by geodynamic processes.It has long been recognized that crustal structure is controlled by tectonic settings,and that the crustal thickness is one of the most important parameters that reflects the geodynamic origin of the crust.A long tectonic life of continental crust leads to its significant reworking by plate tectonics processes and crust-mantle interaction,which include mechanical extension. 展开更多
关键词 crustal delamination granitization basin subsidence orogenic processes continental rifting HOTSPOTS continental shelves failed oceans oceanic crust
下载PDF
The abnormal mantle and deep tectonic process in the southern region of North China Plain
15
作者 高世玉 胡鸿翔 丁山 《Earthquake Science》 CSCD 1994年第S1期61-69,共9页
In this paper, based on the large scale uplift, lateral inhomogeneity and low interface velocity along the Moho as well as the soft low velocity layer under it obtained from deep seismic sounding (DSS), we deduced tha... In this paper, based on the large scale uplift, lateral inhomogeneity and low interface velocity along the Moho as well as the soft low velocity layer under it obtained from deep seismic sounding (DSS), we deduced that the southern region of North China Plain is characterized by continental rift and abnormal mantle in the lithosphere.Summarizing geological and geophysical data, we try to state that the forming and developing of abnormal mantle and the intermittent activity of asthenosphere are the dynamic sources to dominate the geologic structure and tectonic movement in this region. We also point out that the research of deep process is important to probe timespace law of earthquake occurrence. 展开更多
关键词 North China Plain abnormal mantle continental rifting vertical tectonic movement SEISMICITY
下载PDF
Geochronological and geochemical constraints on the petrogenesis of late Mesoproterozoic mafic and granitic rocks in the southwestern Yangtze Block 被引量:4
16
作者 Guichun Liu Jing Li +4 位作者 Xin Qian Qinglai Feng Wei Wang Guangyan Chen Shaobin Hu 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第1期39-52,共14页
Late Mesoproterozoic igneous rocks in the SW Yangtze Block are important for understanding the role of it in reconstruction of the Rodinia supercontinent.In the present study,we report new geochronological,geochemical... Late Mesoproterozoic igneous rocks in the SW Yangtze Block are important for understanding the role of it in reconstruction of the Rodinia supercontinent.In the present study,we report new geochronological,geochemical,and Nd-Hf isotopic data for the Cuoke plagioclase amphibolites and granites in the SW Yangtze Block.Geochronological results show that the plagioclase amphibolites and granites have similar late Mesoproterozoic zircon U-Pb ages of 1168-1162 Ma,constituting a bimodal igneous assemblage.The plagioclase amphibolites have high and variable TiO2 contents(1.15-4.30 wt.%)and Mg#(34-66)values,similar to the tholeiitic series.They are characterized by enrichment in LREEs and LILEs,and have OIB-like affinities with positive Nb and Ta anomalies.The plagioclase amphibolites have positive whole-rockεNd(t)(+3.2 to+4.3)and zirconεHf(t)(+4.3 to+10.7)values,indicating that they were derived from an OIB-like asthenospheric mantle source.The granites belong to the reduced peralkaline A-type series and have negativeεNd(t)value of-6.0 andεHf(t)values of-5.8 to-13.8,indicating a derivation from the partial melting of ancient mafic lower crust.In combination with the~1.05-1.02 Ga bimodal igneous assemblage in the SW Yangtze Block,we propose that the Cuoke 1168-1162 Ma igneous rocks were likely formed in a continental rift basin and argue against the existance of Grenvillian Orogen in the SW Yangtze Block during the late Mesoproterozoic. 展开更多
关键词 Late Mesoproterozoic Zircon U-Pb geochronology Elemental and isotopic data Within-plate igneous rocks continental rift Yangtze Block
下载PDF
Dynamic Analysis on Rifting Stage of Pearl River Mouth Basin through Analogue Modeling 被引量:6
17
作者 孙珍 周蒂 +4 位作者 孙龙涛 陈长民 庞雄 姜建群 樊浩 《Journal of Earth Science》 SCIE CAS CSCD 2010年第4期439-454,共16页
The Pearl River Mouth basin (PRMB) is a marginal sedimentary basin of the South China Sea. It trends NE and is divided into three segments from west to east by two NW-trending faults. Changing dramatically in struct... The Pearl River Mouth basin (PRMB) is a marginal sedimentary basin of the South China Sea. It trends NE and is divided into three segments from west to east by two NW-trending faults. Changing dramatically in structures along and across strike, the PRMB is a good example to analyze main factors that might control the process of a continental rift basin's extension. Through five series of analogue experiments, we investigate the role of different factors, such as pre-existing discontinuities of crust, rheological profiles of lithosphere, kinematics of extension and presence of magmatic bodies and strong crustal portions (rigid massifs) on the development of basin's structures. After being compared with the architecture of the natural prototype, the results of the analogue models were compared with the architecture of the natural prototype and used to infer the role of the different factors controlling the formation and evolution of the PRMB. The main conclusions are as follows. (1) Affected by pre-Cenozoic structures, the PRMB was controlled by crosscut NE- and NW-trending initial faults, and the NW-trending Yitong'ansha (--~l~) fault may be a through-going fault along dip and offset the NE-trending rift and faults, while the Enpingdong (和统暗沙) fault might exist only in the middle and south. (2) The NW-trending faults may orient WNW to be sinistrally transtensional under SE to nearly NS extension. (3) The thickness ratio of brittle over ductile crust in Baiyun (白云) sag is lessthan normal, suggesting an initially hot and weak lithosphere. (4) The magma must have taken part in the rifting process from early stage, it may occur initially upon or slightly south of the divergent boundary in the middle segment. The flow of magma toward rift boundary faults caused extra vertical subsidence above the initial magma reservoir without creating a large extensional fault. (5) The rigid massif contributed to the strain partition along and across basin strike. 展开更多
关键词 Pearl River Mouth basin analogue modeling controlling factor of continental rift basin.
原文传递
A near-shore clastic-carbonate mixing mode in a continental rift basin(early Oligocene,eastern Shijiutuo Uplift,Bohai Bay Basin,China):sedimentology,reservoir characteristics and exploration practice 被引量:1
18
作者 Xiao-Feng Du Hao Liu +3 位作者 Xiao-Bo Huang Zhang-Qiang Song Wei Xu Can Zhang 《Journal of Palaeogeography》 SCIE CSCD 2020年第4期438-455,共18页
A comprehensive sedimentary and reservoir analysis was conducted based on seismic,well logging,core and relative test data,taking Members 1 and 2 of Shahejie Formation of the early Oligocene in the steep slope belt,ea... A comprehensive sedimentary and reservoir analysis was conducted based on seismic,well logging,core and relative test data,taking Members 1 and 2 of Shahejie Formation of the early Oligocene in the steep slope belt,eastern Shijiutuo Uplift(STU),Bohai Bay Basin(BBB)as a case.The study indicates that a near-shore mixed fan deposit formed in the study area and developed characteristics and pattern of a high-quality reservoir.The mixed clastic-carbonate rocks constitute Members 1 and 2 of Shahejie Formation which developed along the steep slope belt and is named as a near-shore mixed fan.The mixed fan of the study area is mainly composed of microfacies of proximal channel,mixed deposited channel,mixed clastic beach,mixed bioclastic(grain)beach,with vertical multi-stage superimposition feature,and basically a similar shape as modern near-shore fans.It constitutes a new depositional type developing in the steep slope belt of a characteristic and complex lacustrine rift basin in the study area.This mixed fan in the steep slope of eastern STU is controlled by comprehensive factors including tectonics,clastic material supply,climate,palaeogeomorphology and hydrodynamic conditions.The reservoir quality of Members 1 and 2 of Shahejie Formation of eastern STU is,however,actually controlled by the sedimentary environment and diagenesis processes.Coarse-grained mixed rocks of near-shore fans,rich in bioclastics,can form excellent reservoirs,characterized by resistance to compaction,easy to dissolution,little influenced by burial depth and high production of oil and gas,which enable them become key exploration targets of medium-deep strata of BBB.Analyses of high-quality reservoir,its controlling factors and the oil and gas exploration implications of the near-shore mixed fan developing in the study area give a deeper insight into discussions of the same type of mixed rocks of other lacustrine rift basins worldwide. 展开更多
关键词 early Oligocene eastern Shijiutuo Uplift Bohai Bay Basin continental rift basin mixed carbonate-siliciclastic fan high-quality reservoirs
原文传递
Tectonic evolution of convergent plate margins and its geological effects 被引量:14
19
作者 Yongfei ZHENG Yixiang CHEN +1 位作者 Renxu CHEN Liqun DAI 《Science China Earth Sciences》 SCIE EI CSCD 2022年第7期1247-1276,共30页
Oceanic lithosphere is generated at divergent plate boundaries and disappears at convergent plate boundaries.Seafloor spreading and plate subduction together constitute the physical coupling and mass conservation rela... Oceanic lithosphere is generated at divergent plate boundaries and disappears at convergent plate boundaries.Seafloor spreading and plate subduction together constitute the physical coupling and mass conservation relationships to the movement of lithospheres on Earth.Subduction zones are a key site for the transfer of both matter and energy at converging plate boundaries,and their study has been the hot spot and frontier of Earth system science since the development of plate tectonics theory.As far as the dynamic regime and geothermal gradient of convergent plate margins are concerned,they have different properties in different stages of the subduction zone evolution.In general,the early low-angle subduction leads to compressional tectonism dominated by low geothermal gradients at the plate interface,and the late high-angle subduction results in extensional tectonism dominated by high geothermal gradients at the plate interface and its hanging wall.Active rifts are produced along suture zones through not only slab rollback or slab breakoff in the terminal stage of oceanic subduction but also foundering and thinning of the lithosphere in the post-subduction stage.Due to the differences and changes in the geometric and thermobaric structures of convergent plate margins,a series of changes in the type of metamorphism and magmatism can occur in active and fossil subduction zones.Dehydration and melting of the subducting oceanic crust are prominent at subarc depths,giving rise to fluids that dissolve different concentrations of fluid-mobile incompatible elements.The subduction zone fluids at subarc depths would chemically react with the overlying mantle wedge peridotite,generating metasomatites as the mantle sources of mafic magmas in oceanic and continental arcs.However,these metasomatites did not partially melt immediately upon the fluid metasomatism to trigger arc magmatism,and they did not melt until they were heated by asthenospheric convection due to rollback of the subducting slab.Therefore,recognition of the changes in the dynamic regime and geothermal gradient of subduction zones in different stages of plate convergence not only provides insights into geodynamic mechanisms of the tectonic evolution from subduction zones to orogenic belts,but also places constraints on the formation and evolution of different types of metamorphic and magmatic rocks within the advanced framework of plate tectonics. 展开更多
关键词 Plate tectonics continental geology Convergent margins continental rifting Subduction zone Orogenic belt
原文传递
Tectonic evolution and geodynamics of the Neo-Tethys Ocean 被引量:18
20
作者 Rixiang ZHU Pan ZHAO Liang ZHAO 《Science China Earth Sciences》 SCIE EI CSCD 2022年第1期1-24,共24页
The Neo-Tethys Ocean was an eastward-gaping triangular oceanic embayment between Laurasia to the north and Gondwana to the south.The Neo-Tethys Ocean was initiated from the Early Permian with mircoblocks rifted from t... The Neo-Tethys Ocean was an eastward-gaping triangular oceanic embayment between Laurasia to the north and Gondwana to the south.The Neo-Tethys Ocean was initiated from the Early Permian with mircoblocks rifted from the northern margin of Gondwana.As the microblocks drifted northwards,the Neo-Tethys Ocean was expanded.Most of these microblocks collided with the Eurasia continent in the Late Triassic,leading to the final closure of the Paleo-Tethys Ocean,followed by oceanic subduction of the Neo-Tethys oceanic slab beneath the newly formed southern margin of the Eurasia continent.As the splitting of Gondwana continued,African-Arabian,Indian and Australian continents were separated from Gondwana and moved northwards at different rates.Collision of these blocks with the Eurasia continent occurred at different time during the Cenozoic,resulting in the closure of the Neo-Tethys Ocean and building of the most significant Alps-Zagros-Himalaya orogenic belt on Earth.The tectonic evolution of the Neo-Tethys Ocean shows different characteristics from west to east:Multi-oceanic basins expansion,bidirectional subduction and microblocks collision dominate in the Mediterranean region;northward oceanic subduction and diachronous continental collision along the Zagros suture occur in the Middle East;the Tibet and Southeast Asia are characterized by multi-block riftings from Gondwana and multi-stage collisions with the Eurasia continent.The negative buoyancy of subducting oceanic slabs can be considered as the main engine for northward drifting of Gondwana-derived blocks and subduction of the Neo-Tethys Ocean.Meanwhile,mantle convection and counterclockwise rotation of Gondwana-derived blocks and the Gondwana continent around an Euler pole in West Africa in non-free boundary conditions also controlled the evolution of the Neo-Tethys Ocean. 展开更多
关键词 Neo-Tethys tectonic domain Neo-Tethys Ocean continental rift and amalgamation Gondwana continent Nonfree boundary condition Euler pole GEODYNAMICS
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部