检索结果-南通市图书馆

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

Provenance and tectonic setting of sandstones of the Lomas Coloradas Formation, Cabullona Group, sonora, México: Constraints on petrography and geochemistry

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2024年第4期13卷 839-861页

作者： J.Madhavaraju D.G.Noriega-Montoya E.Ramirez-Montoya C.M.Gonz alez-Le on john s.armstrong-altrin Estaci on Regional del Noroeste Instituto de GeologíaUniversidad Nacional Aut onoma de Mexico Ingeniería en Geociencias Universidad Estatal de Sonora Posgrado en Ciencias de la Tierra Estaci on Regional del NoroesteInstituto de GeologíaUniversidad Nacional Aut onoma de Mexico Universidad Nacional Aut onoma de Mexico Instituto de Ciencias del Mar y LimnologíaUnidad de Procesos Oce anicos y CosterosCiudad Universitaria

The sedimentary rocks of the Cabullona Group are well exposed in the Cabullona Basin of northeastern sonora, Mexico, which represent syntectonic sedimentation associated with Laramide-style deformation during the Campanian-early Maastrichtian. The sandstones of the Lomas Coloradas Formation deposited at the upper part of the Cabullona Group. Petrography and geochemical(major, trace, and rare earth elements) studies were carried out on the sandstones to interpret the palaeoweathering, provenance,and tectonic setting of the Lomas Coloradas Formation sandstones. Most of the sandstone modal analysis data plotted in the QFL and Qm FLt ternary diagrams fall into the fields of dissected arcs and recycled orogens,respectively. Geochemically the sandstones are classified as litharenites while few samples plot into the arkosic field. The chondrite-normalized REE diagrams for sandstones have LREE-enriched, relatively flat HREE patterns with negative Eu anomalies. CIA values and the A-CN-K diagram indicate a low intensity of chemical weathering in the source area. The tectonic setting diagram suggests both arc and rift settings for the studied sandstones. The bivariate and ternary diagrams and elemental ratios suggest a felsic source for the Lomas Coloradas Formation. The average REE patterns of the studied sandstones are comparable with REE patterns of the granite from the Caborca block, the rhyolite and granite of the Tarahumara Formation, and the Mesozoic felsic volcanic rocks. The modeled mixture of 40% Proterozoic granite, 30% Triassic arc, 10% Jurassic arc, and 20% Laramide arc represents the probable source rocks for the Lomas Coloradas Formation.

关键词： Provenance Petrography Geochemistry Lomas Coloradas Formation Cabullona Group Mexico

Geochemistry and mineralogy of beach sediments in the northern Gulf of Mexico,Tamaulipas state,Mexico:implication for provenance

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2024年第3期13卷 375-400页

作者： Mayank shukla sanjeet K.Verma Mayla A.Ramos-Vázquez john s.armstrong-altrin Karla R.Hernández-Martínez sumit Mishra Vivek P.Malviya Héctor Hernández-Mendoza Posgrado de la Division de Geociencias Aplicadas Instituto Potosino de Investigacion Científica y Tecnologica(IPICYT)Camino a la Presa San José2055San Luis Potosí78216Mexico Division de Geociencias Aplicadas Instituto Potosino de Investigación Científica y Tecnologica(IPICYT)Camino a la Presa San Jose 2055San Luis Potosí78216Mexico Universidad Nacional Autonoma de México Instituto de Ciencias del Mar y LimnologíaUnidad de ProcesosOceanicos y CosterosCiudad UniversitariaCiudad de México 04510Mexico Department of Marine sciences Bharathidasan UniversityTiruchirappalli620024Tamil NaduIndia Instituto de Geociencias Universidad Nacional Autonoma de MéxicoBoulevard Juriquilla 300176230JuriquillaQueretaroMexico Department of Applied Geology Dr.Harisingh Gour Central UniversitySagar470002Madhya PradeshIndia Instituto de Investigacion de Zonas Desérticas Universidad Autònoma de San Luis PotosíAltair 200CP 78377San LuisS.L.P.Mexico Universidad del Centro de Mexico Capitán Caldera 75CP 78250San LuisS.L.P.Mexico

Geochemical and mineralogical studies were performed in the La Pesca(LP)and Tesoro Altamira(TA)beach sediments,located in the Tamaulipas state,northern Gulf of *** main aim of this study is to infer the weathering history and provenance and to discriminate the tectonic environment of the beach *** sediments are composed of quartz with small amounts of accessory minerals such as plagioclase,calcite,orthoclase,microcline,and *** beach sediments are classified as fine-grained and very well sorted,however LP has coarse skewed and leptokurtic sediments,whereas TA has fine-skewed and very leptokurtic *** chemical index of weathering(CIW’)indicates intense weathering in the source *** quartz grain microtextures in the LP and TA are classified into mechanical,chemical,and mechanical/chemical *** features such as fractures,pits,percussion marks,abrasion fatigue,and V-shaped marks favor high-energy littoral,fluvial,subaqueous-marine,and aeolian *** chemical features indicate solution pits and crystalline overgrowth,which suggests a silica saturated marine *** mechanical/chemical features display adhering particles and elongated depressions suggest formation in a sub-aqueous nearshore marine *** and trace elements-based provenance discrimination diagrams indicate a felsic source derived from the Mesa Central(MC),sierra Madre Oriental(sMOr)and Oaxaquia *** major and trace element concentrations imply a passive margin setting for the northern Gulf of Mexico,which is consistent with the general geology.

关键词： Beach sediments Geochemistry Mineralogy Provenance Tamaulipas Tectonic setting

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

在线全文

学校读者我要写书评

暂无评论

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

Provenance of sediments from Barra del Tordo and Tesoro beaches, Tamaulipas state, northwestern Gulf of Mexico

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2021年第3期10卷 382-398页

作者： Mayla A.Ramos-Vazquez john s.armstrong-altrin Posgrado en Ciencias del Mar y Limnologpa Universidad Nacional Autonoma de MexicoCiudad UniversitariaCiudad de Mexico 04510Mexico Universidad Nacional Autonoma de Mexico Instituto de Ciencias del Mar y LimnologiaUnidad de Procesos Oceanicos y CosterosCiudad UniversitariaCiudad de Mexico 04510Mexico

The mineralogy, bulk sediment geochemical composition, and U–Pb ages of detrital zircons retrieved from the Barra del Tordo(Tordo) and Tesoro beach sediments in the northwestern Gulf of Mexico were analyzed to determine their provenance. The beach sediments are mainly composed of quartz, ilmenite, magnetite, titanite,zircon, and anorthite. The weathering proxies such as the Chemical Index of Alteration(CIA), Chemical Index of Weathering(CIW), and Plagioclase Index of Alteration(PIA), reveal a moderate-to-high intensity of weathering in the source area. The chondrite-normalized rare earth element(REE) patterns are similar to felsic igneous rocks, with large negative europium anomaly(Eu/Eu^(*)= ~ 0.47–0.80 and ~ 0.57–0.67 in the Tordo and Tesoro beach sediments,respectively).Three major zircon U–Pb age groups are identified in the Tordo and Tesoro beach sediments, i.e., Proterozoic(~2039–595 Ma), Mesozoic(~ 244–70.3 Ma), and Cenozoic(~ 65.9–1.2 Ma). The differences of the zircon age spectrum between the Tordo and Tesoro beach sediments are not significant. The comparison of zircon U–Pb ages in this study with ages of potential source terranes suggests that the Mesozoic and Cenozoic zircons of the studied Tordo and Tesoro beach sediments were derived from the Eastern Alkaline Province(EAP) and Mesa Central Province(MCP). similarly, the likely sources for the Proterozoic zircons were the sierra Madre Oriental(sMOr) and Oaxaquia in the northwestern Gulf of Mexico. The results of this study further indicate that the sediments delivered to the beaches by rivers and redistributed by longshore currents were crucial in determining the sediment provenance.

关键词： Geochemistry sedimentary provenance Zircon U–Pb Beach sediment Rare earth elements Mexico

Textural and geochemical characteristics of late Pleistocene to Holocene fine-grained deep-sea sediment cores(GM6 and GM7),recovered from southwestern Gulf of Mexico

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2018年第3期7卷 253-271页

作者： Abigail Anaya-Gregorio john s.armstrong-altrin Marfa Luisa Machain-Castillo Patricia C.Montiel-Garcia Mayla A.Ramos-Vazquez Licenciatura en Ingenieria en Geologia Ambiental Area Academica de Ciencias de la Tierra y MaterialesUniversidad Autonoma del Estado de HidalgoMineral de la ReformaHidalgoMexico. Instituto de Ciencias del Mary Limnologia Universidad Nacional Autenoma de MexicoUnidad de Procesos Oceanicos y CosterosCiudad Universitaria04510 Ciudad de MexicoMexico. Area Academica de Ciencias de la Tierra y Materiales Universidad Autonoma del Estado de HidalgoCiudad UniversitariaCarretera Pachuca-Tulancingo Km 4.5Col.CarbonerasC.P.42184 Mineral de la ReformaHidalgoMexico. Posgrado en Ciencias del Mary Limnologia Universidad Nacional Autonoma de MexicoCiudad Universitaria3000CoyoacanC.P.04510 Ciudad de MexicoMexico.

Texture, mineralogy, geochemistry, and 14C ages of two deep-sea sediment cores （GM6 and GM7） recovered in the southwestern Gulf of Mexico were investigated to infer their provenance and depositional condition. The sediments are enriched in fine-grained silt and clay and poor in sand content. Mineralogically, the sediments consist of quartz, calcite, smectite, and kaolinite. Based on the ]4C data, the age of the GM6 and GM7 sediment cores were calculated as 23,615 cal yrs. BP and 19,007 cal yrs. BP, respectively. The weathering indices such as chemical index of alteration （CIA）, chemical index of weathering （CIW）, and plagioclase index of alteration （PIA） in GM6 （56-69, 60-74, and 6]-73, respectively） and GM7 （54-69, 57-76, and 55-74, respectively） cores revealed a moderate-to-high intensity of weathering. The rare earth element （REE） patterns suggested that the sediments were derived mostly by the weathering of intermediate rocks, exposed along the coastal regions of the Gulf of Mexico. The trace elemental ratios like V/Cr （〈2）, Ni/Co （〈2）, and Cu/Zn （〈1）, authigenic uranium content （〈1）, and Ce anomaly （Ce/Ce＊ ≤1） suggested that the sediments were deposited under an oxic condition, which was also revealed by the benthic foraminiferal assemblages throughout the GM6 and GM7 sediment cores.

关键词： Radiocarbon age Manganosite Weathering Palaeoredox condition Provenance Holocene Gulf of Mexico

Microtextures on quartz grains from the Gulf of Mexico and the Mexican Pacific coastal sediments:Implications for sedimentary processes and depositional environment

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2022年第2期11卷 256-274页

作者： Jayagopal Madhavaraju john sarmstrong-altrin Kandasamy selvaraj Rathinam Arthur James Estaci on Regional Del Noroeste Instituto de GeologíaUniversidad Nacional Aut onoma de MexicoHermosilloSonora 83000Mexico Universidad Nacional Aut onoma de Mexico Instituto de Ciencias Del Mary LimnologíaUnidad de Procesos Oce anicosy CosterosCiudad UniversitariaCiudad de Mexico 04510Mexico Department of Geological Oceanography and state Key Laboratory of Marine Environmental science College of Ocean and Earth SciencesXiamen UniversityXiamen UniversityXiamenChina Department of Marine science Bharathidasan UniversityTiruchirapalli620024Tamil NaduIndia

Microtexture analyes on quartz from coastal sediments of the Gulf of Mexico and the Mexican Pacific Coast reveal 35 and 30 types of microtextures,respectively,which were grouped into mechanical,mechanical/chemical and chemical categories based on their mode of *** of chemical origin are rarer in the El Carrizal than in the Manzanillo beach sediments of the Mexican Pacific *** of mechanical origin like straight and curved scratches,pits,broken edges,and V-shaped marks indicate high energy,fluvial to marine depositional *** scarcity to absence of chemical features suggest that the energy level was higher at the Mexican Pacific coast than on the Gulf of Mexico coast.V-shaped marks are common in the Gulf of Mexico sediments,whereas they are abundant in the quartz grains from the Mexican Pacific *** frequency and density of V-shaped marks are produced by exceedingly high wave velocity during storm events or *** of V-shaped marks with fresh surfaces of quartz grains from the Mexican Pacific coast indicate an extremely high-energy impact *** quartz grains from the El Carrizal beach of the Mexican Pacific coast have abundant closely spaced Vshaped marks with fewer fresh *** high frequency of V-shaped marks is mainly linked to grain-tograin collision,typically associated with high-energy sub-aqueous conditions with a large volume of sedimentary particles in the water column that are produced during a tsunami or storm *** contrast,many quartz grains from the Gulf of Mexico have large fresh surfaces with moderate percentages of V-shaped marks that might have been produced by high-energy waves with low sediment concentrations during storm events.

关键词： Microtextures Quartz grains V-shaped marks Tsunami and storm events sedimentary processes

Mineralogy and geochemistry of the Ngaoundaba Crater Lake sediments,northern Cameroon:implications for provenance and trace metals status

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2021年第5期40卷 718-738页

作者： Armel Zacharie Ekoa Bessa john sarmstrong-altrin Gentry Calistus Fuh Thierry Bineli Betsi Tebogo Kelepile Paul-DesireNdjigui Department of Earth sciences University of Yaounde IP.O.Box 812YaoundeCameroon Universidad Nacional Autonoma de Mexico Instituto de Ciencias del Mar Y LimnologıaUnidad de Procesos Oceanicos y CosterosCircuito exterior s/n04510 MexicoD.F.Mexico Department of Mining and Geological Engineering Botswana International University of Sciences and TechnologyPrivate Bag 16PalapyeBotswana

This study was conducted on the Ngaoundaba Crater Lake sediments to infer provenance,weathering conditions,organic matter accumulation,and trace metal *** Lake sediments were collected using a manual core sampler at 5 to 8 m water *** sediment cores from the littoral and center of the lake were analyzed for grain size distribution,water content(WC),organic matter content,mineralogy,and major and trace element *** Ngaoundaba sediments were classified as silt and sandy *** show high content in organic matter,which is more to the littoral than to the center of the lake,varying from 14.6%to 24%and21.2%to 40.8%,*** grain surface features identified by scanning Electron Microscopy(sEM)show both chemical and mechanical microtextures with subrounded to angular shape suggesting both proximal and distal *** lake sediments are composed of quartz,kaolinite,and hematite,with low amounts of feldspars,rutile,calcite,illite,and *** indices such as the chemical index of alteration(CIA),chemical index of weathering(CIW),and index of compositional variability(ICV)indicate moderate to intense chemical weathering in the source area and immature to mature *** geochemical composition indicates that the sediments were derived from felsic to intermediate igneous rocks,such as granitoids,and mafic alkali lavas like *** environmental risk assessment of trace metals obtained by enrichment factor(EF)and geo-accumulation index(I-geo)shows low contamination of the lake sediments.

关键词： Ngaoundaba Crater Lake Mineralogy Geochemistry Provenance Metal traces status

study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 677-694页

作者： A.s.john B.MAHANTHEsH G.LORENZINI Center for Mathematical Needs Department of MathematicsCHRIST(Deemed to be University)Karnataka 560029India school of Mathematical and statistical sciences The University of Texas Rio Grande ValleyTexas 78539U.S.A. Department of Engineering and Architecture University of ParmaParma 43124Italy

Cone-disk systems find frequent use such as conical diffusers,medical devices,various rheometric,and viscosimetry *** this study,we investigate the three-dimensional flow of a water-based Ag-Mg O hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid *** the variable fluid properties affect the dynamics and heat transfer features is studied by Reynolds's linearized model for variable viscosity and Chiam's model for variable thermal *** single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids,incorporating the experimental *** model is developed as a coupled system of convective-diffusion equations,encompassing the conservation of momentum and the conservation of thermal energy,in conjunction with an incompressibility condition.A self-similar model is developed by the Lie-group scaling transformations,and the subsequent self-similar equations are then solved *** influence of variable fluid parameters on both swirling and non-swirling flow cases is ***,the Nusselt number for the disk surface is *** is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system,while the thermal conductivity parameter has the opposite effect.

关键词： hybrid nanofluid cone-disk system laminar flow variable fluid property Nusselt number

Optimizing oncolytic virus design:a“swiss army knife”approach to create a systemically delivered therapeutic

在线全文

学校读者我要写书评

暂无评论

signal Transduction and Targeted Therapy 2024年第5期9卷 1791-1792页

作者： Carolina s.Ilkow john Cameron Bell Ottawa Hospital Research Institute 501 Smyth RoadOttawaONK1H 8L6Canada

In a recent paper published in Nature Biotechnology,Chen et al.1 describe a multiplex oncolytic virus platform that coupled with adoptive T cell therapy could solve the problem of repeat,systemic delivery of virus based *** is widely accepted that multi-targeted therapeutic approaches attacking several facets of cancer biology are necessary to effectively deal with the tumor heterogeneity that exists within and between patients.

关键词： therapeutic al. targeted