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Geochemistry and depositional environment of fuchsite quartzites from sargur Group,western Dharwar Craton,India

Acta Geochimica 2024年第3期43卷 555-570页

作者： C.s.sindhuja G.Harshitha C.Manikyamba K.s.V.subramanyam CsIR(Council of scientific and Industrial Research)-National Geophysical Research Institute(NGRI) Uppal RoadHyderabad 500007India

Meso-Neoarchean fuchsite quartzites are present in different stratigraphic positions of Dharwar Craton including the oldest(~3.3 Ga)sargur Group of western Dharwar *** present study deals with the petro-graphic and geochemical characteristics of the fuchsite quartzites from the Ghattihosahalli belt to evaluate their genesis,depositional setting and the enigma involved in the ancient sedimentation *** major mineral assemblages include quartz,fuchsite,and feldspars along with accessory kyanite and *** geochemical com-positions are characterized by high siO_(2),Al_(2)O_(3),low MgO,CaO,strongly enriched Cr(1326–6899 ppm),Ba(1165–3653 ppm),sr(46–210 ppm),V(107–868 ppm)and Zn(11–158 ppm)contents compared to the upper continental crust(UCC).The UCC normalized rare earth element(ree)patterns are characterized by depleted light ree[(La/sm)UCC=0.33–0.95]compared to heavy ree[(Gd/Yb)_(UCC)=0.42–1.65]with conspicuous positive Eu-anomalies(Eu/Eu^(*)=1.35–18.27)characteristic of hydrothermal solutions evidenced through the interlayered *** overall major and trace element systematics reflect a combined mafic-felsic provenance and suggest their deposition at a passive continental margin *** comprehensivefield,petrographic,and geo-chemical studies indicate that these quartzites are infiltrated by Cr-richfluids released during high-grade metamorphism of associated ultramafic *** sargur and the subse-quent Dharwar orogeny amalgamated diverse lithounits from different tectonic settings,possibly leading to the release of Cr-richfluids and the formation of fuchsite quartzite during or after the *** sug-gest a pre-existing stable crust prior to the sargur Group and the link between orogenic events and various mineral deposits in the Dharwar Craton.

关键词： Dharwar Craton Ghattihosahalli Fuchsite quartzite Provenance Depositional setting

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Provenance and depositional setting of the Late MiocenePleistocene clastic sediments in the eastern Arabian Peninsula and western Iraq using rare earth elements geochemistry

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Acta Geochimica 2024年第2期43卷 399-410页

作者： salih M.Awadh Zinah s.Al-Ankaz Mohanad R.A.Al-Owaidi John s.Armstrong-Altrin Department of Geology College of ScienceUniversity of BaghdadBaghdadIraq Department of Geology College of ScienceUniversity of WasitWasit 52011Iraq Department of Applied Geology College of ScienceUniversity of BabylonBabylon 51001Iraq Unidad de Procesos Oceanicos y Costeros Instituto de Ciencias del Mar y LimnologíaUniversidad Nacional Autonoma de MexicoCiudad Universitaria04510 Mexico CityCDMXMexico Department of Marine sciences Bharathidasan UniversityTiruchirapalliTamil Nadu 620024India

The sandstones of the Late miocene–Pliocene Dibdibba Formation in the Najaf–Karbala Plateau and Basra were examined to determine their source rocks and origin. The rare earth elements.ree) and trace elements(sc, Co, V, and Th) concentrations in these sandstones revealed that they likely derived from a single source. The steep light rare earth elements(Lree) and flat, heavy rare earth element(Hree) patterns, negative Eu anomaly, and high Σree contents in sandstones suggest its derivation from a suggests that a passive continental margin environment and originated from felsic source rocks. The average concentration of Σree is 93.5 ppm, which is lower than that of the average crustal compositions like Upper Continental Crust and Post Archean Australian shale. The higher proportion of Lree compared to Hree implies that these sandstones were recycled and derived from a distal source. The Th/Co, Th/sc, La/sc, La/Co, Eu/Eu*and(La/Lu)cn elemental ratios indicated that these Late Miocene–Pliocene sandstones were derived from felsic rocks located in the marginal region of the Arabian shield.

关键词： ree Dibdibba formation Clastic sediments Passive continental margin

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Molecular phylogeny of solms-laubachia(Brassicaceae) s.l.,based on multiple nuclear and plastid DNA sequences,and its biogeographic implications

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Journal of systematics and Evolution 2009年第5期47卷 402-415页

作者： David A.BAUM Ihsan A.AL-sHEHBAZ Richard ree Department of Botany University of Wisconsin Missouri Botanical Garden PO Box 299St LouisMO 63166-0299USA 3. Department of BotanyThe Field Museum1400 S.Lake Shore DriveChicagoIL 60605USA

The Hengduan Mountains region of south-west China is a noted biodiversity hotspot,but the geographic origins and historical assembly of its rich endemic flora,including the sky-island species of solms-laubachia Muschl.(Brassicaceae),have been little *** molecular studies on the phylogeny of solms-laubachia showed it to be paraphyletic,leading to considerable expansion not only of its taxonomic limits,but also its geographic range,with the inclusion of taxa from outside the Hengduan ***,these studies provided little resolution of interspecific relationships,preventing inferences about historical biogeography within the *** the present study,new sequence data from two nuclear genes(LEAFY and G3pdh) and two chloroplast intergenic spacers(petN-psbM and psbM-trnD) were combined with existing markers to increase phylogenetic *** villosum(Maxim.) Al-shehbaz was found to be nested within solms-laubachia *** general,phylogenetic relationships appear to be a good predictor of geography,with the Hengduan Mountain endemics embedded in a paraphyletic grade of species from the western Himalayas and central Asia,but they also imply morphological *** was detected between the nuclear and chloroplast gene trees,perhaps resulting from incomplete lineage sorting of ancestral *** crown age of solms-laubachia *** estimated to be approximately 1.42-3.68 mya,using Bayesian relaxed molecular clock *** biogeographic analysis using a parametric dispersal-extinction-cladogenesis model inferred central Asia and the western Himalayas as most probable ancestral range of solms-laubachia s.l.,and estimated higher rates of eastward expansion than westward during the diversification of descendant *** summary,our results suggest that solms-laubachia *** during the Pliocene in central Asia,and subsequently migrated eastward into the Hengduan Mountains,colonizing sky-island,alpine scr

关键词： biogeography Brassicaceae Hengduan Mountains phylogeny solms-laubachia s.l.

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试用动态仿真模拟热力发电厂系统

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河北电力技术 1993年第4期12卷 76-78页

作者：诺曼.s.ree 高建强 B&W核服务公司华北电力学院仿控所

热力发电厂是一个庞大的非线性系统,且受其组成部件相互之间的多种影响。动态仿真是跟踪这些影响的强有力的手段。当更换部件,改变操作步骤,或培训运行人员时,仿真可以回答其中会遇到的问题。采用本文讨论的模块化系统模拟方法(MMs),可... 详细信息

热力发电厂是一个庞大的非线性系统,且受其组成部件相互之间的多种影响。动态仿真是跟踪这些影响的强有力的手段。当更换部件,改变操作步骤,或培训运行人员时,仿真可以回答其中会遇到的问题。采用本文讨论的模块化系统模拟方法(MMs),可提高使用者的效率,缩短开发动态仿真所需的时间。

关键词：动态仿真发电厂模拟方法

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Geochemical and petrological studies of high sulfur coal and overburden from Makum coalfield (Northeast India) towards understanding and mitigation of acid mine drainage

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International Journal of Coal science & Technology 2024年第1期11卷 133-147页

作者： Angana Mahanta Debashis sarmah Nilotpol Bhuyan Monikankana saikia sarat Phukan K.s.V.subramanyam Ajit singh Prasenjit saikia Binoy K.saikia Coal and Energy Division CSIR-North East Institute of Science and TechnologyJorhatAssam785006India Academy of scientific&Innovative Research(AcsIR) Ghaziabad201002India Department of Geological sciences Gauhati UniversityGuwahatiAssam781014India Geochemistry Division CSIR-National Geophysical Research InstituteUppal RoadHyderabad500007India

Opencast coal mining produces trash of soil and rock containing various minerals,that are usually dumped nearby the abandoned sites which causes severe environmental concern including the production of acid mine drainage(AMD)through oxidation pyrite *** current study entailed assessing the potential production of AMD from an opencast coal mining region in Northeast part of *** order to have a comprehensive overview of the AMD problem in Makum coalfield,the physico-chemical,geochemical,and petrological characteristics of the coal and overburden(OB)samples collected from the Makum coalfield(Northeast India)were thoroughly *** maceral compositions reveal that coal features all three groups of macerals(liptinite,vitrinite,and inertinite),with a high concentration of liptinite indicating the coal of perhydrous,thereby rendering it more ***(Fes_(2))oxidation kinetics were studied by conducting the aqueous leaching experiments of coal and(OB)samples to interpret the chemical weathering under controlled laboratory conditions of various temperature and time periods,and to replicate the actual mine site *** coupled plasma-optical emission spectroscopy(ICP-OEs)was operated to detect the disposal of some precarious elements from coal and OB samples to the leachates during our controlled leaching *** Rare earth element(ree)enrichment in the samples shows the anthropogenic incorporation of the ree in the coal and *** experiments reveal the change in conductivity,acid producing tendency,total dissolved solid(TDs),total Iron(Fe)and dissolved sulfate(sO_(4)^(2−))ions on progress of the leaching ***,the discharge of Fes_(2) via atmospheric oxidation in laboratory condition undergoes a significant growth with the rise of temperature of the reaction systems in the environment and follows pseudo first order kinetics.A bio-remediative strategies is also reported in this paper to mitigate AMD water by

关键词： Opencast mining Pyrite oxidation Coal geochemistry Coal petrology Rare earth elements AMD remediation

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Petrographic and Geochemical Characteristics of the Granitoids in the south of Godé (North of the square Degree of Léo-Burkina Faso, West Africa)

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International Journal of Geosciences 2024年第2期15卷 106-118页

作者： Adama Ouédraogo Yaméogo Hubert Gounwendmanaghré Zongo Pascal Ouiya Omar Akonyiré Abraham seydoux Traoré saga sawadogo séta Naba Unité de Formation et de Recherche en sciences et Technologies Département des Sciences de la Vie et de la Terre Université Norbert Zongo Koudougou Burkina Faso Unité de Formation et de Recherche en sciences de la Vie et de la Terre Laboratoire Géosciences et Environnement (LaGE) Départe-ment des Sciences de la Terre Université Joseph Ki-Zerbo Ouaga Burkina Faso Ecole supérieure d’Ingénieries Université de Fada N’gourma Fada N’Gourma Burkina Faso Ecole Normale supérieure (ENs)/Institut des sciences et de Technologie (IsT) Ouaga Burkina Faso

south of Godé, in the central-western region of Burkina Faso, granitoids of Paleoproterozoic age are similar to those of the Man/Leo shield. This study focused on the petrographic and geochemical characteristics of these granitoids, with the following results: 1) The tonalite that outcrops in the south-west of the study area belongs to the TTG group or first generation granitoids. They are most often ribboned at outcrop and have a geochemical signature close to that of Archean TTGs. Tonalite has a metaluminous character and the ree spectrum indicates that it may be derived from partial melting of basic magmatic rocks. 2) Biotite granites have no outcrop structure. They are weakly metaluminous to peraluminous and potassic to highly potassic. Their rare earth spectra indicate that they may be derived from the partial melting of TTG granitoids. 3) Geotectonic diagrams show that the granitoids studied to the south of Godé were emplaced in an active tectonic context similar to that of present-day subduction zones.

关键词： Burkina Faso Godé Man/Leo shield Petrography Geochemistry Partial Melting Geotectonic setting

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Neoproterozoic U-Th-ree-bearing Pegmatites in Wadi Ibib, south Eastern Desert, Egypt: structural and Geochemical Measures for a syn-Tectonic Anatectic Model of Formation

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Acta Geologica sinica(English Edition) 2021年第6期95卷 2045-2062页

作者： Waleed s.IBRAHIM Nuclear Materials Authority El MaadiCairoEgypt

The Wadi Ibib area is situated in the northern part of the Neoproterozoic Hamisana shear Zone(HsZ), which is a high strain zone evolved during the late stages of the Pan-African orogeny, likely as a tectonic escape structure. Amphibolite facies pelitic metasedimentary windows crop out in the axial parts of the HsZ and are noticeably associated with numerous N-trending pegmatite dikes. Whole-rock geochemistry of the pegmatites reveals a peraluminous(s-type) affinity, with low K/Rb ratios and elevated concentrations of U, Th, ree, Rb, Li, Cs, Y, Nb and Ta. structurally, the pegmatite sets intrude along the shear plane of the HsZ, corresponding to the regional N-trending tectonic fabrics, such as axial planar foliation and dextral-shearing in the metasedimentary host rock. Field relationships, including structural context, coupled with geochemical characteristics of the Wadi Ibib pegmatites, do not support their formation as a complementary part of evolved granitic magmas. space-localized decompression-induced partial melting of peraluminous garnet-bearing metapelites was alternatively the underlying process for formation of these pegmatites. such decompression was associated with regional escape tectonics and stress axes permutations during the late deformation stage(D3) in the evolution of the south Eastern Desert terrane, due to end-orogeny system pressure-release.

关键词： U-Th-ree mineralization anataxis pegmatite origin Hamisana shear Zone Wadi Ibib Egypt

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Element diffusion ability in metasomatic agents and its effect on chemical characteristics of metasomatized peridotites

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science China Earth sciences 2006年第9期49卷 926-937页

作者： Y s O’Reilly GEMOC ARC National Key Centre Department of Earth and Planetary Sciences Macquarie University Sydney N.S.W. 2109 Australia

Detailed in situ LM-ICPMs researches on the composite xenoliths from Yingfengling volcano of Leizhou Peninsula, south China, indicate that most incompatible trace elements of clino- pyroxenes in composite xenoliths decrease spatially from pyroxenites to distal lherzolites, and com- patible elements and Hree increase steeply. The increasing and decreasing rate is distinct for dif- ferent trace elements, which give rise to element chromatographic fractionation within metasomatized lherzolites. The element chromatographic fractionation result actually from the difference in element diffusive rate in melts or fluids percolating through wall-rock lherzolites. Based on element variation profiles in composite xenoliths this study indicates that sr, Nb, La and Ce have the highest diffusive mobility, Mree-Hree are moderate, and Zr, Hf, Ti, Ga and sc are very low in most cases. Higher diffusive rates of Lree than Hree would enlarge the ree fractionation of metasomatized peridotites, and lower diffusive rate of Zr, Hf and Ti relative to neighbor rees with similar incompatibility would cause the relative depletion of these elements in metasomatized peridotites. Trace elements com- monly have a higher diffusive rate in fluid-rich infiltrating melt, which will weaken element chroma- tographic fractionation during the metasomatism. The range of mantle metasomatism caused by sili- cate melt intrusion is very limited, generally within tens of centimeters wide. The width of metasoma- tized wall-rock peridotites near the pyroxenite or horblendite veins was strictly controlled by both melt volume and chemical characteristics.

关键词： composite xenolith, metasomatism, chromatographic fractionation, diffusive rate, Leizhou Peninsula.

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Detrital zircon U-Pb geochronology and geochemistry of the Riachuelos and Palma sola beach sediments,Veracruz state,Gulf of Mexico:a new insight on palaeoenvironment

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Journal of Palaeogeography 2020年第4期9卷 495-521页

作者： John s.Armstrong-Altrin Unidad de Procesos Oceánicos y Costeros Instituto de Ciencias del Mar y LimnologíaUniversidad Nacional Autónoma de MéxicoCiudad UniversitariaCiudad de México 04510México

Zircons are abundant in the beach *** this study,surface microtexture,mineralogy,bulk sediment geochemistry,trace element composition and U−Pb isotopic geochronology of detrital zircons collected from the Riachuelos and Palma sola beach areas,southwestern Gulf of Mexico were performed to infer the sediment provenance and *** zircon microtexture was categorized as mechanically-and/or chemically-induced *** weathering index values for the Riachuelos(~72−77)and Palma sola(~71−74)beach sediments indicated moderate weathering of both of the two source *** major and trace element data of bulk sediments suggested passive margin settings for the two *** trace elemental ratios and chondrite-normalized rare earth element(ree)patterns of bulk sediments revealed that the sediments were likely sourced by felsic and intermediate igneous *** the zircon Th/U ratios(mostly more than 0.2)and zircon ree patterns(with negative Eu and positive Ce anomalies)suggested a magmatic origin for both of the beach sediments from these two *** distinct zircon age peaks respectively belonging to the Paleozoic and the Cenozoic were identified both in the Riachuelos and Palma sola beach *** geochronology comparison research between the Riachuelos−Palma sola beach sediments and potential source areas in sW Gulf of Mexico revealed that the source terrane supplied the Paleozoic zircons of this study was identified as the Mesa Central Province(MCP),and the Cenozoic zircons were transported from the nearby Eastern Alkaline Province(EAP).Moreover,although the Precambrian zircons were very few in the studied sediments,their geochronology and geochemistry results still could infer that they were contributed by the source terranes of Grenvillian igneous suites in the Oaxaca and the Chiapas Massif Complexes.

关键词： Detrital zircon Beach sediment U-Pb dating Zircon grain morphology Microtexture Mineralogy Geochemistry Geochronology Gulf of Mexico

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Comparison of mantle lithosphere beneath early Triassic kimberlite fields in siberian craton reconstructed from deep-seated xenocrysts

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Geoscience Frontiers 2016年第4期7卷 639-662页

作者： I.V.Ashchepkov s.s.Kuligin N.V.Vladykin H.Downes M.A.Vavilov E.N.Nigmatulina s.A.Babushkina N.s.Tychkov O.s.Khmelnikova lnstitute of Geology and Mineralogy sD RAs Koptyug ave 3NovosibirskRussia Institute of Geochemistry sD RAs Favorskky str laIrkutskRussia Department of Earth and Planetary sciences Birkbeck University of LondonLondonUK Institute of Geology of Diamonds and Noble metals sD RAs Lenina ave 39YakutskRussia

Mantle xenocrysts from early Triassic kimberlite pipes from Kharamai, Ary-Mastakh and Kuranakh fields in the Anabar shield of siberia revealing similar compositional trends were studied to estimate the superplume influence on the subcratonic lithosphere mantle （sCLM）. Pressure-temperature （PT） reconstructions using monomineral thermobarometry for 5 phases show division of the sCLM beneath the Kharamai field into 6 units： pyroxenitic Fe-rich （1-2 GPa） and Mg-rich （2-3 GPa） layers; middle with two levels of Gar-sp pyroxenites at - 3 and 4-5 GPa; Gar-dunite-harzburgites - 4.5-6.5 GPa subjected to llm-Px vein metasomatism; and a Mg-rich dunite lower part. In the Anabar shield （Ary-Mastakh, Dyuken and Kuranakh fields） mantle lithosphere is composed of three large units divided into two parts： upper part with amphiboles and phlogopite; two levels of pyroxenites and eclogites at 3 and 4 GPa, and a lower part composed of refertilized dunites. Diagrams showing P-Fe#Gar clusters for garnets and omphacites illustrate the differences between sCLM of these localities. Differences of Triassic sCLM from Devonian sCLM are in simple layering; abundance of Na-Cr-amphiboles and metasomatism in the upper sCLM part, thick pyroxenite-eclogite layer and lower part depletion, heated from sCLM base to 5.0 GPa. Kharamai mantle clinopyroxenes represent three geochemical types：（1） harzburgitic with inclined linear ree, HFsE troughs and elevated Th, U; （2） lherzolitic or pyroxenitic with round TRE patterns and decreasing incompatible elements; （3） eclogitic with Eu troughs, Pb peak and high LILE content. Calculated parental melts for garnets with humped ree patterns suggest dissolution of former Cpx and depression means Cpx and garnets extraction. Clinopyroxenes from Ary-Mastakh fields show less in- dined ree patterns with HMree troughs and an increase of incompatible elements. Clinopyroxenes from Kuranakh field show flatter spoon-like ree patterns and peaks in Ba, U, Pb and st, similar to th

关键词： Mantle lithosphere Monomineral thermobarometry Mineral geochemistry Triassic kimberlite Layering

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