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Distribution, Morphology, and Chemical Composition of Fe-Mn Nodules in Albeluvisols of the Carpathian Foothills, Poland

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Pedosphere 2013年第4期23卷 445-454页

作者： W.SZYMANSKI M.SKIBA Department of Pedology and Soil Geography Institute of Geography and Spatial Management Jagiellonian University Department of mineralogy Petrology and Geochemistry Institute of Geological Sciences Jagiellonian University

Iron and manganese oxides are common components of soils. They frequently occur in nodules constituting important soil sorbents and play a crucial role in a number of chemical reactions in the soil environment. In addition, the oxides are very sensitive to environmental changes (moisture, pH, Eh) constituting important indicators of soil-forming processes and water movement in the landscape. The objectives of the study were: i) to examine the distribution and size of Fe-Mn nodules in Albeluvisols containing a fragipan horizon; ii) to determine the morphology and chemical composition of the nodules, and iii) to estimate the effect of the fragipan horizon on water movement within the soil profile. An investigation was carried out on five soil profiles containing a fragipan horizon and classified as Fragic Albeluvisols within the Carpathian Foothills in Poland. In the Albeluvisols studied, the maximum concentration of Fe-Mn nodules occurred in the horizon lying directly on the fragipan horizon. This suggests that the pan acts as a natural barrier restricting water infiltration and leads to the seasonal development of a perched water table promoting redox processes. The most common are coarse (1-0.5 mm) and medium (0.5-0.25 mm) irregular Fe-Mn nodules showing a gradual boundary and undifferentiated internal fabric. Eluvial horizons contained also larger amounts of round and dense nodules with a sharp boundary, suggesting frequent oxidation and reduction. The fragipan horizon contained mainly irregular and soft nodules, suggesting longer saturation with water during the year. Concentrations of trace elements (Cu, Zn) and P were higher within Fe-Mn nodules than in the surrounding soil materials, showing that iron and manganese oxides adsorbed and immobilised these elements.

关键词： fragipan horizon iron oxides manganese oxides perched water table redox processes

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Gneiss-Water Interaction and Water Evolution During the Early Stages of Dissolution Experiments at Room Temperature

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Chinese Journal Of Geochemistry 2003年第4期22卷 302-312页

作者：朱义年 Ingrid Stober Kurt Bucher Dept. of Resource and Environmental Engineering Guilin Institute of Technology Geological Survey Baden-Württemberg institute for mineralogy Petrology and Geochemistry University of Freiburg

Gneiss\|distilled water interaction at room temperature was investigated with batch\|reactors to study water\|rock reaction and geochemical evolution of the aqueous phase with time. The ion concentrations in water were controlled not only by the dissolution of primary minerals, but also by the precipitation of secondary minerals. The decreasing fraction sizes of gneiss could favor dissolution and precipitation simultaneously. Ca\+\{2+\} and K\++ were the major cations, and HCO\+-\-3 was the major anion in water. All the ions except Ca\+\{2+\} increased in concentration with time. The Ca\+\{2+\} release from the rock to the aqueous phase was initially much faster than the release of K\++, Na\++ and Mg\+\{2+\}. But after about 5-24 hours, the Ca\+\{2+\} concentrations in water decreased very slowly with time and became relatively stable. During the experiment, the water varied from the Ca\|(K)\|HCO\-3\|type water to the K\|Ca\|HCO\-3\|type water, and then to the K\|(Ca,Na)\|HCO\-3\|type water. The water\|gneiss interaction was dominated by the dissolution of K\|feldspar in the solution. The remaining secondary minerals were mainly kaolinite, illite and K(Mg)\|mica.

关键词： gneLss water interaction water evolufion

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Alkali control of high-grade metamorphism and granitization

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Geoscience Frontiers 2014年第5期5卷 711-727页

作者： Oleg G.Safonov Leonid Y.Aranovich institute of Experimental mineralogy RAS ChernogolovkaMoscow RegionRussia Department of petrology Moscow State UniversityMoscowRussia Department of Geology.University of Johannesburg Johannesburg.South Africa institute of Geology of Ore Deposits PetrographyMineralogy and Geochemistry

We review petrologic observations of reaction textures from high-grade rocks that suggest the passage of fluids with variable alkali activities. Development of these reaction textures is accompanied by regular compositional variations in plagioclase, pyroxenes, biotite, amphibole and garnet. The textures are interpreted in terms of exchange and net-transfer reactions controlled by the K and Na activities in the fluids. On the regional scale, these reactions operate in granitized, charnockitized, syenitized etc. shear zones within high-grade complexes. Thermodynamic calculations in simple chemical systems show that changes in mineral assemblages, including the transition from the hydrous to the anhydrous ones, may occur at constant pressure and temperature due only to variations in the H2O and the alkali activities. A simple procedure for estimating the activity of the two major alkali oxides, K2O and Na2O, is imple- mented in the TWQ software. Examples of calculations are presented for well-documented dehydration zones from South Africa, southern India, and Sri Lanka. The calculations have revealed two end-member regimes of alkalis during specific metamorphic processes： rock buffered, which is characteristic for the precursor rocks containing two feldspars, and fluid-buffered for the precursor rocks without K-feldspar. The observed reaction textures and the results of thermodynamic modeling are compared with the results of available experimental studies on the interaction of the alkali chloride and carbonate-bearing fluids with metamorphic rocks at mid-crustal conditions. The experiments show the complex effect of alkali activities in the fluid phase on the mineral assemblages. Both thermodynamic calculations and experiments closely reproduce paragenetic relations theoretically predicted by D.S. Korzhinskii in the 1940s.

关键词： High-grade metamorphismAlkali activityFluidsReaction texturesFluid-mineral reactionsThermodynamic modeling

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Soil Organic Matter Characterization Using S3 and S4 Signals from Rock-Eval Pyrolysis

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Pedosphere 2014年第5期24卷 563-574页

作者： M.HETNYI T.NYILAS Department of mineralogy Geochemistry and Petrology University of Szeged P.O.Box 651 H-6701 Szeged (Hungary)

Variations in the abundance of soil organic matter(SOM) constituents with different stability have a major impact on important environmental processes, e.g., carbon dioxide(CO2) fluxes between the soil and the atmosphere. Recently, besides the bulk Rock-Eval(RE) data, the mathematical deconvolution of the signals derived from hydrocarbon-like compounds released by thermal cracking of SOM during RE pyrolysis has been increasingly used to estimate the relative contribution of the major SOM classes differing in origin and preservation. This study applied the mathematical deconvolution of the S3 and S4 signals of carbon monoxide(CO) and CO2, produced both by the pyrolysis of the oxygen-containing moieties and by the oxidation of the residual highly resistant organic matter, to characterize the stability of these components. Our results suggested that the stability of the oxygen-containing moieties was controlled by the precursor material and was strongly affected by the land use and the presence of humic substances in the surface horizon of some main soil types in Hungary. In consistence with the bulk RE data, results of the mathematical deconvolution also proved to be diagnostic markers for discriminating the aquatic or terrigenous plants as the main sources of SOM. The mathematical deconvolution of S4 signals derived from the highly resistant SOM fraction allowed us to quantify the contribution of constituents with different stability. Furthermore, the results of this study displayed that the stability of this highly abundant SOM fraction in the surface soil samples depended on source biomass and intensity of leaching.

关键词： biomass leaching mathematical deconvolution oxygen-containing moieties SOM sources SOM stability

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Survived and disappeared intra-oceanic arcs of the Paleo-Asian Ocean: evidence from Kazakhstan

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National Science Review 2023年第2期10卷 49-68页

作者： Inna Safonova Alina Perfilova LabEPOM Novosibirsk State University Igneous petrology Lab Sobolev Institute of Geology and Mineralogy 3. Paleovolcanism and Geodynamics LabZavaritskiy Institute of Geology and Geochemistry Faculty of Geosciences and Environmental Engineering South-West Jiaotong University

This paper reviews published and presents new data on U-Pb detrital zircon ages,and petrographic,geochemical and isotope(Sm-Nd,Lu-Hf) compositions obtained from greywacke sandstones of Kazakhstan in order to reconstruct fossil intra-oceanic arcs that once existed at Pacific-type convergent margins of the Paleo-Asian Ocean(PAO) in Paleozoic *** focus on orogenic belts of central Kazakhstan(Itmurundy and Tekturmas) and eastern Kazakhstan(Zharma and Char) in the western Central Asian Orogenic *** orogenic belts host accretionary complexes with greywacke sandstones of early Paleozoic(central Kazakhstan) and middle-late Paleozoic(eastern Kazakhstan) ***,we evaluate general perspectives for studying sandstones to reconstruct survived and disappeared magmatic arcs,taking into account episodes of subduction *** we discuss the analytical data from sandstones to make conclusions about the ages and formation settings of their igneous protoliths and define maximum deposition ***,we discuss the role of serpentinite melanges in tectonic *** argue that sandstones hosted by accretionary complexes are typically greywackes deposited close to their igneous sources and buried *** provenances of the studied greywacke sandstones of central and eastern Kazakhstan were dominated by mafic to andesitic igneous protoliths derived from juvenile mantle *** igneous rocks in the provenances were emplaced in an intra-oceanic arc *** sandstones were deposited in fore-arc/trench basins or,to a lesser degree,in back-arc *** data from both sandstones and serpentinite melanges reconstruct middle-late-Cambrian,Ordovician,late-D evonian and Carboniferous arcs of the western *** middle-late Cambrian arcs were fully destroyed by subduction erosion,whereas the Ordovician and Carboniferous arcs *** late-D evonian arcs were also eroded,but *** the early and late Paleozoic active margins of the PAO were chara

关键词： Central Asian Orogenic belt Paleo-Asian Ocean Paleozoic subduction erosion greywacke sandstones serpentinite mélange

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Interaction of Mantle Rocks with Crustal Fluids: Sagvandites of the Scandinavian Caledonides

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Journal of Earth Science 2019年第6期30卷 1084-1094页

作者： Kurt Bucher Ingrid Stober mineralogy and petrology Institute of Earth and Environmental SciencesUniversity of Freiburg79104 FreiburgGermany College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266510China

Sagvandite is an enstatite+magnesite rock formed from dunite or harzburgite bodies occurring as tectonically emplaced fragments from the upper mantle in many orogenic belts by interaction with CO2-bearing crustal fluids at upper amphibolite facies P-T *** bodies occur widespread in distinct nappes in the Scandinavian Caledonides in *** to all of the many sagvandite outcrops is their general structure of radial bundles of very coarse cm-sized enstatite crystals and interstitial *** some strongly resorbed primary olivine is preserved,in addition to minor accessory Cr-spinel and *** dunite to sagvandite conversion is governed by three metasomatic reactions:(1)carbonatization of peridotite by CO2-bearing fluids;(2)interaction with external fluids containing dissolved silica;(3)loss of Mg by dissolution of forsterite in NaCl-rich deep *** progressξoverall of all three reactions in proportions that conserve the volume of the original dunite can explain the observed structure and mode of *** relationship among the progressξof the three reactions suggests that loss of Mg by the ultramafic rock is the dominating process in the iso-volume conversion of dunite to sagvandite.

关键词： sagvandite peridotite fluid-rock interaction metasomatism CO2-sequestration

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Sanidine-olivine-diopside Association in a Metasomatized Garnet Lherzolite Xenolith from Southeastern China

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Chinese Journal Of Geochemistry 1992年第1期11卷 55-69页

作者：曹荣龙朱寿华 K.AOKI H.FUJIMAKI institute of Geochemistry Academia SinicaGuangzhou BranchGuangzhou510640 institute of mineralogy Petrologyand Economic GeologyTohoku UniversitySendaiJapan

A garnet lherzolite xenolith hosted in olivine nephelinite from Xilong,Zhejiang Province ,southeastern China, shows clear evidence of modal metasomatism involving a special sanidine-olivine-diopside(SOD) association which was produced by replacement of primary *** fluid responsible for the measomatism was a silica-undersaturated vapour,rich in K,Ba,Sr and *** is suggested that the SOD assemblage is the product of metasomatism of a depleted lherzolite precursor,and formed in the upper mantle prior to entrainment and eruption.

关键词：透长石橄榄石透辉石交代变质作用石榴石铬尖晶石捕虏体中国

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Metasomatic Stages and Scapolitization Effects on Chemical Composition of Pasveh Pluton,NW Iran

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Journal of Earth Science 2011年第5期22卷 619-631页

作者： S A Mazhari S Amini J Ghalamghash F Bea Department of Geology Payame Noor University Department of Geology Tarbiat Moallem University Geological Survey of Iran Department of mineralogy and petrology Fuentenueva CampusUniversity of Granada

Pasveh gabbros are mafic component of a plutonic complex in the northwest Sanandaj- Sirjan Zone. These cumulative rocks are composed of plagioclase and calcic clinopyroxene （Cpx）, which yield unusually high CaO （〉19 wt.%） in whole-rock chemistry. Petrographical and geochemical data suggest that Pasveh gabbros can be divided into two groups： free scapolite and scapolite-bearing gabbros. The second group has higher Na20, K20, and P205 relative to free scapolite ones and is enriched in LIL （large ion lithophile） and HFS （high field strength） elements. Two stages of metasomatism affected the primary composition of mafic rocks. Firstly, high temperature reaction caused to invert primary high Ti clinopyroxene to low Ti cUnopyroxene＋high Ti amphibole. This reaction was extensive and included all gabbroic samples. Hydrothermal fluids involved in this process can be derived from dehydration reactions of country rocks or from other magmas incorporated in the formation of Pasveh complex pluton. The second metasomatic stage relates to scapolitization of limited parts of gabbroic rocks. An external saline fluid, which is composed of major NaCI and minor KCI and P205 components, impacted locally on Pasveh gabbros and formed the second metasomatic stage. Possible sources of Na and Cl are primary evaporites or brines, which were present in the host sediments of the gabbros. The carbonate-free nature of these hydrothermal fluids suggests that hydrothermal fluids responsible for the formation of scapolite in Pasveh gabbros are derived from marine evaporitic parentage.

关键词： Iran Sanandaj-Sirjan Zone Pasveh pluton gabbro metasomatism high Ti Cpx low Ti Cpx amphibole scapolite.

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Mineral Reaction and Oxygen Isotope Equilibrium——An Experimental Study on the Calcite-Forsterite System

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Chinese Science Bulletin 1994年第16期39卷 1382-1385页

作者：郑永飞 P. Metz M. Satir Department of Earth and Space Sciences University of Science and Technology of China Hefei 230026 PRC institute for mineralogy Petrology and Geochemistry University of Tubingen Wilhelmstrasse 56D-72074 Tubingen Germany

There are few mineral reaction experiments dealing with the stable isotope fractionation factors between the reaction products. The only known example is to determine oxygen isotope fractionations between quartz and magnetite at 600 and 800℃ by oxidizing fayalite to form quartz and magnetite. This experimental result has been confirmed by the experiments of isotope exchange reaction. In this note, we report the results of an investigation of oxygen isotope fractionation between calcite

关键词： mineral reaction equilibrium fractionation oxygen isotopes calcite forsterite.

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Platinum-group Element Geochemistry of Magnetite from Porphyry-Cu-Mo Deposits and their Host Rocks(Siberia,Russia)

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Acta Geologica Sinica(English Edition) 2012年第1期86卷 106-117页

作者： Anita BERZINA institute of Geology and mineralogy Novosibirsk630090Russia

The concentrations of platinum-group elements （PGE） have been analyzed in primary magmatic magnetite samples from the Zhireken, Shakhtama and Aksug porphyry Cu-Mo deposits （Siberia, Russia） by laser ablation-inductively coupled plasma mass spectrometry to determine the range of PGE contents in magnetites and to check whether magnetite from two main rock suites （barren plutonic suite and mineralized porphyry suite） has distinct PGE composition. The results presented here indicate that magnetites are enriched in PGE relative to whole-rocks. Comparison of ore-related porphyry and barren plutonic suites shows that magnetite exhibit relatively similar PGE distribution patterns in both suites. Variations in Rh and Ru contents were controlled by the oxygen fugacity during magma crystallization.

关键词： magnetite platinum-group elements porphyry Zhireken Shakhtama Aksug Siberia,Russia

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