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Geochemistry of island arc assemblage in the Eastern Desert of Egypt and the role of Pan-African magmatism in crustal growth of the Arabian–Nubian Shield:A review

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Acta Geochimica 2024年第3期43卷 588-622页

作者： Abdel-Aal MAbdel-Karim Mohamed MHamdy Adel A.Surour Geology department Faculty of ScienceZagazig UniversityZagazig 44519Egypt Geology department Faculty of ScienceTanta UniversityTanta 31527Egypt department of geological sciences Faculty of ScienceNew Galala City 43511Egypt Geology department Faculty of ScienceCairo UniversityGiza 12613Egypt

Neoproterozoic island arc assemblage of the Arabian–Nubian Shield(ANS)in the Eastern Desert(ED)of Egypt comprises juvenile suites of metavolcanics(MV),large amounts of meta-sedimentary rocks(MS),and voluminous metagabbros-diorites(MGD)and syn-tectonic intrusions of older granitoids(OG).We report here the updates of these four rock units in terms of classification,distribution,chemical characteristics,geodynamic evolution,metamorphism,and ages.In addition,we discuss these integrated data to elucidate a reasonable and reliable model for crustal evolution in the ANS.The main features of these rock units indicate their relation to each other and the geodynamic environment dominated by early immature oceanic island arcs to primitive continental arcs.Integrated information of the island arc metavolcanic and plutonic rocks(gabbros,diorites,tonalites,and granodiorites)furnish evidence of the genetic relationships.These include proximity and a coeval nature in the field;all protolith magmas are subalkaline in nature following calc-alkaline series with minor tholeiitic affinities;common geochemical signature of the arc rocks and subduction-related magmatism;their similar enrichment in LREEs;and similar major element compositions with mafic melts derived from metasomatized mantle wedge.The volcano-sedimentary and the OG rocks underwent multiphase deformation events whereas the MGD complexes deformed slightly.Based on the magmatic,sedimentological,and metamorphic evolutions constrained by geochronological data as well as the progressive evolutionary trend from extensional to compressional regimes,a possible gradual decrease in the subducted slab dip angle is the most infl uential in any geodynamic model for arc assemblage in the ED of Egypt.

关键词： Island arc assemblage Magmatism Crustal growth Neoproterozoic Arabian–Nubian Shield Eastern Desert Egypt

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Petrogenesis and tectonic implications of the Silurian adakitic granitoids in the eastern segment of the Qilian Orogenic Belt,Northwest China

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Acta Geochimica 2024年第1期43卷 72-86页

作者： Jiao-Long Zhao Xiao-Jun Huang Pei-Qing Hu Zhen-Xi Yang Ying Fan Er-Teng Wang Fu-Bo Yang Jing-Yu Zhang School of Earth sciences Key Laboratory of Mineral Resources in Western China(Gansu Province)Lanzhou UniversityLanzhou 730000China Nuclear Industry 247 Brigade Tianjin North China Geological Survey BureauTianjin 301800China Fourth Institute of geological and Mineral Exploration of Gansu Provincial Bureau of Geology and Mineral Resources Jiuquan 735000China

Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon U–Pb age, and systematic whole-rock geochemical data for the Haoquangou and Liujiaxia granitoids within the North Qilian orogenic belt and the Qilian Block, respectively, to constrain their petrogenesis, and the Silurian tectonic evolution of the Qilian orogenic belt. Zircon U–Pb ages indicate that the Haoquangou and Liujiaxia intrusions were emplaced at423 ± 3 Ma and 432 ± 4 Ma, respectively. The Haoquangou granodiorites are calc-alkaline, while the Liujiaxia granites belong to the high-K calc-alkaline series.Both are peraluminous in composition and have relatively depleted Nd isotopic [ε_(Nd)(t) =(-3.9 – + 0.6)] characteristics compared with regional basement rocks, implying their derivation from a juvenile lower crust. They show adakitic geochemical characteristics and were generated by partial melting of thickened lower continental crust. Postcollisional extensional regime related to lithospheric delamination was the most likely geodynamic mechanism for the generation of the Haoquangou granodiorite, while the Liujiaxia granites were generated in a compressive setting during continental collision between the Qaidam and Qilian blocks.

关键词： Silurian adakitic granitoids Petrogenesis Tectonic setting Qilian Orogenic Belt

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Geochronology and Geochemistry of Ore-related Granitoids in the Giant Gariatong Rb Deposit,Tibet and Implications for Rb Metallogeny in China

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 83-103页

作者： LIN Bin TANG Juxing TANG Pan SUN Yan QI Jing MSANTOSH XIE Jinling DENG Shilin LI Faqiao XIE Fuwei ZHOU Aorigele MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China SinoProbe Laboratory Chinese Academy of Geological SciencesBeijing 100094China The Key Laboratory of the Ministry of Education on Solid Waste Treatment and Recycling School of Environment and ResourceSouthwest University of Science and TechnologyMianyangSichuan 621010China School of Earth sciences and Resources China University of Geosciences(Beijing)Beijing 100083China department of Earth sciences University of AdelaideAdelaide SA-5005Australia Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 610031China Regional geological Survey Team of the Tibetan Bureau of Geology and Mineral Exploration and Development Lhasa 851400China College of Earth Science and Key Laboratory of Tectonic Controlled Mineralization and Oil Reservoirs Chengdu University of TechnologyChengdu 610059China

Rubidium(Rb)deposits mostly occur in the South China and Central Asia orogenic belts and are often closely associated with highly differentiated granites.This study investigates a newly-discovered giant Rb deposit at Gariatong in the Central Lhasa terrane in Tibet.Detailed field studies and logging data revealed that the Rb mineralization mainly occurs in monzogranite and is related to greisenization.LA-ICP-MS U-Pb dating of zircon yielded ages of 19.1±0.2 Ma and 19.0±0.2 Ma for greisenized monzogranite and fresh monzogranite,respectively.The monzogranites are characterized as strongly peraluminous,with high contents of SiO2,Al2O3,K2O and Na2O as well as a high differentiation index.They are enriched in light rare earth and large ion lithophile elements with significant negative Eu anomalies and depleted high fieldstrength elements.Petrological and geochemical features of these ore-related monzogranites suggest that they are highly fractionated S-type granites,derived from remelting of crustal materials in a post-collisional setting.The geochemistry of zircon and apatite points to a low oxygen fugacity of the ore-related monzogranite during the magma’s evolution.The discovery of the Gariatong Rb deposit suggests that the Central Lhasa terrane may be an important region for rare metal mineralization.

关键词： LA-ICP-MS U-Pb dating geochemistry Rb metallogeny Gariatong Tibet

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The Weixi High-silica Granitoids in the Central Sanjiang Orogenic Belt,Southwest China:Implications for Growth of the Continental Crust

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 641-656页

作者： WANG Qiuyu CHEN Shouming ZHANG Hongrui LI Saisai SinoProbe Laboratory Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China Guangxi Key Laboratory of Hidden Metallic Ore Deposit Exploration GuilinGuangxi 541004China

High-silica granitoids record the formation and evolution of the continental crust.A new intrusive complex has been recognized among silicic volcanic rocks of the Weixi arc,Southwest China.The intrusions consist of granites,granitic porphyries,and granodiorites.Zircon U-Pb age data indicate that the Weixi granitoids formed at 248-240 Ma and were coeval with silicic volcanic rocks of the Weixi arc.The Weixi granitoids are enriched in Rb,Th,and U,depleted in Ba,Sr,Nb,Ta,and Ti,and have high light/heavy rare earth element ratios and slightly negative Eu anomalies.The Weixi granitoids have negative ε_(Nd)(t)values(-9.8 to-7.8)and negative zircon ε_(Hf)(t)values(-12.02 to-5.11).The geochemical and isotopic features suggest the Weixi granitoids were derived by partial melting of ancient crustal material.The Weixi granitoids and silicic volcanic rocks were derived from the same magma by crystal accumulation and melt extraction,respectively,and they record the formation of a continental arc in the central Sanjiang orogenic belt.

关键词： granitoids geochemistry crystal accumulation continental crust Sanjiang orogen

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A comprehensive review on pharmacognosy, phytochemistry and pharmacological activities of 8 potent Prunus species of southeast Asia

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Journal of Traditional Chinese Medicine 2024年第3期44卷 620-628页

作者： Shikha Agrawal Adarsh Kumar Ankit Kumar Singh Harshwardhan Singh Suresh Thareja Pradeep Kumar department of Pharmaceutical sciences and Natural Products Central University of Punjab

Genus Prunus comprising around 430 species is a vast important genus of family Rosaceae, subfamily amygdalaoidae. Among all 430 species, around 19 important species are commonly found in Indian subcontinent due to their broad nutritional and economic importance. Some most common species of genus Prunus are Prunus amygdalus, Prunus persica, Prunus armeniaca, Prunus avium, Prunus cerasus, Prunus cerasoides, Prunus domestica, Prunus mahaleb, etc. A newly introduced species of Prunus i.e Prunus sunhangii is recently discovered which is morphologically very similar to Prunus cerasoides. Plants of Prunus species are short to medium-sized deciduous trees mainly found in the northern hemisphere. In India and its subcontinent,it extends from the Himalayas to Sikkim, Meghalaya,Bhutan, Myanmar etc. Different Prunus species have been extensively studied for their morphological,microscopic, pharmacological and phytoconstituents characteristics. Total phenolic content of Prunus species explains the presence of phenols in high quantity and pharmacological activity due to phenols. Phytochemical screening of species of genus Prunus shows the presence of wide phytoconstituents which contributes in their pharmacological significance and reveals the therapeutic potential and traditional medicinal significance of this genus. Genus Prunus showed a potent antioxidant activity analyzed by 1,1-diphenyl-2-picryl-hydrazyl radical assay. Plant species belonging to the genus Prunus is widely used traditionally for the treatment of various disorders. Some specific Prunus species possess potent anticancer, anti-inflammatory,hypoglycemic etc. activity which makes the genus more interesting for further research and findings. This review is an attempt to summarize the comprehensive study of Prunus species from its distribution, morphological characters to phytoconstituents, and pharmacological activity.

关键词： Prunus Rosaceae antineoplastic agents distribution hypoglycemic agents phytochemistry review

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Dynamic response mechanism and precursor characteristics of gneiss rockburst under different initial burial depths

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Journal of Mountain Science 2024年第3期21卷 1004-1018页

作者： LIU Dongqiao SUN Jie MENG Wen HE Manchao ZHANG Chongyuan LI Ran CAO Binghao State Key Laboratory for Tunnel Engineering China University of Mining and TechnologyBeijing 100083China Key Laboratory of Active Tectonics and geological Safety Ministry of Natural ResourcesInstitute of GeomechanicsChinese Academy of Geological SciencesBeijing 100081China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing 100083China

To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system and acoustic emission(AE)monitoring system were used to monitor the entire rockburst process in real time.The experimental results show that when the initial burial depth increases from 928 m to 1320 m,the proportion of large fracture scale in rockburst increases by 154.54%,and the AE energy increases by 565.63%,reflecting that the degree and severity of rockburst increase with the increase of burial depth.And then,two mechanisms are proposed to explain this effect,including(i)the increase of initial geostress improves the energy storage capacity of gneiss,and then,the excess energy which can be converted into kinetic energy of debris ejection increases,consequently,a more pronounced violent ejection phenomenon is observed at rockburst;(ii)the increase of initial geostress causes more sufficient plate cracks of gneiss after unloading ofσh,which provides a basis for more severe ejection of rockburst.What’s more,a precursor with clear physical meaning for rockburst is proposed under the framework of dynamic response process of crack evolution.Finally,potential value in long term rockburst warning of the precursor obtained in this study is shown via the comparison of conventional precursor.

关键词： Traffic Engineering Gneiss Rockburst Crack propagation Excess energy Precursor characteristic

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Tocotrienol isoforms:The molecular mechanisms underlying their effects in cancer therapy and their implementation in clinical trials

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Journal of Integrative Medicine 2024年第1期22卷 1-11页

作者： Maria Younes Ghady Loubnane Christopher Sleiman Sandra Rizk department of Natural sciences Lebanese American UniversityByblosLebanon

Tocotrienols are found in a variety of natural sources,like rice bran,annatto seeds and palm oil,and have been shown to have several health-promoting properties,particularly against chronic diseases such as cancer.The incidence of cancer is rapidly increasing around the world,not only a result of continued aging and population growth,but also due to the adoption of aspects of the Western lifestyle,such as high-fat diets and low-physical activity.The literature provides strong evidence that tocotrienols are able to inhibit the growth of various cancers,including breast,lung,ovarian,prostate,liver,brain,colon,myeloma and pancreatic cancers.These findings,along with the reported safety profile of tocotrienols in healthy human volunteers,encourage further research into these compounds’potential use in cancer prevention and treatment.The current review provided detailed information about the molecular mechanisms of action of different tocotrienol isoforms in various cancer models and evaluated the potential therapeutic effects of different vitamin E analogues on important cancer hallmarks,such as cellular proliferation,apoptosis,angiogenesis and metastasis.MEDLINE/PubMed and Scopus databases were used to identify recently published articles that investigated the anticancer effects of vitamin E derivatives in various types of cancer in vitro and in vivo along with clinical evidence of adjuvant chemopreventive benefits.Following an overview of pre-clinical studies,we describe several completed and ongoing clinical trials that are paving the way for the successful implementation of tocotrienols in cancer chemotherapy.

关键词： Vitamin E Tocotrienols Cancer Molecular mechanism Clinical trials

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Experimental study on the effect of unloading rate on gneiss rockburst

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2064-2076页

作者： Dongqiao Liu Jie Sun Ran Li Manchao He Binghao Cao Chongyuan Zhang Wen Meng State Key Laboratory for Tunnel Engineering China University of Mining and TechnologyBeijing100083China Key Laboratory of Active Tectonics and geological Safety Ministry of Natural ResourcesInstitute of GeomechanicsChinese Academy of Geological SciencesBeijing100081China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China

Rockburst are often encountered in tunnel construction due to the complex geological conditions.To study the influence of unloading rate on rockburst,gneiss rockburst experiments were conducted under three groups of unloading rates.A high-speed photography system and acoustic emission(AE)system were used to monitor the entire process of rockburst process in real-time.The results show that the intensity of gneiss rockburst decreases with decrease of unloading rate,which is manifested as the reduction of AE energy and fragments ejection velocity.The mechanisms are proposed to explain this effect:(i)The reduction of unloading rate changes the crack propagation mechanism in the process of rockburst.This makes the rockbursts change from the tensile failure mechanism at high unloading rate to the tension-shear mixed failure mechanism at low unloading rate,and more energy released in the form of shear crack propagation.Then,less strain energy is converted into kinetic energy of fragments ejection.(ii)Less plate cracking degree of gneiss has taken shape due to decrease of unloading rate,resulting in the destruction of rockburst incubation process.The enlightenments of reducing the unloading rate for the project are also described quantitatively.The rockburst magnitude is reduced from the medium magnitude at the unloading rate of 0.1 MPa/s to the slight magnitude at the unloading rate of 0.025 MPa/s,which was judged by the ejection velocity.

关键词： Rockburst Unloading rate Crack propagation Influence mechanisms

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Ordovician integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

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Science China Earth sciences 2024年第4期67卷 971-1004页

作者： Xiang FANG Yong Yi ZHEN Guangxu WANG Xin WEI Zhongyang CHEN Yan LIANG Xuejin WU Wenjie LI Chao LI Renbin ZHAN Yuandong ZHANG State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China geological Survey of New South Wales W.B.Clarke Geoscience CentreNSW 2753Australia University of Chinese Academy of sciences Beijing 100049China

The Ordovician rocks on the Qinghai-Tibetan Plateau represent the oldest non-metamorphic strata,and are critical to understanding the history of regional geology and biotic evolution of the entire plateau.Strata of Floian,Darriwilian,Sandbian,Katian and Hirnantian are represented in the plateau with a hiatus of variable duration occurring underneath the basal Ordovician across the area.Five stratigraphical regions,including the Himalaya,Gangdise-Zayu,Qiangtang-Qamdo,Songpan-Garze,and Karakoram-Kunlun-Altun,are differentiated for the Ordovician strata,which are correlated with their equivalents in the Sibumasu,Indochina,Qaidam-Qilian,Tarim-Tianshan,and the Yangtze(western margin)stratigraphical regions.On the QinghaiTibetan Plateau,graptolites,conodonts,and cephalopods are the most common and useful fossils for the Ordovician biostratigraphy.The Ordovician biotas of the Qinghai-Tibetan Plateau bear some distinguishable palaeobiogeographical signatures,among which the cephalopods are characterized by the flourishing actinocerids of North China affinity in the Early-Middle Ordovician,and by the thriving lituitids and orthocerids of South China affinity in the Middle-Late Ordovician.Fossil occurrences and their palaeobiogeographical evolution provide critical evidence bearing on the reconstruction of the geological history of the Qinghai-Tibetan Plateau and surrounding terranes in northeastern peri-Gondwana.The stratigraphical successions of the Cambrian-Ordovician transition in the Himalaya and Lhasa and nearby Sibumasu terranes were significantly affected by the Kurgiakh Orogeny,which resulted in the extensive unconformity between the Ordovician and the underlying rocks in most areas of the Qinghai-Tibetan Plateau.In southern Xizang,a warm-water biota of Middle Ordovician age was recovered from oolitic limestones,suggesting a likely palaeogeographical location in low-latitudes near the equator.In the Himalaya and Sibumasu regions,the Upper Ordovician was typified by the occurrence of red carbonates with distinctive

关键词： Ordovician Chronostratigraphy Lithostratigraphy Biostratigraphy Palaeobiogeography Qinghai-Tibetan Plateau

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Multiple isotopes reveal the driving mechanism of high NO_(3)^(-) level and key processes of nitrogen cycling in the lower reaches of Yellow River

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Journal of Environmental sciences 2024年第4期138卷 597-606页

作者： Qianqian Zhang Huiwei Wang Lu Liu Tianlun Zhai Xueqing Zhang Hebei and China geological Survey Key Laboratory of Groundwater Remediation Institute of Hydrogeology and Environmental GeologyChinese Academy of Geological SciencesHebei 050061China Geo-Environmental Monitoring Institute of Hebei Province Hebei 050011China Hebei Provincial Laboratory of Water Environmental Science Hebei 050037China Hebei Provincial Academy of Ecological Environmental Science Hebei 050037China

The continuous increase of nitrate(NO_(3)^(-))level in rivers is a hot issue in the world.However,the driving mechanism of high NO_(3)^(-)level in large rivers is still lacking,which has limited the use of river water and increased the cost of water treatment.In this study,multiple isotopes and source resolution models are applied to identify the driving mechanism of high NO_(3)^(-)level and key processes of nitrogen cycling in the lower reaches of the Yellow River(LRYR).The major sources of NO_(3)^(-)were sewage and manure(SAM)in the low-flow season and soil nitrogen(SN)and chemical fertilizer(CF)in the high-flow season.Nitrification was the most key process of nitrogen cycling in the LRYR.However,in the biological removal processes,denitrification may not occur significantly.The temporal variation of contributions of NO_(3)^(-)sources were estimated by a source resolution model in the LRYR.The proportional contributions of SAM and CF to NO_(3)^(-)in the low-flow and high-flow season were 32.5%-52.3%,44.2%-46.2%and 36.0%-40.8%,54.9%-56.9%,respectively.The driving mechanisms of high NO_(3)^(-)level were unreasonable sewage discharge,intensity rainfall runoff,nitrification and lack of nitrate removal capacity.To control the NO_(3)^(-)concentration,targeted measures should be implemented to improve the capacity of sewage and wastewater treatment,increase the utilization efficiency of nitrogen fertilizer and construct ecological engineering.This study deepens the understanding of the driving mechanism of high nitrate level and provides a vital reference for nitrogen pollution control in rivers to other area of the world.

关键词： Nitrate Driving mechanism Nitrogen cycle Source apportionment Transformation Yellow River

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