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1.
Determination of cadmium(II), copper(II), manganese(II) and nickel(II) species in Antarctic seawater with complexing resins 总被引：1，自引：0，他引：1
Raffaela Biesuz Giancarla Alberti Girolamo D'Agostino Emanuele Magi Maria Pesavento 《Marine Chemistry》2006,101(3-4):180-189
The strong species of cadmium(II), copper(II), manganese(II) and nickel(II) in an Antarctic seawater sample are investigated by a method based on the sorption of metal ions on complexing resins. The resins compete with the ligands present in the sample to combine with the metal ions. Two resins with different adsorbing strengths were used. Very stable metal complexes were investigated with the strong sorbent Chelex 100 and weaker species with the less strong resin, Amberlite CG-50. Strong species were detected for three of the considered metal ions, but not for Mn(II). Cu(II) is completely linked to species with a side reaction coefficient as high as log αM(I) = 11.6 at pH = 7.3. The ligand concentration was found to be similar to that of the metal ion, and the conditional stability constant was around 1020 M− 1. In the considered sample, only a fraction of the metal ions Cd(II) and Ni(II) is bound to the strong ligands, with side reaction coefficients equal to log αM(I) = 5.5 and 6.5 at pH = 7.3 for Cd(II) and Ni(II), respectively. These findings were confirmed by the test with the weaker sorbent Amberlite CG-50. It can be calculated from the sorption equilibria that neither Mn(II) nor Ni(II) is adsorbed on Amberlite CG-50 under the considered conditions and, in fact, only a negligible fraction of Mn(II) and Ni(II) was adsorbed. A noticeable fraction of Cd(II) was adsorbed on Amberlite CG-50, meaning that cadmium(II) is partially linked to weak ligands, possibly chloride, while no copper(II) was adsorbed on this resin, confirming that copper(II) is only combined in strong species. These results are similar, but not identical, to those obtained for other seawater samples examined in previous investigations. 相似文献
2.
Tsunamis generated by landslides at the coast of conical islands: experimental benchmark dataset for mathematical model validation 总被引：1，自引：0，他引：1
A. Romano M. Di Risio G. Bellotti M. G. Molfetta L. Damiani P. De Girolamo 《Landslides》2016,13(6):1379-1393
This paper presents a new experimental campaign aimed at reproducing tsunamis generated by landslides at the flank of conical islands. In order to describe in high details the wave field around the island a special acquisition system, which consists of both fixed and movable wave gauges, has been employed. Indeed, each experiment has been repeated several times by changing the configuration of the movable gauges, then obtaining a single virtual experiment with high spatial resolution measurements. Fixed run-up gauges measure the waves at fixed locations to statistically quantify the repeatability of the experiments. Selected experimental results are illustrated within the paper that is mainly aimed at defining a benchmark dataset, available on request, for the development/calibration/validation of analytical and numerical models of tsunamis generated by landslides. 相似文献
3.
Summary Major, trace element and Sr-Nd-isotopic data on mafic volcanic rocks with shoshonitic affinity from the islands of Procida and Ventotene (Campanian Region, South Italy) are reported. Within-suite chemical and isotopic variations are interpreted in terms of open system differentiation processes held responsible for enrichment in a number of trace elements and for radiogenic Sr observed in both Procida and Ventotene volcanic sequences. Conversely, trace element contents and Sr-Nd-isotopic compositions of the least-evolved among the investigated samples are thought to reflect source region characteristics with only negligible crustal contamination of the primary magmas.The data support an origin from distinct source regions for the primary magmas. In the case of Ventotene, the source would have been asthenospheric and/or lithospheric mantle with features similar to transitional mid-ocean ridge basalts (T-MORB), modified by enriching agents made up mainly of subducted slab-released components coming from marly sediments (about 7%) similar to cherts from Tuscan Apennines plus a limestone contribution. In the case of Procida, the source would have been asthenospheric and/or lithospheric mantle with a slightly more enriched T-MORB-like feature with respect to Ventotene, modified by slab-derived enriching agents, likely represented by a small amount of sediments (about 2.5%) of oceanic nature (mostly terrigenous/pelagic). These differences are constrained by lower Zr/Nb, Y/Nb, Sc/Nb, V/Nb, LILE/HFSE, LREE/HFSE and87Sr/86Sr, higher Ba/La and143Nd/144Nd ratios, as well as by the lack of a detectable negative Eu anomaly, in the least-evolved volcanic rocks of Procida, with respect to those of Ventotene, which show conversely a significant negative Eu anomaly. Thus, a sharp heterogeneity exists in the mantle beneath the Campanian Region. It is thought to be the consequence of two different slabs which are in contact along the Volturno River Plain tectonic line: a continental slab, seismically inactive, descending beneath the Latium Region, and an oceanic slab, seismically active, descending beneath the Calabria, up to the Campanian Region.
With 9 Figures 相似文献
Résumé De nouvelles analyses géochimiques d'éléments majeurs et en traces ainsi que des rapports isotopiques du Sr et du Nd sont été obtenues sur des roches volcaniques mafiques à affinité shoshonitiques provenant des îles de Procida et Ventotene (Région Campanienne, Italie du Sud). Les variations géochimiques et isotopiques observées au sein des séries volcaniques de ces deux îles sont interprétées en terme de processus de différenciation en système ouvert, tenu pour responsable d'un enrichissement d'un certain nombre d'éléments en traces et de leur composition en Sr radiogénique. Cependant, les teneurs en éléments traces et les compositions isotopiques en Sr et Nd des échantillons les moins évolués parmi ceux étudiés reflètent les caractéristiques de leur source, avec une contamination crustale très négligeable des magmas primitifs.Ces données démontrent que des sources distinctes sont à l'origine des magmas primitifs. Pour Ventotene, cette source doit être un manteau asthénosphérique et/ou lithosphérique dont la signature est similaire à celle de basaltes transitionnels de dorsale océanique (T MORB), légèrement enrichie en éléments dérivants d'une croûte plongeant dans une subduction comme des sédiments mameux (pour environ 7%) analogues aux cherts des Appenins de Toscane et comportant un apport en calcaire. Dans le cas de Procida, cette source doit être un manteau asthénosphérique et/ou lithosphérique montrant une signature de type T-MORB légèrement plus enrichie qu' à Ventotene, également modifiée par un apport venant d'une croûte en subduction, probablement une faible quantité (environ 2.5%) de sédiments de nature océanique (principalement terrigène/pélagique). Ces différences sont attestées par des rapports Zr/Nb, Y/Nb, Sc/Nb, V/Nb, LILE/HFSE, LREE/HSFE and87Sr/86Sr plus bas et des rapports Ba/La et143Nd/144Nd plus harts, ainsi que par l'absence d'une anomalie en Eu dans les compositions des roches volcaniques les moins évoluées de Procida par rapport à celles de Ventotene, qui elles, au contraire, montrent une anomalie en Eu significative.Ainsi, une importante hétérogénéité du manteau existe sous la Campanie. Cette hétérogénéité doit être la conséquence de la nature différente des croûtes en subduction et qui sont en contact le long de la ligne tectonique de la plaine de la rivière Volturno: an Nord-Ouest, une croûte continentale, sismiquement inactive, plonge sous le Latium alors qu'au Sud-Est, une croûte océanique, sismiquement active, plonge sous la Calabre et jusque sous la Campanie.
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4.
Two basaltic fragments dredged from a volcanic seamount in the Sicilian continental slope of the Strait of Sicily show petrochemical features typical of within plate alkalibasaltic lavas and K/Ar age of about 10 m.y. The data represent the first volcanic evidence of Upper Miocene tensional tectonics in this sector of the African plate. 相似文献
5.
P. Di Girolamo 《Bulletin of Volcanology》1978,41(3):229-250
The volcanic rocks along the south-eastern and eastern Tyrrhenian border of Italy have been classified as converging plate margin magma types by using discriminant functions based on major element patterns. These rocks belong to calc-alkaline and shoshonitic associations (shoshonites, and predominant leucitic rocks) ranging in age from Upper Miocene to, mostly, Quaternary. According to the same method of classification, the remaining Italian volcanic rocks — alkali-sodic and subordinate tholeiitic basalts — around the Tyrrhenian border are found to be rocks of the tensional type of Mesozoic to prevailingly Quaternary age. The volcanic materials of the 650 km long SE and E Tyrrhenian border can be related to the convergence of the African-Adriatic and Tyrrhenian plates. 相似文献
6.
The aim of this paper is to illustrate the results of a preliminary study on aerial landslide-generated waves, which has been mainly intended to establish a method for analyzing water surface records. Some simple physical experiments, reproducing the Scott Russell's wave generator, were carried out in a small two-dimensional wave flume; the Wavelet Transform (WT) is applied to analyze wave measurements and it is shown that useful information can be obtained by means of this technique. The celerity of impulsively generated waves, reflection by an overflow structure and seiching phenomena of the flume are studied. A discussion of the results along with some remarks about ongoing research is also given. 相似文献
7.
Summary New data of mineral compositions, whole-rock major and trace element contents are presented for lava flows and dykes of Mt. Vulture volcano (southeastern Roman Magmatic Province). The dominant rock series ranges from basanite, through tephrite and foidite, to phonolite. Diopsidic to Fe-salitic (hedenbergitic) clinopyroxene is the major phenocryst phase, and shows a very strong Ti- and Al-enrichment trend (up to 5 wt% TiO2 and 12 wt% Al2O3). Phonolites have Fe-rich pyroxenes low in Ti and Al, as a consequence of fractionation of Ti-magnetite and/or melanite garnet.Feldspar ranges in composition from bytownite to Ba- and Sr-rich anorthoclase (up to 7 wt % BaO and 4 wt % SrO); the latter is present in the groundmass of mafic and intermediate rocks. Phonolites are characterized by anorthoclase and sanidine with Ba-rich cores, and with Ba-depleted rims.Subordinate melilite-bearing rocks are also present, and are characterized by melilite with a very large compositional variation, Ca-rich nepheline (up to 8 wt% CaO) and lack of feldspar and amphibole. Some of them also show calcite-rich ocellar structures, possibly due to liquid immiscibility. They have also major and trace element contents different from those of the feldspar-bearing rocks. This all indicates distinct parental magmas for feldspar-bearing and melilite-bearing rocks. These latter were likely generated by differentiation processes starting from olivine- and melilite-bearing ultramafic parental magmas.Mineral compositions and suitable phase diagrams indicate that the Melfi haüynophyre, which is the most MgO-poor melilite-bearing rock of Mt. Vulture, is close to a residual melt analogous to phonolite, but in petrogenetic systems with melilite and without feldspar.The high- to very high-titanium content of most of the ferromagnesian phases, despite a relatively low TiO2 of primitive Mt. Vulture rocks, is absent in other rocks of similar degree of evolution in the Roman Province. It resembles that found in anorogenic magmas and gives further indications for a within-plate signature in this particular volcanic complex.
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Der Mt. Vulture Vulkankomplex (Italien): hinweise für unterschiedliche Ausgangsmagmen und Residualschmelzen mit Melilith
Zusammenfassung Es werden neue Daten über Mineralzusammensetzungen sowie Haupt- und Spurenelemente des Gesamtgesteins für Lavaflüsse und Gänge des Mt. Vulture Vulkans (südöstliche Römische Magmatische Provinz) vorgestellt. Die auftretenden Gesteinsabfolgen reichen von Basaniten über Tephrite und Foidite zu Phonolithen. Diopsidischer bis Fe-salitischer (hedenbergitischer) Klinopyroxen stellt die hauptsächlichen Einsprenglinge und zeigt starke Ti- und Al-Anreicherungen (bis zu 5 Gew% TiO2 und 12 Gew% Al2O3). Phonolite weisen als Konsequenz der Fraktionierung von Ti-Magnetit und/oder Melanit-Granat Fe-reiche Pyroxene mit niedrigen Ti- und Al-Gehalten auf.Der Feldspat reicht in seiner Zusammensetzung von Bytownit zu Ba- und Si-reichem Anorthoklas (bis zu 7 Gew%/o BaO und 4 Gew% SrO), der letztgenannte findet sich in der Grundmasse mafischer und intermediärer Gesteine. Phonolithe werden durch das Auftreten von Anorthoklas und Sanidin mit Ba-angereicherten Kernen und Ba-abgereicherten Rändern charakterisiert.Untergeordnet treten auch Melilith-führende Gesteine auf. Sie sind durch Melilithe mit einer großen kompositionellen Variation, durch Ca-reichen Nephelin (bis 8Gew% CaO) und durch das Fehlen von Feldspat und Amphibol gekennzeichnet. Einige dieser Melilithe zeigen auch Calcitreiche ocellare Strukturen, die möglicherweise aufgrund der Nicht-Mischbarkeit der Schmelzen entstanden sind. Sie weisen auch Gehalte an Haupt- und Spurenelementen auf, die von jenen Feldspat-führender Gesteine abweichen. All dies zeigt verschiedene Ausgangs-Magmen für Feldspat-führende und Melilith-führende vulkanische Gesteinean. Die Melilithgesteine entstanden wahrscheinlich durch Differentiationsprozesse aus Olvin- und Melilith-führenden ultramafischen Magmen.Mineralzusammensetzung und die entsprechenden Phasendiagramme zeigen, daß der Melfi Haüynophyr, welcher das MgOärmste Melilith-führende Gestein des Mt. Vulture ist, nahe an einer Ausgangschmelze analog zu einem Phonolith liegt, allerdings in einem petrogenetischen System mit Melilith und ohne Feldspat.Der hohe bis sehr hohe Titan-Gehalt der meisten ferromagnesischen Phasen fehlt, trotz des niedrigen TiO2-Gehaltes primitiver Mte. Vulture Gesteine, in anderen Gesteinen ähnlicher Entwicklung in der Römischer Magmatischen Provinz. Dies ähnelt anorogenen alkalischen Magmen und ist ein weiterer Hinweis auf eine Intra-Platten Signatur für diesen besonderen vulkanischen Komplex.
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8.
Juan Bautista Belardi Gisela Cassiodoro Rafael Goi Michael D. Glascock Alejandro Súnico 《Geoarchaeology》2015,30(3):223-237
Hunter‐gatherer mobility and spheres of interaction are important characteristics worthy of investigation in Patagonian archaeology. One way to approach these is by studying the distribution of lithic archaeological materials. Siltstone (limolite) artifacts are found along the western strip of southwestern Patagonia, Argentina. Based on geomorphological studies and the high density of archaeological material, a source was located along the western margin of Cardiel Lake. Neutron activation analysis of samples from the source and archaeological sites in several neighboring basins allowed us to model its circulation. Siltstone's archaeological distribution indicates that its regional circulation had a southerly direction dating from the early Holocene. This southern vector shows an important difference when compared to the distribution of obsidian from Pampa del Asador, which has a broader circulation pattern. This could be related to a greater availability of high‐quality lithic materials north of the siltstone source. This work also contributes to the construction of a lithic source database for southern Patagonia. 相似文献
9.
L. Beccaluva M. Coltorti P. Di Girolamo L. Melluso L. Milani V. Morra F. Siena 《Mineralogy and Petrology》2002,74(2-4):277-297
Summary The Late Pleistocene Mt. Vulture strato-volcano developed at the intersection of NE-SW and NW-SE lithospheric fault systems,
on the easternmost border of the Apennine compressional front overthrust onto the Apulian foreland. The initial phase of the
volcanic activity is represented by pyroclastic deposits, including lava blocks, and subordinate eccentric domes, mostly phonolitic
in composition. The later stages of activity formed the bulk of the strato-volcano (pyroclastic products and subordinate lavas),
mostly tephritic in composition, with minor intercalations of basanite, mela-foidite and melilitite lavas and dikes.
Variations in rock and mineral composition suggest that the volumetrically predominant basanite-tephrite (foidite)-phonotephrite-phonolite
series can be accounted for by fractional crystallization processes starting from basanitic parental magmas, in agreement
with the remarkably constant 87Sr/86Sr isotopes (0.70586–0.70581). Mass-balance calculations indicate that the variably differentiated magmas may have been produced
by removal of wehrlite, clinopyroxenite and syenite cumulates, some of which are occasionally found as cognate xenoliths in
the volcanics. Fractionation processes probably developed in multiple-zoned magma chambers, at depths of 3–5 km, corresponding
to the tectonic discontinuity between the allochthonous Apennine formations and the underlying Apulian platform. Highly differentiated
phonolitic magmas capping the magma chambers and their conduits thus appear to have fed the initial volcanic activity, whereas
dominantly tephritic products were erupted in later stages.
The least evolved mafic magmas, namely basanites, mela-foidites and melilitites, are characterized by diverse Na/K ratios
and critical SiO2-undersaturation, which indicate their derivation as independent melts generated from distinct, heterogeneously enriched mantle
sources and by variable partial melting degrees.
Primitive mantle-normalized incompatible element patterns of Vulture mafic lavas invariably share analogies with both orogenic
subduction-related magmas (high Low Field Strength Elements/High Field Strength Elements ratios, K, Rb and Th contents and
marked Ti and Nb negative anomalies) and alkaline lavas from within-plate and rift settings (high Light Rare Earth Elements,
P, Zr, Nb and Na). These geochemical features may be accounted for by magma generation from deep lithospheric mantle sources,
enriched in Na-alkali silicate/carbonatite anorogenic components, subsequently affected by orogenic subduction-related K-metasomatism,
analogous to that which modified magma sources of the Roman Magmatic Province along the internal Apennine Chain.
Received April 12, 2000; revised version accepted June 7, 2001 相似文献
10.