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Multiple Uplift and Exhumation of the Southeastern Tibetan Plateau:Evidence from Low-Temperature Thermochronology

Acta Geologica Sinica(English Edition) 2024年第3期98卷 569-584页

作者： WU Limin PENG Touping fan weiming ZHAO Guochun GAO Jianfeng DONG Xiaohan PENG Shili MIN Kang Tin Aung MYINT State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Chinese Academy of Sciences Center for Excellence in Deep Earth Science Guangzhou 510640China University of Chinese Academy of Sciences Beijing 100049China Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China Department of Earth Sciences The University of Hong KongHong Kong 999077China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) ZhuhaiGuangdong 519085China Department of Geology University of MandalayMandalay 05011Myanmar

Since the Cenozoic,the Tibetan Plateau has experienced large-scale uplift and outgrowth due to the India-Asia ***,the mechanism and timing of these tectonic processes still remain ***,using apatite fission track dating and inverse thermal modeling,we explore the mechanism of different phases of rapid cooling for different batholiths and intrusions in the southeastern Tibetan *** contrast to previous views,we find that the coeval granitic batholith exposed in the same tectonic zone experienced differential fast uplift in different sites,indicating that the present Tibetan Plateau was the result of differential uplift rather than the entire lithosphere uplift related to lithospheric collapse during Cenozoic *** addition,we also suggest that the 5-2 Ma mantle-related magmatism should be regarded as the critical trigger for the widely coeval cooling event in the southeastern Tibetan Plateau,because it led to the increase in atmospheric CO_(2)level and a hotter upper crust than before,which are efficient for suddenly fast rock weathering and ***,we propose that the current landform of the southeastern Tibetan Plateau was the combined influences of tectonic and climate.

关键词： apatite fission track rapid cooling differential uplift magmatism southeastern Tibetan Plateau

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Endoscopy-assisted lightweight diagnosis system based on transformers for colon polyp detection

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Optoelectronics Letters 2024年

作者： fan weiming YU Jiahui JU Zhaojie School of Automation and Electrical Engineering， Shenyang Ligong University Department of Biomedical Engineering， Zhejiang University School of computing， University of Portsmouth

The integration of endoscopy has significantly propelled the diagnosis and treatment of gastrointestinal diseases， with colonoscopy establishing itself as the primary method for early diagnosis and preventive care in colorectal cancer. Although deep learning holds promise in mitigating missed polyp rates， modern endoscopy examinations pose additional challenges， such as image blurring and atomizing. This study explores lightweight yet powerful attention mechanisms， introducing the Spatial-Channel Transformer—an innovative approach that leverages spatial channel relationships for attention weight calculation. The method utilizes rotation operations for inter-dimensional dependencies， followed by residual transformation， encoding inter-channel and spatial information with minimal computational overhead. Extensive experiments on the CVC-ClinicDB polyp detection dataset， addressing endoscopy pitfalls， underscore the superiority of our Spatial-Channel Transformer over other state-of-the-art methods. The proposed model maintains high performance， even in challenging scenarios.

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Robust facial expression recognition via lightweight reinforcement learning for rehabilitation robotics

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Optoelectronics Letters 2024年

作者： CHEN Yifan fan weiming GAO Hongwei YU Jiahui JU Zhaojie School of Computing， University of Portsmouth School of Automation and Electrical Engineering， Shenyang Ligong University Department of Biomedical Engineering Zhejiang Univeristy

The Facial Expression Recognition (FER) capability could endow machines with a more accurate evaluation of rehabilitation robots， making rehabilitation robots’ experience more harmonious and credible. How to obtain robust facial expression representation features has yet to be fully explored. Moreover， the convolutional networks often used in facial expression recognition usually have many parameters， which is not conducive to the online diagnosis of rehabilitation robots. Therefore， this paper proposes a Lightweight Reinforcement Network (LRN) and Auxiliary Label Distribution Learning (ALDL) based robust FER method. Our designed representation reinforcement network mainly comprises two modules， i.e.， the Representation Reinforcement (RR) module and the Auxiliary Label Space Construction (ALSC) module. RR module highlights key feature messaging nodes in feature maps， and ALSC allows multiple labels with different intensities to be linked to one expression. Therefore， LRN has a more robust feature extraction capability when model parameters are greatly reduced， and ALDL is proposed to contribute to the training effect of LRN in the condition of ambiguous training data. We tested our method on FER-Plus， and RAF-DB data sets， and the experiment demonstrates the feasibility of our method in practice during rehabilitation robots.

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滇西剑川始新世粗面岩及其包体成因:印度-欧亚大陆碰撞过程的约束和大地构造意义

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大地构造与成矿学 2024年第4期48卷 820-843页

作者：董晓涵彭头平范蔚茗刘兵兵彭世利武利民中国科学院广州地球化学研究所同位素地球化学国家重点实验室广东广州510640 中国科学院大学北京100049 中国科学院深地科学卓越创新中心广东广州510640 中国科学院青藏高原研究所北京100101

新生代以来,印度-欧亚大陆碰撞导致青藏高原发生大规模隆升和岩石圈挤出,这一过程引发了金沙江-哀牢山-红河构造带等深大断裂带的大规模剪切走滑,并沿该构造带发生强烈的碱性岩浆作用。这些始新世碱性岩记录了印度-欧亚大陆的早期碰撞过... 详细信息

新生代以来,印度-欧亚大陆碰撞导致青藏高原发生大规模隆升和岩石圈挤出,这一过程引发了金沙江-哀牢山-红河构造带等深大断裂带的大规模剪切走滑,并沿该构造带发生强烈的碱性岩浆作用。这些始新世碱性岩记录了印度-欧亚大陆的早期碰撞过程,因而可以作为研究青藏高原早期隆升和岩石圈挤出过程及其深部动力学机制的重要“探针”。本文针对剑川盆地甸南地区始新世粗面岩及其二长岩包体和辉长岩包体开展了系统的锆石U-Pb年代学、Lu-Hf同位素和全岩主-微量元素和Sr-Nd同位素组成研究。锆石U-Pb定年结果显示,剑川盆地甸南粗面岩形成时代为36Ma;其内部包含的两件二长岩包体的形成年龄分别为41.6±3.4 Ma和35.7±0.3 Ma,一件辉长岩包体的形成时代为35.8±0.2 Ma。地球化学研究结果显示,粗面岩与二长岩包体K_(2)O含量均较高,属于钾玄质系列岩石,且富集轻稀土元素(LREE)和大离子亲石元素(LILE),亏损高场强元素(HFSE)。结合锆石Hf同位素和全岩Sr-Nd同位素组成,表明甸南地区寄主粗面岩和二长岩包体来自相同的交代富集岩石圈地幔的部分熔融,并经历了不同程度的橄榄石和辉石分离结晶作用。包体研究显示,~41Ma二长岩包体为寄主粗面岩岩浆上升过程中捕获自早期围岩,而~36Ma二长岩包体为同源岩浆房内与围岩接触淬冷的早期结晶产物,它们被寄主粗面岩岩浆裹挟而存在其内部。堆晶辉长岩包体较寄主粗面岩和二长岩包体具明显低的K2O、稀土和微量元素含量,其全岩Nd同位素组成与剑川盆地二龙山橄榄玄武岩相似,但高于寄主粗面岩,表明其源自弱富集地幔的部分熔融,并在壳-幔过渡带堆晶形成。此外,~41 Ma碱性岩包体和碱性岩内46~38 Ma捕获锆石年龄,以及剑川盆地内近源沉积岩内碎屑锆石的同期年龄记录,均表明金沙江-哀牢山-红河碱性岩带的岩浆作用并非存在从高原内部向东南方向的滇西地区逐渐变年轻的趋势,而是印度-欧亚大陆碰撞过程中,岩石圈向东南向挤出导致兰坪-思茅地块和印支地块旋转挤出的响应。

关键词：青藏高原金沙江-哀牢山-红河构造带粗面岩包体岩石圈挤出

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K-Ar dating of late Mesozoic volcanism and geochemistry of volcanic gravels in the North Huaiyang Belt, Dabie orogen: Constraints on the stratigraphic framework and exhumation of the northern Dabie orthogneiss complex

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Chinese Science Bulletin 2002年第20期47卷 1688-1695页

作者： Yuejun Wang weiming fan Feng Guo Chinese Acad Sci Guangzhou Inst Geochem Guangzhou 510640 Peoples R China

Two eruption episodes are identified through systematic field investigations and K-Ar dating of the late Mesozoic volcanic rocks in the North Huaiyang belt (NHB), Dabie orogenic belt, of which the earlier volcanic suite termed Maotanchang Fm. (Fm.) occurring at Jinzhai, Xianhualing and Maotanchang, etc., was erupted from 149 Ma to 138 Ma. The other named Xiaotian Fm. mainly distributed at Xiaotian, Shucheng, etc., was formed between 132 Ma and 116 Ma. During the eruption gap of the two volcanic suites deposited a volcano-sedimentary conglomerate layer, which are composed of the multi-compositional gravels, including the North Dabie orthogneiss complex (NDOC), volcanic gravels, etc. These volcanic gravels in the conglomerate layer show identical geochemical and isotopic compositions (87Sr/86Sr(t) =0.7084-0.7092,εNd(t) =-21.8--24.4) to the Maotanchang Fm. volcanic rocks (87Sr/86Sr = 0.7086-0.7102,εNd = -19.2-24.4), but significantly distinct from those of Xiaotian Fm. (87Sr/86Sr = 0.7076-0.7084, εNd=

关键词： multi-gravel conglomerate layer K-Ar dating geo-chemical comparison late Mesozoic uplifting-erosion North Huai-yang belt.

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Dynamics of unstable continental subduction:Insights from numerical modeling

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Science China Earth Sciences 2017年第2期60卷 218-234页

作者： HUANGFU PengPeng WANG YueJun fan weiming LI ZhongHai ZHOU YongZhi School of Earth Science and Geological Engineering Sun Yat-sen University Key Laboratory of Computational Geodynamics College of Earth SciencesUniversity of Chinese Academy of Sciences CAS Center for Excellence in Tibetan Plateau Earth Sciences Key Laboratory of Continental Collision and Plateau UpliftInstitute of Tibetan Plateau ResearchChinese Academy of Sciences

Numerical experiments are used in this study to systematically investigate the effects of convergence rate,crustal rheological strength,and lithospheric thermal structure on the dynamics of continental *** study focuses on the types,conditions and processes of unstable continental *** results suggest that the development of unstable continental subduction can be promoted by conditions that tend to decrease rheological strength of the lithosphere,such as low crustal rheological strength,"hot"thermal structure of the lithosphere,or low convergence *** subduction mode can be further categorized into three types:(1)multi-stage slab breakoff,(2)continuously"flowing"of fluid-like slab into the upper mantle,and(3)large-scale detachment of the thickened orogenic *** three types of unstable continental subduction are respectively associated with(1)a low convergence rate,(2)"hot"thermal structure of the lithosphere with a high convergence rate,and(3)moderate-high crustal rheological strength with a low convergence *** is also revealed that the evolution of crustal melting is dominated by the deformation pattern of continental collision,which is mainly controlled by crustal rheological *** modelling results have important implications for understanding of continental subduction mode selection under specific geodynamic conditions.

关键词： Unstable continental subduction Stable continental subduction Slab breakoff Detachment Partial melting

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Effects of Crustal Eclogitization on Plate Subduction/Collision Dynamics: Implications for India-Asia Collision

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Journal of Earth Science 2016年第5期27卷 727-739页

作者： Pengpeng Huangfu Yuejun Wang Zhonghai Li weiming fan Yan Zhang State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Key Laboratory of Computational Geodynamics College of Earth Sciences University of Chinese Academy of Sciences School of Earth Science and Geological Engineering Sun Yat-Sen University CAS Center for Excellence in Tibetan Plateau Earth Sciences Key Laboratory of Continental Collision and Plateau UpliftInstitute of Tibetan Plateau Research Chinese Academy of Sciences

2D thermo-mechanical models are constructed to investigate the effects of oceanic and continental crustal eclogitization on plate dynamics at three successive stages of oceanic subduction, slab breakoff, and continental subduction. Crustal eclogitization directly increases the average slab density and accordingly the slab pull force, which makes the slab subduct deeply and steeply. Numerical results demonstrate that the duration time from initial continental collision to slab breakoff largely depends on the slab pull force. Specifically, eclogitization of subducted crust can greatly decrease the duration time, but increase the breakoff depth. The detachment of oceanic slab from the pro-continental lithosphere is accompanied with obvious exhumation of the subducted continental crust and a sharp uplift of the collision zone in response to the disappearance of downward drag force and the induced asthenospheric upwelling, especially under the condition of no or incomplete crustal eclogitization. During continental subduction, the slab dip angle is strongly correlated with eclogitization of subducted continental lower crust, which regulates the slab buoyancy nature. Our model results can provide several important implications for the Himalayan-Tibetan collision zone. For example, it is possible that the lateral variations in the degree of eclogitization of the subducted Indian crust might to some extent contribute to the lateral variations of subduction angle along the Himalayan orogenic belt. Moreover, the accumulation of highly radiogenic sediments and upper continental crustal materials at the active margin in combination with the strong shear heating due to continuous continental subduction together cause rising of isotherms in the accretionary wedge, which facilitate the development of crustal partial melting and metamorphism.

关键词： numerical modeling crustal eclogitization oceanic subduction slab breakoff continen-tal subduction Himalayan-Tibetan collision zone.

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Early Paleozoic subduction of the Paleo-Asian Ocean: Geochronological and geochemical evidence from the Dashizhai basalts, Inner Mongolia

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Science China Earth Sciences 2009年第7期52卷 940-951页

作者： GUO Feng fan weiming LI ChaoWen MIAO LaiCheng ZHAO Liang Key Laboratory of Marginal Sea Geology Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

Zircon U-Pb results of basalt from the Dashizhai Town in Inner Mongolia, NE China, shows that the basaltic lava was erupted at 439±3 Ma, much older than the "Permian basalts" as previously thought. These rocks show arc-type trace element patterns (i.e., Nb-Ta depletion and light REE and large ion lithophile element enrichment) and unradiogenic Sr and highly radiogenic Nd and Hf isotope compositions. They can be subdivided into two petrogenetic groups: Group 1 basalts have relatively high TiO2, MgO and compatible elements and low Sr and Th, characterized by mid-oceanic ridge basalt (MORB)-type Sr-Nd-Hf isotope compositions (87Sr/86Sr(i)=0.7028―0.7032, εNd(t)=+9.8-+11.2, εHf(t)=+16.1- +18.4). Group 2 has lower TiO2, MgO and compatible elements and higher Sr and Th, and relatively evolved Sr-Nd-Hf isotope compositions (87Sr/86Sr(i)=0.7037-0.7038, εNd(t)=+5.7-+7.3, εHf(t)=+12.6- +13.0). Both groups were interpreted as melts derived from a metasomatized mantle wedge formed during the subduction of Paleo-Asian Ocean. The mantle source for Group 1 was probably a highly isotopically depleted oceanic mantle modified by predominant slab fluids; whereas subducted sediments had an important contribution to the melting source for Group 2. The petrogenesis of the Dashizhai basalts provides clear evidence for early Paleozoic subduction of the Paleo-Asian Ocean, and the highly radiogenic Nd and Hf compositions in these rocks suggest that these lavas and their possible intrusive counterparts were one of the important components for Phanerozoic crustal growth. Our and previous studies on the "Dashizhai Formation" volcanic rocks yield an unrealistic eruption range of 440-270 Ma for different rock types, we thus advise to disassemble the previously defined "Dashizhai Formation" into multiple lithologic units and to reinterpret the spatial and temporal distributions of different volcano-sedimentary associations.

关键词： subduction Paleo-Asian Ocean Dashizhai basalts early Paleozoic Inner Mongolia

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Multitaper spectral method to estimate the elastic thickness of South China: Implications for intracontinental deformation

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Geoscience Frontiers 2014年第2期5卷 193-203页

作者： Yangfan Deng Zhongjie Zhang weiming fan Marta Pérez-Gussinyé State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Guangzhou Institute of Geochemistry Chinese Academy of Science Department of Earth Sciences Royal Holloway University of London

The effective elastic thickness （Te） represents the thickness of the elastic layer or the flexural rigidity of the lithosphere, the equivalent of which can be calculated from the spectral analysis of gravity and topographic data. Studies of Te have profound influence on intracontinental deformation, and coupling of the tectonic blocks. In this paper, we use the multitaper spectral estimation method to calculate the coherence between Bouguer gravity and topography data, and to obtain the Te map of South China. Through the process of correction, we discuss the relationships of Te versus heat flow, and Te versus seismicity. The results show that Te distribution of South China is affected by three factors：the original age, which controls the basic feature;the Mesozoic evolution, which affects the Te distribution;and the neotectonic movement, which shaped the final distribution. The crust age has a positive correlation with the first-order Te distribution;thus the Yangtze Craton has a relatively higher Te （about 50 km） whereas the Te in Cathaysia block is only 10e20 km. By analysis and comparison among the tectonic models of South China, the Te distribution can be well explained using the flat-subduction model. As is typical with neotectonics, the region with a higher heat flow is related with a lower Te. The seismicity does not have a clear relationship with Te, but the strong seismicity could cause a low Te. Seismogenic layer （Ts） has a similar trend as Te in the craton, whereas in other areas the relationship is complex.

关键词： South China Effective elastic thickness Spectrum estimation Heat flow Seismicity

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Platinum-group element geochemistry of Cenozoic basalts from the North China Craton: Implications for mantle heterogeneity

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Science China Earth Sciences 2015年第6期58卷 881-895页

作者： ZHANG WenHui ZHANG HongFu SUN YaLi fan weiming HAN BaoFu TANG YanJie School of Zijin Mining Fuzhou University State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Guangzhou Institute of Geochemistry Chinese Academy of Sciences Department of Earth Sciences Peking University

Forty-two Cenozoic （mostly Miocene） basalt samples from Jining, Chifeng, fansi, Xiyang, and Zuoquan areas of the North China Craton （the NCC basalts hereafter） were analyzed for platinum-group elements （PGE, including Os, It, Ru, Rh, Pt, and Pd）. Most of them are alkaline basalts and tholeiites and all of them display little crustal contamination. The total PGE contents of the NCC basalts vary from 0.1 to 0.9 ppb, much lower than those of the primitive mantle values of 23.5 ppb. Primitive man- tie-normalized PGE patterns of these basalts define positive slopes and Pd/Ir ratios vary from 1.2 to 25. In terms of both PGE contents and Pd/Ir ratios, they are quite similar to the mid-ocean ridge basalts. There are no obvious negative correlations be- tween PGE vs. MgO, Ni, and Cu in the NCC basalts, indicating that fractional crystallization of olivine, pyroxene, and/or sul- fides during magmatic process cannot be the controlling factor for the observed PGE variation. The observed Pd/Ir variations of the NCC basalts require involvement of non-chondritic heterogeneous mantle sources. Based on Sr-Nd-Pb-Hf isotopic sys- tematics and incompatible-element signatures, a mixing of partial melts from both asthenospheric peridotites and enclosed mantle eclogites at the top of asthenosphere was proposed for the origin of these NCC basalts. The lenses of eclogites are de- rived from upwelling of recycled continental crust during the westward subduction of the Pacific plate from the -600 km dis- continuity zone. The PGE geochemistry of these basalts provides independent evidence to support this conclusion and the ob- served Pd/Ir variations may reflect variations in proportions of tapped peridotitic and eclogitic melts.

关键词： Continental basalts platinum group elements geochemistry North China Craton

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