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Strength Elements (strength + element)

Distribution by Scientific Domains
Earth and Environmental Science77%

Kinds of Strength Elements

  • field strength element
    		•
  • high field strength element
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    Selected Abstracts

    Olivine-spinifex basalt from the Tamba Belt, southwest Japan: Evidence for Fe- and high field strength element-rich ultramafic volcanism in Permian Ocean

    ISLAND ARC, Issue 3 2007
    Yuji Ichiyama
    Abstract Permian basalt showing typical spinifex texture with >10 cm-long olivine pseudomorphs was discovered from the Jurassic Tamba accretionary complex in southwest Japan. The spinifex basalt occurs as a river boulder accompanied by many ferropicritic boulders in a Permian chert-greenstone unit. Groundmass of this rock is holocrystalline, suggesting a thick lava or sill for its provenance. Minor kaersutite in the groundmass indicates a hydrous magma. The spinifex basalt, in common with the associated ferropicritic rocks, is characterized by high high field strength element (HFSE) contents (e.g. Nb = 62 ppm and Zr = 254 ppm) and high-HFSE ratios (Al2O3/TiO2 = 3.9, Nb/Zr = 0.24 and Zr/Y = 6.4) unlike typical komatiites. The spinifex basalt and ferropicrite might represent the upper fractionated melt and the lower olivine-rich cumulate, respectively, of a single ultramafic sill (or lava) as reported from the early Proterozoic Pechenga Series in Kola Peninsula. Their parental magma might have been produced by hydrous melting of a mantle plume that was dosed with Fe- and HFSE-rich garnet pyroxenite. The spinifex basalt is an evidence for the Pechenga-type ferropicritic volcanism taken place in a Permian oceanic plateau, which accreted to the Asian continental margin as greenstone slices in Jurassic time. [source]

    Influence of Potsdam sandstone on the trace element signatures of some 19th-century American and Canadian glass: Redwood, Redford, Mallorytown, and Como,Hudson

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 5 2008
    J. Victor Owen
    Potsdam sandstone from quarries and outcrops near 19th-century glassworks sites in Redwood, NY, and Saranac, NY, Mallorytown, ON, and Como and Hudson, QC, commonly contains _97% silica, so in terms of its purity can compete with other historical producers of silica sand (e.g., Cheshire quartzite, MA; southern New Jersey sand). Exploratory analysis of trace element data using multidimensional scaling (MDS) shows that geographically distinct sources of Potsdam sandstone can be distinguished from one another and from competing sources of silica sand, particularly in terms of high field strength elements (e.g., Nb, Y, Ti, Zr), the rare earth elements, and radioactive elements (U, Th), and this geochemical signature is carried through to the glass it was used to manufacture. Other trace elements (e.g., Ba, Sr, Rb) are concentrated in various batch ingredients (e.g., limestone, alkali fluxes). The Hf/Nb, La/Ce, Nb/Th, and La/Zr ratios for each type of glass and nearby Potsdam sandstone sources cluster together in distinct fields on MDS plots. These data confirm the use of Potsdam sandstone in these important historical glassworks, and show that except for material sampled from neighboring communities (Mallorytown and Redwood), trace elements can be used to identify specific sources of silica historically used by the glassmaking industry. © 2008 Wiley Periodicals, Inc. [source]

    The Cretaceous volcanic succession around the Songliao Basin, NE China: relationship between volcanism and sedimentation

    GEOLOGICAL JOURNAL, Issue 2 2002
    Pujun Wang
    Abstract With volume ratio of 8:1:1.5 amongst acidic, intermediate and basaltic rocks, the Cretaceous volcanics around the Songliao Basin are a series of high-K or medium-K, peraluminous or metaluminous, calc-alkaline rocks, lacking typical basalts and peralkaline members of typical rift-related types. Their eruption ages range between 133 and 127,Ma, 124 and 122,Ma and 117 and 113,Ma respectively. They are high in total (Rare earth element) REE contents (96.1,326,ppm), enriched in LREE and depleted in HREE (LREE/HREE,=,4.6,13.8), with negative Eu and Ce anomalies (Eu/Eu*,=,0.04,0.88; Ce/Ce*,=,0.60,0.97). They have enriched large-ion lithophile elements (e.g. K, Ba, Th) and depleted high field strength elements (e.g. Nb, Ti and Y), suggesting a subduction-related tectonic setting. The volcanic activities migrated from south to north, forming a successively northward-stepping volcanic series and showing a feature significantly different from the overlying sedimentary sequence striking northeast. Thus, an overlap basin model was proposed. Accompanied by opening of the basin, the volcanogenic succession was formed at the block-faulting stage (131,113,Ma) owing to the closure of the Mongolia,Okhotsk ocean in the Jurassic and early Cretaceous, while the overlying sedimentary sequence was unconformably deposited at the spreading stage (Albian,Maastrichtian) owing to the oblique subduction of the Pacific plate under the Eurasian plate. The volcanic succession constitutes the lower unit of basin filling and is the forerunner of further basin spreading. Copyright © 2002 John Wiley & Sons, Ltd. [source]

    Trace Elemental Analysis of Titanium Dioxide Pigments and Automotive White Paint Fragments for Forensic Examination Using High-Energy Synchrotron Radiation X-Ray Fluorescence Spectrometry,

    JOURNAL OF FORENSIC SCIENCES, Issue 3 2009
    Yoshinori Nishiwaki M.S.
    Abstract:, High-energy synchrotron radiation x-ray fluorescence spectrometry (SR-XRF) utilizing 116 keV x-rays was used to characterize titanium dioxide pigments (rutile) and automotive white paint fragments for forensic examination. The technique allowed analysis of K lines of 9 trace elements in 18 titanium dioxide pigments (rutile), and 10 trace elements in finish coat layers of seven automotive white paint fragments. High-field strength elements (HFSE) were found to strongly reflect the origin of the titanium dioxide (TiO2) pigments, and could be used as effective parameters for discrimination and classification of the pigments and paint fragments. A pairwise comparison of the finish coat layers of seven automotive white paint fragments was performed. The trace elements in the finish coat layers detected by the high-energy SR-XRF were especially effective for identification. By introducing the trace element information of primer and electrocoat layers, all the automotive white paint fragments could be discriminated by this technique. [source]

    Geochemistry and shock petrography of the Crow Creek Member, South Dakota, USA: Ejecta from the 74-Ma Manson impact structure

    METEORITICS & PLANETARY SCIENCE, Issue 1 2004
    Crispin KATONGO
    The shocked minerals represent impact ejecta from the 74-Ma Manson impact structure (MIS). This study was aimed at determining the bulk chemical compositions and analysis of planar deformation features (PDFs) of shocked quartz; for the basal and marly units of the Crow Creek Member. We studied samples from the Gregory 84-21 core, Iroquois core and Wakonda lime quarry. Contents of siderophile elements are generally high, but due to uncertainties in the determination of Ir and uncertainties in compositional sources for Cr, Co, and Ni, we could not confirm an extraterrestrial component in the Crow Creek Member. We recovered several shocked quartz grains from basal-unit samples, mainly from the Gregory 84-21 core, and results of PDF measurements indicate shock pressures of at least 15 GPa. All the samples are composed chiefly of SiO2 (29,58 wt%), Al2O3 (6,14 wt%), and CaO (7,30 wt%). When compared to the composition of North American Shale Composite, the samples are significantly enriched in CaO, P2O5, Mn, Sr, Y, U, Cr, and Ni. The contents of rare earth elements (REE), high field strength elements (HFSE), Cr, Co, Sc, and their ratios and chemical weathering trends, reflect both felsic and basic sources for the Crow Creek Member, an inference, which is consistent with the lithological compositions in the environs of the MIS. The high chemical indices of alteration and weathering (CIA' and CIW': 75,99), coupled with the Al2O3 -(CaO*+Na2O)-K2O (A-CN'-K) ratios, indicate that the Crow Creek Member and source rocks had undergone high degrees of chemical weathering. The expected ejecta thicknesses at the sampled locations (409 to 219 km from Manson) were calculated to range from about 1.9 to 12.2 cm (for the present-day crater radius of Manson), or 0.4 to 2.4 cm (for the estimated transient cavity radius). The trend agrees with the observed thicknesses of the basal unit of the Crow Creek Member, but the actually observed thicknesses are larger than the calculated ones, indicating that not all of the basal unit comprises impact ejecta. [source]

    Mineralogical and Petrological Characteristics of the Neoproterozoic Orthoamphibolite and Orthogneisses in the Mutki Area, the Bitlis Massif, Southeast Turkey

    ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2010
    Kerim KOCAK
    Abstract: The rocks form as amphibolite ± garnet ± epidote and orthogneisses in the Pan-African basement of the Bitlis Massif. The petrochemical data of the studied metamorphic rocks suggest different igneous protoliths ranging from calcalkaline basalt to andesite in composition. Petrochemically, the rocks can be classified as group 1 (low Zr and La) and group 2 (high Zr and La), all showing various enrichments in large ion lithophiles and light rare earth elements, and a depletion in high-field strength elements, suggestive of a destructive plate margin setting. The protoliths of the all samples might have formed mostly by the partial melting of an enriched source, possibly coupled with the fractional crystallization of plagioclase, apatite, and titaniferous magnetite ± olivine ± clinopyroxene ± amphibole in relation with subduction-related magmatism neighboring the Andean-type active margins of Gondwana. The group 2 samples could, however, be generated by a relatively lower degree of the partial melting of an inhomogeneous source with a preponderance of a high-level, fractional crystallization process in comparison to group 1. The protoliths of the samples were metamorphosed up to amphibolite facies conditions, which destroys original igneous texture and mineral assemblages. Geothermobarometric calculations show that the metamorphic rocks are finally equilibrated between 540 and 610°C and ,5 kbars, following a clockwise P-T-t path. [source]

    Rare Earth Element and Trace Element Features of Gold-bearing Pyrite in the Jinshan Gold Deposit, Jiangxi Province

    ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2010
    Guangzhou MAO
    Abstract: Jinshan gold deposit is located in northeastern Jiangxi, South China, which is related to the ductile shear zone. It has a gold reserve of more than 200 tons, with 80% of gold occurring in pyrite. The ,REE of gold-bearing pyrite is as higher as 171.664 ppm on average, with relatively higher light rare earth elements (LREE; 159.556 ppm) and lower HREE (12.108 ppm). The ,LREE/,HREE ratio is 12.612 and (La/Yb)N is 11.765. These indicate that pyrite is rich in LREE. The (La/Sm)N ratio is 3.758 and that of (Gd/Yb)N is 1.695. These are obvious LREE fractionations. The rare earth element (REE) distribution patterns show obvious Eu anomaly with average ,Eu values of 0.664, and ,Ce anomalies of 1.044. REE characteristics are similar to those of wall rocks (regional metamorphic rocks), but different from those of the Dexing granodiorite porphyry and Damaoshan biotite granite. These features indicate that the ore-forming materials in the Jinshan gold deposit derived from the wall rocks, and the ore-forming fluids derived from metamorphic water. The Co/Ni ratio (average value 0.38) of pyrite suggests that the Jinshan gold deposit formed under a medium,low temperature. It is inferred from the values of high-field strength elements, LREE, Hf/Sm, Nb/La, and Th/La of the pyrite that the ore-forming fluids of the Jinshan gold deposit derived from metamorphic water with Cl>F. [source]

    Permian High Ba-Sr Granitoids: Geochemistry, Age and Tectonic Implications of Erlangshan Pluton, Urad Zhongqi, Inner Mongolia

    ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2009
    Hongling LUO
    Abstract: Erlangshan Pluton from Urad Zhongqi, central Inner Mongolia, is located in the middle segment of the northern margin of the North China Plate. The rocks consist mainly of diorites with gneissic structure. Petrochemical characteristics reveal that the diorites belong to metaluminous, high-potassium calc-alkaline series, with chemical signatures of I-type granites. They are characterized by low SiO2 contents (56.63%,58.53%) and A/CNK (0.90,0.96), high Al2O3 contents (17.30%,17.96%) and Na2O/K2O ratios (1.20,1.70), enrichment in large ion lithophile elements (LILE, e.g., Ba=556,915 ppm, Sr=463,595 ppm), and relative depletion in high field strength elements (HFSE, e.g., Nb, Ta, Ti) in primitive mantle-normalized spidergram, and right-declined rare earth element patterns with slightly negative Eu anomalies (,Eu=0.72,0.90). They have Sr/Y ratios (20,25) evidently less than Kebu Pluton (49,75) to its east. Sensitive high resolution ion micro-probe U-Pb zircon dating of the diorites has yielded an intrusive age of 270±8 Ma. This leads us to conclude that Erlangshan diorites were formed by mixing between the middle or lower crustal-derived magma and minor mantle-derived mafic magma, followed by fractional crystallization, which was trigged by crustal extension and fault activity in post-collisional setting. [source]

    Chronology and Geochemistry of Mesozoic Volcanic Rocks in the Linjiang Area, Jilin Province and their Tectonic Implications

    ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2009
    Yang YU
    Abstract: Zircon U-Pb ages and geochemical analytical results are presented for the volcanic rocks of the Naozhigou, Ergulazi, and Sidaogou Formations in the Linjiang area, southeastern Jilin Province to constrain the nature of magma source and their tectonic settings. The Naozhigou Formation is composed mainly of andesite and rhyolite and its weighted mean 206Pb/238U age for 13 zircon grains is 222±1 Ma. The Ergulazi Formation consists of basaltic andesite, basaltic trachyandesite, and andesite, and six grains give a weighted mean 206Pb/Z38U age of 131±4 Ma. The Sidaogou Formation consists mainly of trachyandesite and rhyolite, and six zircon grains yield a weighted mean 206Pb/238U age of 113±4 Ma. The volcanic rocks have SiO2= 60.24%,77.46%, MgO = 0.36%,1.29% (Mg#= 0.32,0.40) for the Naozhigou Formation, SiO2= 51.60%,59.32%, MgO = 3.70%,5.54% (Mg#= 0.50,0.60) for the Ergulazi Formation, and SiO2= 58.28%,76.32%, MgO = 0.07%,1.20% (Mg#= 0.14,0.46) for the Sidaogou Formation. The trace element analytical results indicate that these volcanic rocks are characterized by enrichment in light rare earth elements (LREEs) and large ion lithophile elements (LILEs), relative depletion in heavy rare earth elements (HREEs) and high field strength elements (HFSEs, Nb, Ta, and Ti), and negative Eu anomalies. Compared with the primitive mantle, the Mesozoic volcanic rocks in the Linjiang area have relatively high initial 87Sr/86Sr ratios (0.7053,0.7083) and low ,Nd(t) values (,8.38 to ,2.43), and display an EMU trend. The late Triassic magma for the Naozhigou Formation could be derived from partial melting of a newly accretional crust with the minor involvement of the North China Craton basement and formed under an extensional environment after the collision of the Yangtze Craton and the North China Craton. The Early Cretaceous volcanic rocks for the Ergulazi and Sidaogou Formations could be formed under the tectonic setting of an active continental margin related to the westward subduction of the Izanagi plate. [source]