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The transport of water in subduction zones

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science china {2. {3. 2016年第4期59卷 651-682页

作者： zheng yongfei CHEN RenXu XU zheng ZHANG ShaoBing school of earth and {2. {3. University of Science and Technology of China

The transport of water from subducting crust into the mantle is mainly dictated by the stability of hydrous minerals in subduction zones. The thermal structure of subduction zones is a key to dehydration of the subducting crust at different depths. Oceanic subduction zones show a large variation in the geotherm, but seismicity and arc volcanism are only prominent in cold subduction zones where geothermal gradients are low. In contrast, continental subduction zones have low geothermal gradients, resulting in metamorphism in cold subduction zones and the absence of arc volcanism during subduction. In very cold subduction zone where the geothermal gradient is very low(?5?C/km), lawsonite may carry water into great depths of ?3.0 km. In the hot subduction zone where the geothermal gradient is high(>2.?C/km), the subducting crust dehydrates significantly at shallow depths and may partially melt at depths of <80 km to form felsic melts, into which water is highly dissolved. In this case, only a minor amount of water can be transported into great depths. A number of intermediate modes are present between these two end-member dehydration modes, making subduction-zone dehydration various. Low-T/low-P hydrous minerals are not stable in warm subduction zones with increasing subduction depths and thus break down at forearc depths of ?60–80 km to release large amounts of water. In contrast, the low-T/low-P hydrous minerals are replaced by low-T/high-P hydrous minerals in cold subduction zones with increasing subduction depths, allowing the water to be transported to subarc depths of 80–160 km. In either case, dehydration reactions not only trigger seismicity in the subducting crust but also cause hydration of the mantle wedge. Nevertheless, there are still minor amounts of water to be transported by ultrahigh-pressure hydrous minerals and nominally anhydrous minerals into the deeper mantle. The mantle wedge overlying the subducting slab does not partially melt upon water influx

关键词： Subduction zones Oceanic crust Mantle wedge Thermal structure Hydrous minerals Water transport Arc magmatism

Mesozoic mafic magmatism in North china:Implications for thinning and destruction of cratonic lithosphere

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science china {2. {3. 2018年第4期61卷 353-385页

作者： yongfei zheng zheng XU Zifu ZHAO Liqun DAI CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space ScienceUniversity of Science and Technology of China

The North china Craton(NCC) has been thinned from >2.0 km to <100 km in its eastern part. The ancient subcontinental lithospheric mantle(SCLM) has been replaced by the juvenile SCLM in the Meoszoic. During this period... 详细信息

The North china Craton(NCC) has been thinned from >2.0 km to china, it has been hotly debated about the mechanism of cartonic *** study attempts to provide a resolution to current debates in the view of Mesozoic mafic magmatism in North china. We made a compilation of geochemical data available for Mesozoic mafic igneous rocks in the NCC. The results indicate that these mafic igneous rocks can be categorized into two series,manifesting a dramatic change in the nature of mantle sources at ~12. Ma. Mafic igneous rocks emplaced at this age start to show both oceanic island basalts(OIB)-like trace element distribution patterns and depleted to weakly enriched Sr-Nd isotope compositions. In contrast,mafic igneous rocks emplaced before and after this age exhibit both island arc basalts(IAB)-like trace element distribution patterrs and enriched Sr-Nd isotope *** difference indicates a geochemical mutation in the SCLM of North china at^12. Ma. Although mafic magmatism also took place in the Late Triassic, it was related to exhumation of the deeply subducted South china continental crust because the subduction of Paleo-Pacific slab was not operated at that time. Paleo-Pacific slab started to subduct beneath the eastern margin of Eruasian continent since the Jurrasic. The subducting slab and its overlying SCLM wedge were coupled in the Jurassic, and slab dehydration resulted in hydration and weakening of the cratonic mantle. The mantle sources of ancient IAB-like mafic igneous rocks are a kind of ultramafic metasomatites that were generated by reaction of the cratonic mantle wedge peridotite notonly with aqueous solutions

关键词： Cratonic destruction Mafic magmas IAB-like series OIB-like series Lithospheric thinning Slab subduction

Formation and evolution of Precambrian continental crust in South china

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Chinese science Bulletin 2007年第1期52卷 1-12页

作者： zheng yongfei ZHANG ShaoBing Key Laboratory of Crust-Mantle Materials and Environments Chinese Academy of Sciences School of Earth and Space SciencesUniversity of Science and Technology of China Hefei 230026 China

有～ 3..8 Ga 和 Hf 模型的 U-Pb 年龄的锆石的出现在华南～ 4 .0 Ga 变老在华南建议地府的外壳的残余的存在。而且，有象 4.1 Ga 一样旧的 U-Pb 年龄的由岩屑形成的锆石在西藏被发现了。这是到目前为止在中国报导的最旧的锆石。这些结... 详细信息

有～ 3..8 Ga 和 Hf 模型的 U-Pb 年龄的锆石的出现在华南～ 4 .0 Ga 变老在华南建议地府的外壳的残余的存在。而且，有象 4.1 Ga 一样旧的 U-Pb 年龄的由岩屑形成的锆石在西藏被发现了。这是到目前为止在中国报导的最旧的锆石。这些结果暗示那个大陆人外壳比以前想在是更普遍的晚地府，但是它的多数高效地被重做进太古代的大陆人外壳。根据可得到的锆石 U-Pb 年龄和 Hf 同位素数据，看来，在华南的大陆人外壳的生长后来开始了早太古代，但是著名计算机生产厂商通过重做的有能力的 cratonic 块没发生直到 Paleoproterozoic。自从 Eoarchean，因此，板 tectonics 的某形式的操作可以发生在中国大陆。华南 craton 的起始的破坏被集中的 magmatic 活动在 Neoproterozoic 期间与超级大陆 Rodinia 的集会和决裂联合引起。然而，大多数太古代并且在华南的 Paleoproterozoic 外壳的材料不作为表面岩石发生，但是作为分散的外壳的残余存在。不过， Neoproterozoic magmatism 的出现仍然是签名把华南与诺思中国区分开来。

关键词：前寒武纪大陆外壳中国

2. years of continental deep subduction

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Chinese science Bulletin 2009年第22期54卷 4266-4270页

作者： zheng yongfei CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space Science University of Science and Technology of China Hefei 230026 China

This year marks the 2.th anniversary of the discovery of coesite in metamorphic rocks of supracrustal origin. This initiated a revolution of the plate tectonics theory due to intensive studies of ultrahigh pres-sure m... 详细信息

关键词：大陆深俯冲超高压变质作用板块构造理论柯石英变质岩原产地史密斯科学家

Metamorphic evolution of the East Tethys tectonic domain and its tectonic implications

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science china {2. {3. 2023年第12期66卷 2686-2711页

作者： Qiangqiang ZHANG Xiaoying GAO Renxu CHEN yongfei zheng school of earth and {2. {3. Universiy of Science and Technology of ChinaHefei 230026China Key Laboraiory of Crust-Mantle Materials and Environments Chinese Academy of SciencesHefei 230026China Center of Excellence for Comparative Planetology Chinese Academy of sciences Hefei 230026China

The china Central Orogenic System(CCOS),extending in an east-west direction in the middle part of china,is composed of the Early Paleozoic Altyn-North Qilian-North Qaidam-East Kunlun-North Qinling-North Tongbai orogens in the west and the Late Paleozoic to Early Mesozoic South Tongbai-Hong'an-Dabie-Sulu orogens in the *** were produced by oceanic subduction and continental subduction/collision during the closure of the Proto-Tethys and the Paleo-Tethys oceans,*** types of metamorphic rocks with various ages are extensively exposed in these orogens,and they were produced at different geothermal gradients in different stages during the tectonic evolution of convergent continental margins,making them ideal targets to reconstruct the spatiotemporal evolution of the Eastern Tethys tectonic *** this article,an integrated study of metamorphic temperature(T)-pressure(P)-time(t)records is presented for metamorphic rocks along the CCOS,aiming to ascertain the change of metamorphic T/P ratios in both time and {2.,and then shed light on the tectonic evolution of the East Tethys tectonic domain in association with the thermal state change of convergent continental *** results indicate that despite the difference in metamorphic ages,metamorphic rocks in different orogens show a common trend with clockwise P-T-t *** respect to plate convergence for subduction and collision,regional metamorphism is categorized into three stages:(1)an early convergent stage,corresponding to low T/P Alpine-type blueschist-to eclogite-facies high-P to ultrahigh-P metamorphism;(2.a later convergent stage,corresponding to the medium T/P Barrovian-type medium-P amphibolite to high-P granulite-facies metamorphism;and(3.a post-convergent stage,corresponding to the high T/P Buchan-type lowP amphibolite to MP granulite-facies ***,a few metamorphic rocks only record a two-sage metamorphic evolution,with an early Barrovian-type high-P granuli

关键词： Tethys tectonics Oceanic closure Crustal metamorphism Geothermal gradient Intracontinental rifting

Tectonic evolution of convergent plate margins and its geological effects

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science china {2. {3. 2022年第7期65卷 1247-1276页

作者： yongfei zheng Yixiang CHEN Renxu CHEN Liqun DAI CAS Key Laboratory of Crust and Mantle Materials and Environments School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China

Oceanic lithosphere is generated at divergent plate boundaries and disappears at convergent plate *** spreading and plate subduction together constitute the physical coupling and mass conservation relationships to the movement of lithospheres on *** 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 *** 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 *** 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 *** 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 *** 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 *** and melting of the subducting oceanic crust are prominent at subarc depths,giving rise to fluids that dissolve different concentrations of fluid-mobile incompatible *** 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 ***,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 th

关键词： Plate tectonics Continental geology Convergent margins Continental rifting Subduction zone Orogenic belt

Advances in Deep-Learning-based Precipitation Nowcasting Techniques

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Journal of Tropical Meteorology 2024年第3期30卷 337-350页

作者： zheng Qun LIU Qi LAO Ping LU Zhen-ci school of earth and {2. {3./CMA-USTC Laboratory of Fengyun Remote Sensing University of Science and Technology of ChinaHefei 230026 China

Precipitation nowcasting,as a crucial component of weather forecasting,focuses on predicting very short-range precipitation,typically within six *** approach relies heavily on real-time observations rather than numerical weather *** core concept involves the spatio-temporal extrapolation of current precipitation fields derived from ground radar echoes and/or satellite images,which was generally actualized by employing computer image or vision ***,with stirring breakthroughs in artificial intelligence(AI)techniques,deep learning(DL)methods have been used as the basis for developing novel approaches to precipitation *** progress has been obtained in recent years,manifesting the strong potential of DL-based nowcasting models for their advantages in both prediction accuracy and computational *** paper provides an overview of these precipitation nowcasting approaches,from which two stages along the advancing in this field *** models that were established on an elementary neural network dominated in the first stage,while large meteorological models that were based on complex network architectures prevailed in the *** particular,the nowcasting accuracy of such data-driven models has been greatly increased by imposing suitable physical *** integration of AI models and physical models seems to be a promising way to improve precipitation nowcasting techniques further.

关键词： precipitation nowcasting deep learning neural network classic model large model

Growth and reworking of cratonic lithosphere

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Chinese science Bulletin 2009年第19期54卷 3347-3353页

作者： zheng yongfei WU FuYuan CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029. China

To study the thinning of cratonic lithosphere in North china has been the hot subject of basic research in the fields of solid earth {2. in china. This paper presents an overview on the formation and evolution of continental crust, and outlines the mechanisms of forming the lithospheric mantle. It is suggested that the thinning of cratonic lithosphere principally proceeds in two ways, one by subduc- tion erosion (e.g., North china), and the other by a combination of subduction erosion and underplating degistion (e.g., Yangtze).

关键词：岩石圈研究调查地球科学

Partial melting of carbonated mantle: element and isotope evidence from Cenozoic continental basalt in east-central china

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Partial melting of carbonated mantle: element and isotope ev...