共查询到20条相似文献，搜索用时 281 毫秒
1.
2.
L. Fuks I. Herdzik-Koniecko L. Maskalchuk T. Leontieva 《International Journal of Environmental Science and Technology》2018,15(10):2047-2058
Results of sorption of caesium(I), strontium(II), europium(III) and americium(III) ions on the aluminosilicates separated from the clay-salt slimes (CSS) depending on the contact time, pH, initial metal concentration are presented. CSS 1A and CSS 1B sorbents appear to be sufficiently chemically and radiation stable for practical application in treatment of the radioactive wastewaters. 相似文献
3.
The aim of this paper was to analyse water dynamics in the soil from tensiometer data in two different plots, one with bare
soil and another with geotextiles and grass, correlating the information generated in the study concerning biotextile efficiency
in soil moisture maintenance, which is essential to vegetation development and to the recovery from and control of erosion.
Tensiometers were installed on the bare soil and grass plots at different depths (15, 30, 80 and 120 cm), and the respective
readings were taken with a digital tensimeter. Water dynamics inside the soil can be demonstrated by matric potential data
from pressure differences. A large difference between the bare soil and grass plots was demonstrated by matric potential medium
values at depths of 15, 30, 80 and 120 cm during monitoring. 相似文献
4.
The geothermal flow which emerges by convection at the springs in Aragón is evaluated, and compared with the theoretical heat flow which permeates the surface of the region by conduction. The geological materials through which the convection takes place are defined (geothermal formations), and the areas where thermal convection appears most intensely are related.
Resumen En el presente trabajo se evalúa el flujo geotérmico que emerge por convección en los principales manantiales de aguas termales de Aragón (España), comparándolo con el flujo geotérmico que penetra en la corteza terrestre por conducción. Se definen las formaciones geotérmicas y se estudian las áreas en las que se concentra de forma preferente ese flujo termal por convección.
Résumé Le flux géothermique qui émerge par convection à la source Aragon est évalué, et comparé avec le flux de chaleur théorique par conduction. Le matériel géologique dans lequel la convection prend place est défnit (formations géothermiques) et les zones qui manifestent les plus importantes convections thermiques sont relatés.相似文献
5.
《Geochimica et cosmochimica acta》1999,63(19-20):3205-3215
Sorption processes typically control trace metal concentrations in aquatic systems. To illustrate the impact of various types of surface sites on metal ion sorption behavior, Co(II) and Sr(II) sorption by several clay minerals under a range pH and background electrolyte conditions was studied. X-ray absorption spectroscopy (XAS) was used to characterize the surface complexes formed to explain the basis for the sorption trends. At low pH, Co(II) could be displaced from the surface by increasing the Na ion concentration. XAS analysis of these samples showed that sorbed Co(II) retained the coordination structure of aqueous phase Co(II), suggesting the formation of weakly associated, outer-sphere, mononuclear Co complexes at permanent charge sites. At high pH, sorbed Co could not be displaced by increasing the Na ion concentration. The XAS analyses of these samples indicated the formation of Co coprecipitates. The results of the Sr(II) sorption experiments suggested weaker bonding between sorbed Sr and the solid surfaces, regardless of solution conditions and adsorbent. XAS analysis of Sr sorption samples revealed the formation of mononuclear, outer-sphere complexes of Sr at clay–water interfaces, similar to the outer-sphere Co sorption samples observed only at low pH. 相似文献
6.
Heidi Wehrmann Kaj Hoernle Guillaume Jacques Dieter Garbe-Schönberg Kai Schumann Julia Mahlke Luis E. Lara 《International Journal of Earth Sciences》2014,103(7):1945-1962
Here we present the first systematic investigation of volatile geochemistry along the Southern Volcanic Zone (SVZ) of Chile. Holocene olivine-hosted melt inclusions in the most mafic tephras sampled from 16 volcanoes along the volcanic front of the SVZ between 33°S and 43°S were analysed for pre-eruptive sulphur, chlorine, and major element contents. These results are combined with trace element compositions of the host whole rocks. The highest fractionation-corrected gas contents occur in the least-degassed melt inclusions from small monogenetic cones of Los Hornitos, Cabeza de Vaca, and Apagado from both the transitional and the southern-central SVZ, reaching ~3,000 μg/g S and 1,400 μg/g Cl, while the lowest abundances of ~1,100 μg/g S and ~600 μg/g Cl were found in the central SVZ at Volcán Lonquimay, Volcán Llaima, and Volcán Villarrica. Chlorine co-varies with trace element indicators for the degree of melting and/or source enrichment, such that the lowest Cl contents are found in high-degree melts from the most depleted mantle sources. The size of the volcanic edifices correlates inversely with Cl abundances in the melt. This could reflect more extensive degassing during ascent through the complex magma plumbing systems beneath the stratovolcanoes or greater dilution during larger degrees of melting of more depleted sources, or a combination of these factors. Compared to other subduction zones, the SVZ melt inclusions exhibit Cl and S abundances in the same range as most of those from the Central American and those from the Marianas arcs. 相似文献
7.
《中国地质大学学报(英文版)》2000,(2)
The petrography,the geochemistry and the burial his-tory all constrain the origin and m odification history ofdolomites in an ancient periplatform carbonate slope deposit,the Machari Form ation (late Middle to early L ate Cambrian) ,Korea.The formation is mainly composed of rhythmic bed-ding,lam inated to bedded lime mudstone alternating withargillaceous lime mudstone.The rhythm ic bedding is a prod-uct of the deposition of offshore periplatform ooze andhemipelagic clay on a periplatform slo… 相似文献
8.
Pyroclastic materials dispersed in recent volcanic eruptions in Northern Patagonia were analysed in order to characterize the volcanic provenance by the geochemical fingerprint. The volcanic products studied were dispersed by eruptions of volcanoes Calbuco in 1961, Chaitén in 2008, and Cordón Caulle Volcanic Complex (CCVC) in 1960 and 2011. The geochemical characterization was based on the determination of 35 major and trace elements by Instrumental Neutron Activation Analysis, including geochemical tracer such as Rare Earth Elements (REE). The study of the pyroclastic products also included the morphological analysis by petrographic and scanning electron microscopy, and the mineralogical characterization by X-ray diffraction.Geochemical tracers determined in the glass fraction of the dispersed pyroclastic materials allowed a clear discrimination of the three volcanoes that gave origin to the tephras, the three of them with different evolution degree. Tephras from 1960 and 2011 CCVC eruptions showed the same geochemical signature. The geochemical parameters providing the differential characterization are the normalized REE and multi-element patterns, the Eu anomaly, the heavy to light and medium to light REE normalized ratios, and the Cs, Sc, Rb, Ta and Th concentrations. The bulk glassy fraction showed the same composition for each volcanic eruption in samples collected even in distant sites (from 100 to 220 km in Chaitén, 2008, and from 80 to 650 km in CCVC 2011), attesting to be the most reliable material for correlation purposes.According to the mineralogy, cristobalite was found in volcano Chaitén tephra as an indicator of such origin. Arsenic, an element of environmental interest, exhibited concentrations ranging from 6 to 16 μg g−1, with the highest values corresponding to Puyehue–Cordón Caulle and Chaitén products. 相似文献
9.
Tengattini Alessandro Nguyen Giang D. Viggiani Gioacchino Einav Itai 《Acta Geotechnica》2023,18(1):57-75
Acta Geotechnica - This paper presents an experimental and analytical/numerical study of the mechanics of cemented granular materials (CGMs). This study incorporates both in situ X-ray tomography... 相似文献
10.
11.
12.
《岩矿测试》2007,(1)
No.1 Chemical separation and isotopic variations of Cu and Zn from five geological reference materials Chapman J.B., Mason T.F.D., Weiss D.J., Coles B.J., Wilkinson J.J.(5 -16)…………………………………………………………………………Trace element analysis of fused whole-rock glasses by laser ablation-ICP-MS and PIXEKurosawa M., Shima K., Ishii S., Sasa K.(17 -30)……………………………………………………………………………………………………………………Determination of Ti, K, Sm and … 相似文献
13.
14.
15.
16.
《地学前缘(英文版)》2022,13(2):101138
In paleogeographic reconstructions of the Columbia and Rodinia Supercontinents, the position of the Greater India landmass is ambiguous. This, coupled with a limited understanding of the tectonic evolution of the mobile belts along which the mosaic of crustal domains in India accreted, impedes precise correlation among the dispersed crustal fragments in supercontinent reconstructions. Using structural, metamorphic phase equilibria, chronological and geochemical investigations, this study aims to reconstruct the tectonic evolution of the Chottanagpur Gneiss Complex (CGC) as a distinct crustal block at the eastern end of the Greater Indian Proterozoic Fold Belt (GIPFOB) along which the North India Block (NIB) and the South India Block (SIB) accreted. The study focuses on two issues, e.g. dating the Early Neoproterozoic (0.92 Ga) accretion of the CGC with the NIB contemporaneous with the assembly of Rodinia, and documenting the widespread (>24,000 km2) plutonism of 1.5–1.4 Ga weakly peraluminous, calc-alkalic to alkali-calcic and ferroan A-type granitoids (± garnet) devoid of mafic microgrannular enclaves and coeval mafic emplacements in the crustal block. These dominantly within-plate granitoids arguably formed by asthenospheric upwelling induced partial melting of garnet-bearing anatectic quartzofeldspathic gneisses that dominate the Early Mesoproterozoic basement of the block. The major and trace element chemistry of the granitoids is similar to the 1.35–1.45 Ga A-type granitoids in Laurentia/Amazonia emplaced contemporaneous with the 1.5–1.3 Ga breakup of the Columbia Supercontinent.This study suggests the Chottanagpur Gneiss Complex occured as a fragmented crustal block following the breakup of the Columbia Supercontinent; the crustal block was subsequently integrated within India during the Early Neoproterozoic oblique accretion between the NIB and SIB contemporaneous with the Rodinia Supercontinent assembly. 相似文献
17.
Dawnika L. Blatter Ian S. E. Carmichael 《Contributions to Mineralogy and Petrology》1998,132(2):121-138
Approximately 150 km west of Mexico City in the central part of the Mexican Volcanic Belt (MVB) near Zitácuaro, Mexico, young
volcanism has produced shield volcanoes, large volume silicic deposits, and fault-related basalt and andesite lava flows and
cinder cones. This paper concerns a small cluster of Pleistocene andesite cones and flows which can be separated into two
distinct groups: high-magnesium andesites (>6% MgO, 57–59% SiO2), conveniently called basaltic andesites, with phenocrysts of orthopyroxene and augite, or augite and olivine; and andesites
(60–62% SiO2, <4.6% MgO), which have phenocrysts of orthopyroxene and augite, and ghosts of relict hornblende. Remarkably, plagioclase
phenocrysts are absent, and evenly distributed but sparse (0.5–3.5%) quartz xenocrysts are present in all the lavas. In order
to establish the conditions under which early crystallizing plagioclase is suppressed in these lavas, water saturated experiments
up to 3 kbars were performed on one of the basaltic andesites. The conditions required to reproduce the phenocryst assemblages
(either olivine + augite or opx + augite) are temperatures in excess of 1000 °C, with water saturated liquids (>3 wt%) at
pressures of about 1 kbar. Compared to basaltic andesites of western Mexico, the Zitácuaro basaltic andesites have ∼2 wt%
lower Al2O3 concentrations, which causes plagioclase to precipitate at significantly lower temperatures, and it therefore follows the
crystallization sequence: olivine, augite, and orthopyroxene. Based on ubiquitous quartz xenocrysts, with glassy rhyolitic
inclusions, a reasonable conclusion is that substantial mixing of a quartz-bearing rhyolitic magma with a parental basaltic
andesite has occurred at low pressure (shallow depth), and this would account for the low Al2O3 concentrations in the Zitácuaro basaltic andesites. Whatever the mechanism of incorporation, the quartz xenocrysts are evidence
of contamination of basaltic magma with more siliceous material, thus making it difficult to use these magmas as indicators
of mantle melting processes.
Received: 29 July 1997 / Accepted: 29 January 1998 相似文献
18.
19.
Summary Childrenite and crandallite are described as two new phosphate members in the paragenesis of the Stari Trg mine which comprises vivianite, ludlamite and struvite. Crandallite crystals with very simple rhombohedral habit grow on rhombohedral carbonate and childrenite crystals. The crystal morphology of childrenite is very similar to that at described from other localities. Following forms were measured: {100}, {100}, {110}, {120}, {121}, {221} and {342}. The average chemical composition is Ch91 Eo9 (Ch-childrenite, Eo-eosphorite). Pseudo-orthorhombic unit cell dimensions were calculated: a = 10.390(4) A, b = 13.390(4) A and c = 6.920(2) A. Growth sectors and sector twins of childrenite are described.
With 4 Figures 相似文献
Childrenit und Crandallit aus der Stari Trg Grube (Trepa), Kosovo: Neue Daten
Zusammenfassung Childrenit und Crandallit werden als zwei neue Minerale der Phosphatgruppe beschrieben. Sie stammen aus der Stari Trg Grube in Paragenese mit Vivianit, Ludlamit und Struvit. Die Crandallit-Kristalle mit einfachem rhomboedrischen Habitus, wachsen rhomboedrischen Karbonat- und Childrenit-Kristallen auf. Die Kristallmorphologie von Childrenit ist, verglichen mit der aus anderen Lokalitäten, sehr einfach. Folgende Formen wurden gemessen: {100}, {010}, {110}, {120}, {121}, {221} und {342}. Die durchschnittliche chemische Zusammensetzung ist Ch(91Eo9(Ch-Childrenit, Eo Eosphorit). Eine Kalkulation der pseudo-orthorhombischen Elementarzelle ergab folgende Abmessungen: a = 10.390(4) A, b = 13.390(4) A and c = 6.920(2) A. Schließlich wird das Wachstum and die Zwillingsbildung von Childrenit beschrieben.
With 4 Figures 相似文献
20.