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  Subjects -> EARTH SCIENCES (Total: 654 journals)
    - EARTH SCIENCES (468 journals)
    - GEOLOGY (73 journals)
    - GEOPHYSICS (28 journals)
    - HYDROLOGY (22 journals)
    - OCEANOGRAPHY (63 journals)

EARTH SCIENCES (468 journals)                  1 2 3 | Last

Showing 1 - 200 of 371 Journals sorted alphabetically
Acta Geochimica     Hybrid Journal   (Followers: 3)
Acta Geodaetica et Geophysica     Hybrid Journal   (Followers: 1)
Acta Geodaetica et Geophysica Hungarica     Full-text available via subscription   (Followers: 2)
Acta Geophysica     Open Access   (Followers: 6)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Meteorologica Sinica     Hybrid Journal   (Followers: 3)
Advances in High Energy Physics     Open Access   (Followers: 20)
Advances In Physics     Hybrid Journal   (Followers: 19)
Aeolian Research     Hybrid Journal   (Followers: 5)
African Journal of Aquatic Science     Hybrid Journal   (Followers: 13)
Algological Studies     Full-text available via subscription   (Followers: 2)
Alpine Botany     Hybrid Journal   (Followers: 4)
AMBIO     Hybrid Journal   (Followers: 14)
Anales del Instituto de la Patagonia     Open Access   (Followers: 1)
Andean geology     Open Access   (Followers: 13)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3)
Annales UMCS, Geographia, Geologia, Mineralogia et Petrographia     Open Access  
Annals of Geophysics     Open Access   (Followers: 13)
Annals of GIS     Hybrid Journal   (Followers: 21)
Annual Review of Marine Science     Full-text available via subscription   (Followers: 11)
Anthropocene     Hybrid Journal   (Followers: 3)
Anthropocene Review     Hybrid Journal   (Followers: 6)
Applied Clay Science     Hybrid Journal   (Followers: 4)
Applied Geochemistry     Hybrid Journal   (Followers: 12)
Applied Geomatics     Hybrid Journal   (Followers: 3)
Applied Geophysics     Hybrid Journal   (Followers: 7)
Applied Ocean Research     Hybrid Journal   (Followers: 5)
Applied Petrochemical Research     Open Access   (Followers: 2)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 34)
Arctic Science     Open Access   (Followers: 6)
Arctic, Antarctic, and Alpine Research     Full-text available via subscription   (Followers: 9)
Artificial Satellites : The Journal of Space Research Centre of Polish Academy of Sciences     Open Access   (Followers: 18)
Asia-Pacific Journal of Atmospheric Sciences     Hybrid Journal   (Followers: 20)
Asian Journal of Earth Sciences     Open Access   (Followers: 20)
Asian Review of Environmental and Earth Sciences     Open Access   (Followers: 1)
Atlantic Geology : Journal of the Atlantic Geoscience Society / Atlantic Geology : revue de la Société Géoscientifique de l'Atlantique     Full-text available via subscription   (Followers: 10)
Atmosphere-Ocean     Full-text available via subscription   (Followers: 12)
Atmospheric and Climate Sciences     Open Access   (Followers: 28)
Australian Journal of Earth Sciences: An International Geoscience Journal of the Geological Society of Australia     Hybrid Journal   (Followers: 11)
Boletim de Ciências Geodésicas     Open Access  
Boreas: An International Journal of Quaternary Research     Hybrid Journal   (Followers: 10)
Bragantia     Open Access   (Followers: 2)
Bulletin of Earthquake Engineering     Hybrid Journal   (Followers: 11)
Bulletin of Geosciences     Open Access   (Followers: 8)
Bulletin of the Lebedev Physics Institute     Hybrid Journal   (Followers: 1)
Bulletin of the Seismological Society of America     Full-text available via subscription   (Followers: 21)
Bulletin of Volcanology     Hybrid Journal   (Followers: 17)
Cadernos de Geociências     Open Access  
Canadian Mineralogist     Full-text available via subscription   (Followers: 3)
Canadian Water Resources Journal     Hybrid Journal   (Followers: 21)
Carbonates and Evaporites     Hybrid Journal   (Followers: 3)
CATENA     Hybrid Journal   (Followers: 5)
Chemical Geology     Hybrid Journal   (Followers: 18)
Chemie der Erde - Geochemistry     Hybrid Journal   (Followers: 4)
Chinese Geographical Science     Hybrid Journal   (Followers: 5)
Chinese Journal of Oceanology and Limnology     Hybrid Journal   (Followers: 4)
Ciencia del suelo     Open Access   (Followers: 2)
Ciencias Espaciales     Open Access  
Climate and Development     Hybrid Journal   (Followers: 12)
Coastal Management     Hybrid Journal   (Followers: 25)
Cogent Geoscience     Open Access  
Comptes Rendus Geoscience     Full-text available via subscription   (Followers: 8)
Computational Geosciences     Hybrid Journal   (Followers: 13)
Computational Mathematics and Mathematical Physics     Hybrid Journal   (Followers: 2)
Computers and Geotechnics     Hybrid Journal   (Followers: 10)
Contemporary Trends in Geoscience     Open Access   (Followers: 3)
Continental Shelf Research     Hybrid Journal   (Followers: 9)
Contributions to Mineralogy and Petrology     Hybrid Journal   (Followers: 10)
Contributions to Plasma Physics     Hybrid Journal   (Followers: 3)
Coral Reefs     Hybrid Journal   (Followers: 16)
Cretaceous Research     Hybrid Journal   (Followers: 6)
Cybergeo : European Journal of Geography     Open Access   (Followers: 5)
Depositional Record     Open Access  
Developments in Geotectonics     Full-text available via subscription   (Followers: 3)
Developments in Quaternary Science     Full-text available via subscription   (Followers: 3)
Développement durable et territoires     Open Access   (Followers: 3)
Diatom Research     Hybrid Journal   (Followers: 2)
Doklady Physics     Hybrid Journal   (Followers: 1)
Dynamics of Atmospheres and Oceans     Hybrid Journal   (Followers: 11)
E&S Engineering and Science     Open Access  
E3S Web of Conferences     Open Access  
Earth and Planetary Science Letters     Hybrid Journal   (Followers: 111)
Earth and Space Science     Open Access   (Followers: 12)
Earth Interactions     Full-text available via subscription   (Followers: 11)
Earth Science Research     Open Access   (Followers: 5)
Earth Surface Dynamics (ESurf)     Open Access   (Followers: 4)
Earth Surface Processes and Landforms     Hybrid Journal   (Followers: 19)
Earth System Dynamics     Open Access   (Followers: 6)
Earth System Dynamics Discussions     Open Access   (Followers: 4)
Earth's Future     Open Access   (Followers: 1)
Earth, Planets and Space     Open Access   (Followers: 67)
Earthquake Engineering and Engineering Vibration     Hybrid Journal   (Followers: 8)
Earthquake Science     Hybrid Journal   (Followers: 11)
Earthquake Spectra     Full-text available via subscription   (Followers: 18)
Ecohydrology     Hybrid Journal   (Followers: 11)
Ecological Questions     Open Access   (Followers: 7)
Electromagnetics     Hybrid Journal   (Followers: 5)
Energy Efficiency     Hybrid Journal   (Followers: 11)
Energy Exploration & Exploitation     Hybrid Journal   (Followers: 4)
Environmental Earth Sciences     Hybrid Journal   (Followers: 24)
Environmental Geology     Hybrid Journal   (Followers: 20)
Environmental Geosciences     Full-text available via subscription   (Followers: 4)
Environmental Geotechnics     Hybrid Journal   (Followers: 5)
Erwerbs-Obstbau     Hybrid Journal  
Estuaries and Coasts     Hybrid Journal   (Followers: 18)
Estuarine, Coastal and Shelf Science     Hybrid Journal   (Followers: 33)
Estudios Geográficos     Open Access  
European Journal of Mineralogy     Full-text available via subscription   (Followers: 13)
European Journal of Remote Sensing     Open Access  
Exploration Geophysics     Hybrid Journal   (Followers: 4)
Facies     Hybrid Journal   (Followers: 9)
Fieldiana Life and Earth Sciences     Full-text available via subscription   (Followers: 1)
Física de la Tierra     Open Access  
Folia Musei rerum naturalium Bohemiae occidentalis. Geologica et Paleobiologica     Open Access  
Folia Quaternaria     Open Access  
Forestry Chronicle     Full-text available via subscription   (Followers: 10)
Frontiers in Earth Science     Open Access   (Followers: 5)
Frontiers in Geotechnical Engineering     Open Access   (Followers: 3)
Frontiers of Earth Science     Hybrid Journal   (Followers: 8)
Fundamental and Applied Limnology / Archiv für Hydrobiologie     Full-text available via subscription   (Followers: 4)
GEM - International Journal on Geomathematics     Hybrid Journal   (Followers: 1)
Geo-Marine Letters     Hybrid Journal   (Followers: 7)
Geoacta     Open Access   (Followers: 4)
Geobiology     Hybrid Journal   (Followers: 8)
Geocarto International     Hybrid Journal   (Followers: 22)
Geochemical Perspectives     Hybrid Journal  
Geochemistry : Exploration, Environment, Analysis     Hybrid Journal   (Followers: 7)
Geochemistry, Geophysics, Geosystems     Full-text available via subscription   (Followers: 26)
Geochimica et Cosmochimica Acta     Hybrid Journal   (Followers: 47)
Geochronometria     Hybrid Journal   (Followers: 3)
Geoderma Regional : The International Journal for Regional Soil Research     Full-text available via subscription   (Followers: 3)
Geodinamica Acta     Hybrid Journal   (Followers: 3)
Geodynamics & Tectonophysics     Open Access   (Followers: 1)
Geoenvironmental Disasters     Open Access   (Followers: 3)
Geofluids     Open Access   (Followers: 4)
Geoforum     Hybrid Journal   (Followers: 22)
Géographie physique et Quaternaire     Full-text available via subscription   (Followers: 1)
Geography and Natural Resources     Hybrid Journal   (Followers: 7)
Geoheritage     Hybrid Journal   (Followers: 1)
Geoinformatica Polonica : The Journal of Polish Academy of Arts and Sciences     Open Access  
Geoinformatics & Geostatistics     Hybrid Journal   (Followers: 9)
Geological Journal     Hybrid Journal   (Followers: 14)
Geology Today     Hybrid Journal   (Followers: 25)
Geology, Geophysics and Environment     Open Access   (Followers: 1)
Geomagnetism and Aeronomy     Hybrid Journal   (Followers: 3)
Geomatics, Natural Hazards and Risk     Hybrid Journal   (Followers: 9)
Geomechanics for Energy and the Environment     Full-text available via subscription   (Followers: 1)
GEOmedia     Open Access   (Followers: 1)
Geomorphology     Hybrid Journal   (Followers: 27)
Geophysical & Astrophysical Fluid Dynamics     Hybrid Journal   (Followers: 2)
Geophysical Journal International     Hybrid Journal   (Followers: 31)
Geophysical Prospecting     Hybrid Journal   (Followers: 7)
Geophysics     Full-text available via subscription   (Followers: 18)
GeoResJ     Hybrid Journal  
Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards     Hybrid Journal   (Followers: 8)
Geoscience Canada : Journal of the Geological Association of Canada / Geoscience Canada : journal de l'Association Géologique du Canada     Full-text available via subscription   (Followers: 3)
Geoscience Data Journal     Open Access   (Followers: 2)
Geoscience Frontiers     Open Access   (Followers: 9)
Geoscience Letters     Open Access   (Followers: 1)
Geoscience Records     Open Access  
Geosciences     Open Access   (Followers: 2)
Geosciences Journal     Hybrid Journal   (Followers: 10)
Geoscientific Instrumentation, Methods and Data Systems     Open Access   (Followers: 4)
Geoscientific Model Development     Open Access   (Followers: 2)
Geostandards and Geoanalytical Research     Hybrid Journal   (Followers: 2)
Geosystem Engineering     Hybrid Journal   (Followers: 1)
Geotectonic Research     Full-text available via subscription   (Followers: 5)
Geotectonics     Hybrid Journal   (Followers: 7)
GISAP : Earth and Space Sciences     Open Access   (Followers: 2)
Glass Physics and Chemistry     Hybrid Journal   (Followers: 4)
Global and Planetary Change     Hybrid Journal   (Followers: 17)
Global Biogeochemical Cycles     Full-text available via subscription   (Followers: 15)
Gondwana Research     Hybrid Journal   (Followers: 7)
GPS Solutions     Hybrid Journal   (Followers: 17)
Grassland Science     Hybrid Journal  
Ground Water     Hybrid Journal   (Followers: 34)
Ground Water Monitoring & Remediation     Hybrid Journal   (Followers: 19)
Groundwater for Sustainable Development     Full-text available via subscription   (Followers: 1)
Helgoland Marine Research     Open Access   (Followers: 3)
History of Geo- and Space Sciences     Open Access   (Followers: 4)
Hydrobiologia     Hybrid Journal   (Followers: 18)
Hydrogeology Journal     Hybrid Journal   (Followers: 18)
Hydrological Processes     Hybrid Journal   (Followers: 27)
Hydrology and Earth System Sciences     Open Access   (Followers: 28)
ICES Journal of Marine Science: Journal du Conseil     Hybrid Journal   (Followers: 54)
IEEE Journal of Oceanic Engineering     Hybrid Journal   (Followers: 12)
Indian Geotechnical Journal     Hybrid Journal   (Followers: 4)
Indonesian Journal on Geoscience     Open Access   (Followers: 2)
Interdisciplinary Environmental Review     Hybrid Journal   (Followers: 3)
International Geology Review     Hybrid Journal   (Followers: 14)
International Journal of Advanced Geosciences     Open Access  
International Journal of Advanced Remote Sensing and GIS     Open Access   (Followers: 35)
International Journal of Advancement in Earth and Enviromental Sciences     Open Access   (Followers: 3)
International Journal of Advancement in Remote Sensing, GIS, and Geography     Open Access   (Followers: 27)
International Journal of Applied Earth Observation and Geoinformation     Hybrid Journal   (Followers: 36)
International Journal of Coal Geology     Hybrid Journal   (Followers: 2)
International Journal of Disaster Risk Reduction     Hybrid Journal   (Followers: 15)
International Journal of Earth Sciences     Hybrid Journal   (Followers: 35)
International Journal of Earthquake and Impact Engineering     Hybrid Journal   (Followers: 2)
International Journal of Forest, Soil and Erosion     Open Access   (Followers: 6)

        1 2 3 | Last

Journal Cover Chemie der Erde - Geochemistry
  [SJR: 0.881]   [H-I: 34]   [4 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0009-2819
   Published by Elsevier Homepage  [3034 journals]
  • Trace elements indicating humid climatic events in the
           Ordovician–early Silurian
    • Abstract: Publication date: Available online 8 June 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Enli Kiipli, Tarmo Kiipli, Toivo Kallaste, Siim Pajusaar
      The chemical composition of the clay fraction separated from the carbonate rock of the north-eastern Baltoscandian Basin was analysed and interpreted. Increased contents of Rb, Zr, Nb, Ti and their Al2O3-normalised ratios were detected at several stratigraphical levels in the geological sections of the Middle Ordovician–Upper Llandovery. In the weathering areas, Rb, Zr, Nb, Ti and Al are sensitive to moist conditions in the clay-forming process. In the sedimentary basin, the contents of these elements in clay are preserved and allow to infer past climates. Humid events occurred in the Dapingian, Sandbian, early Katian and Hirnantian (Ordovician) and in the Middle and Late Llandovery (Silurian). Juxtaposition with the sea-level curve shows correlation of five humid climate intervals with eustatic transgressions, suggesting global causes for these climatic changes. The warm and humid events, lasting one to two million years, occurred as climaxes between ice ages. An exceptional humid event within the Hirnantian glacial time occurs during mid-Hirnantian transgression, i.e. at a time of relative warming, as well.

      PubDate: 2017-06-11T19:14:41Z
       
  • Editorial board members
    • Abstract: Publication date: May 2017
      Source:Chemie der Erde - Geochemistry, Volume 77, Issue 2


      PubDate: 2017-06-11T19:14:41Z
       
  • Tectonic regime switchover of Triassic Western Qinling Orogen: Constraints
           from LA-ICP-MS zircon U–Pb geochronology and Lu–Hf isotope of
           Dangchuan intrusive complex in Gansu, China
    • Abstract: Publication date: Available online 4 June 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Jian-Zhen Geng, Kun-Feng Qiu, Zong-Yang Gou, Hao-Cheng Yu
      The Qinling Orogenic Belt, linking the Kunlun and Qilian Mountains to the west and continuing farther east to the Dabie Mountain, was assembled by the convergence and collision between the Greater South China and the North China blocks. The precise timing of the subduction and collision processes between these continental blocks and tectonic regime switchover is very equivocal. Zircon in-situ LA-ICP-MS U–Pb dating in this contribution indicates that the biotite monzogranite and monzogranite phases of the Dangchuan complex were crystallized at ca. 239.8±2.3Ma and 227.8±1.2Ma, respectively. The ca. 240Ma biotite monzogranite displays εHf(t) values ranging from −2.4 to +2.9, and corresponding TDM2 of 1.72–1.94Ga and TDM1 of 0.77–0.88Ga. The ca. 228Ma monzogranite exhibits εHf(t) values ranging from −4.3 to +1.9, and corresponding TDM2 of 1.73–2.08Ga and TDM1 of 0.81–0.88Ga. Lutetium–Hf isotopic composition indicates that the biotite monzogranite and monzogranite probably have the same parental magmas which were originated from hybrid sources of both reworking of Paleoproterozoic ancient crust and partial melting of the Neoproterozoic juvenile crust. The more negative εHf(t) values of the monzogranite suggest more contribution of the ancient crust during the source contamination, or more possible crustal assimilation during their crystallization at ca. 228Ma than precursor biotite monzogranite. Integrated with previous research and our detailed petrography, we propose that the Dangchuan complex underwent an episodic growth documenting the tectonic regime switchover from early Paleozoic to Triassic. The ca. 439Ma inherited zircon recorded the persistent subduction of the oceanic crust, the ca. 240Ma biotite monzogranite emplaced during the northward subduction of the Mianlue oceanic crust beneath the South Qinling block, and the ca. 228Ma monzogranite emplaced during the syn-collisional process in a compressional setting.

      PubDate: 2017-06-06T18:48:54Z
       
  • Geochemical characteristics of stream sediments from an urban-volcanic
           zone, Central Mexico: Natural and man-made inputs
    • Abstract: Publication date: Available online 9 May 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): V.C. Shruti, M.P. Jonathan, P.F. Rodríguez-Espinosa, R. Nagarajan, D.C. Escobedo-Urias, S.S. Morales-García, E. Martínez-Tavera
      Geochemical characteristics of stream sediments [n=31; Upstream section: Zahuapan River (1–12) and Atoyac River (13–20); Downstream section (21–31)] from Atoyac River basin of Central Mexico have been evaluated. The study focuses on the textural, petrography and chemical composition of the fluvial sediments with the aim of analyzing their provenance, the chemical weathering signature and their potential environmental effects. The fluvial sediments are mostly composed of sand and silt sized particles dominated by plagioclase, pyroxenes, amphiboles, K-feldspar, biotite, opaque and quartz. The sediments were analyzed for determination of major (Al, Fe, Ca, Mg, Na, K, P, Si, Ti), trace elements (As, Ba, Be, Co, Cr, Cu, Mo, Mn, Ni, Pb, Sc, V, Y, Zn, Zr, Ga) and compared with Upper continental crust (UCC), source area composition and local background values. The elemental concentrations were comparable with the average andesite and dacitic composition of the source area and the local background values except for enrichment of Cu (56.27ppm), Pb (34ppm) and Zn (235.64ppm) in the downstream sediments suggesting a significant external influence (anthropogenic). The fluvial sediments of Atoyac River basin display low CIA and PIA values implying predominantly weak to moderate weathering conditions in the source region. Based on the provenance discrimination diagrams and elemental ratios, it is understood that the collected sediments are derived from intermediate to felsic volcanic rocks dominated in the study region. Metal contamination indices highlight the enrichment of Cu, Pb, Zn, Mo, Cr and S clearly indicating the influences from natural (weathering and volcanic activity) and external (anthropogenic) sources. Ecological risk assessment results indicate that Cr, Ni and Zn will cause adverse biological effects to the riverine environment.
      Graphical abstract image

      PubDate: 2017-05-13T04:56:45Z
       
  • Geochemistry and petrogenesis of Kolah-Ghazi granitoids of Iran: Insights
           into the Jurassic Sanandaj-Sirjan magmatic arc
    • Abstract: Publication date: Available online 29 April 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Marzieh Bayati, Dariush Esmaeily, Reza Maghdour-Mashhour, Xian-Hua Li, Robert J. Stern
      Kolah-Ghazi granitoid (KGG), situated in the southern part of the Sanandaj–Sirjan Zone (SNSZ), Iran, is a peraluminous, high K calc-alkaline, cordierite-bearing S-type body that is mainly composed of monzogranite, granodorite and syenogranite. Zircon U–Pb ages indicate that the crystallization of the main body occurred from 175 Ma to 167 Ma. Two kinds of xenoliths are found in KKG rocks: (i) xenoliths of partially melted pelites including cordierite xenocrysts and aluminoslicates, and (ii) mafic microgranular enclaves that reflect the input of mantle-derived mafic magmas. Field observations and geochemical data of KGG rocks are consistent with their derivation from a multiple sources including melts of metasediments and mantle-derived melts. We infer that these magmas originated by the anatexis of a metasedimentary source (mixture of metapelite and metagreywacke) in the mid- to lower-crust under low water-vapor pressures (0.5-1 Kbar) and temperature of ∼800°C. KGG is the product of biotite incongruent melting of this metasedimentary source. S-type granites are commonly thought to be produced in continent-continent collision tectonic environment. However, trace element discrimination diagrams show that S-type KGG rocks formed in an arc-related environment. The roll-back of Neo- Tethyan subducting slab accompanying oblique subduction in Late Triassic to Early Jurassic time induced trench rollback, back arc basin opening and filling with turbidite flysch and molasse- type siliciclastic sediments of the Shemshak Group on the overriding plate. Further changes in the subducting slab to flat subduction in Middle Jurassic time, the time of peak magmatism in the SNSZ, led to thickening and high temperature-low pressure metamorphism of the backarc turbidite deposits and consequent anatexis of the metasedimentary source to produce the KGG S- type rocks along with several other I-type granitoids in the SNSZ.

      PubDate: 2017-05-02T04:03:04Z
       
  • Utilization of sodium waterglass from sugar cane bagasse ash as a new
           alternative hardener for producing metakaolin-based geopolymer cement
    • Abstract: Publication date: Available online 24 April 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Hervé Kouamo Tchakouté, Claus Henning Rüscher, Malte Hinsch, Jean Noël Yankwa Djobo, Elie Kamseu, Cristina Leonelli
      Sugar cane bagasse ash from SOSUCAM company in Cameroon was used to synthesize sodium waterglass as a new alternative hardener. The new hardener was used to prepare metakaolin-based geopolymer cements. The compressive strength of the resulting geopolymer cement cured at room temperature for 28days was 32.9MPa. Samples soaked for 28 days in water in parallel experiments revealed a strength of 31.4MPa. This shows that exposure of water does not lead to any weakening. The value of water absorption was 7.1% in the water-soaked cements, indicating the presence of fewer pores and voids than in the dry cements. However, in SEM micrographs, the microstructure of geopolymer cement appears rather homogeneous and compact without any change by water soaking. It can thus be concluded that sodium waterglass from sugar cane bagasse ash can be used as an alternative hardener or reactive ingredient for producing geopolymer cement with a high degree of cross-linking geopolymer framework. The use of this low-value silica-rich waste for producing sodium waterglass results in environmental benefits including a significant reduction of CO2 emission and energy consumption compared to the production of commercial sodium waterglass.

      PubDate: 2017-04-25T03:34:32Z
       
  • Mopping up leaking carbon: A natural analog at Wadi Namaleh, Jordan
    • Abstract: Publication date: Available online 18 April 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Nizar Abu-Jaber
      Carbon capture and sequestration (CCS) is one of the important options available for partially stemming greenhouse gas emissions from large point sources. The possibility of leaking from deep storage needs to be addressed. The Wadi Namaleh area in southern Jordan provides an interesting case study of how excess CO2 can be trapped in the form of carbonates in the near surface, even when the local geology is not obviously conducive for such a process. Carbonate veins are formed in surface alteration zones of rhyolite host rock in this arid region. The alteration zones are limited to areas where surface soil or colluvium are present. Oxygen, deuterium and carbon isotopes of the carbonates and near-surface ground water in the area suggest that the source of carbon is deep seated CO2, and that the carbonate precipitated in local meteoric water under ambient temperature conditions. Analysis of strontium in the carbonate, fresh rhyolite and altered host shows that the source for calcium is aeolian. Trace elements show that metal and REE mobility are constrained to the alteration zone. Thus, interaction of H2O, CO2 and atmospheric wet and dry deposition lead to the formation of the clayey (montmorillonite) alteration zone. This zone acts to trap seeping CO2 and water, and thus produces conditions of progressively more efficient trapping of carbon dioxide by means of a positive feedback mechanism. Replication of these conditions in other areas will minimize CO2 leakage from man-made CCS sites.

      PubDate: 2017-04-25T03:34:32Z
       
  • Editorial board members
    • Abstract: Publication date: April 2017
      Source:Chemie der Erde - Geochemistry, Volume 77, Issue 1


      PubDate: 2017-04-25T03:34:32Z
       
  • Meteoritic minerals and their origins
    • Abstract: Publication date: Available online 30 March 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Alan E. Rubin, Chi Ma
      About 435 mineral species have been identified in meteorites including native elements, metals and metallic alloys, carbides, nitrides and oxynitrides, phosphides, silicides, sulfides and hydroxysulfides, tellurides, arsenides and sulfarsenides, halides, oxides, hydroxides, carbonates, sulfates, molybdates, tungstates, phosphates and silico phosphates, oxalates, and silicates from all six structural groups. The minerals in meteorites can be categorized as having formed by a myriad of processes that are not all mutually distinct: (1) condensation in gaseous envelopes around evolved stars (presolar grains), (2) condensation in the solar nebula, (3) crystallization in CAI and AOI melts, (4) crystallization in chondrule melts, (5) exsolution during the cooling of CAIs, (6) exsolution during the cooling of chondrules and opaque assemblages, (7) annealing of amorphous material, (8) thermal metamorphism and exsolution, (9) aqueous alteration, hydrothermal alteration and metasomatism, (10) shock metamorphism, (11) condensation within impact plumes, (12) crystallization from melts in differentiated or partially differentiated bodies, (13) condensation from late-stage vapors in differentiated bodies, (14) exsolution, inversion and subsolidus redox effects within cooling igneous materials, (15) solar heating near perihelion, (16) atmospheric passage, and (17) terrestrial weathering.

      PubDate: 2017-04-04T02:33:31Z
       
  • C-N elemental and isotopic investigation in agricultural soils: Insights
           on the effects of zeolitite amendments
    • Abstract: Publication date: Available online 6 March 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Giacomo Ferretti, Dario Di Giuseppe, Claudio Natali, Barbara Faccini, Gianluca Bianchini, Massimo Coltorti
      In this paper we present an elemental and isotopic investigation of carbon and nitrogen in the soil-plant system. Plants grown in an unamended soil were compared to plants grown in a soil amended with natural and NH4 +-enriched zeolitites. The aim was to verify that zeolitites at natural state increase the chemical fertilization efficiency and the nitrogen transfer from NH4 +-enriched zeolitites to plants. Results showed that plants grown on plots amended with zeolitites have generally a δ15N approaching that of chemical fertilizers, suggesting an enhanced nitrogen uptake from this specific N source with respect to the unamended plot. The δ15N of plants grown on NH4 +-enriched zeolitites was strongly influenced by pig-slurry δ15N (employed for the enrichment process), confirming the nitrogen transfer from zeolitites to plants. The different agricultural practices are also reflected in the plant physiology as recorded by the carbon discrimination factor, which generally increases in plots amended with natural zeolitites, indicating better water/nutrient conditions.

      PubDate: 2017-03-09T00:45:37Z
       
  • Geology, geochemistry and petrogenesis of post-collisional adakitic
           intrusions and related dikes in the Khoynarood area, NW Iran
    • Abstract: Publication date: Available online 21 February 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Hossein Mahmoudi Nia, Saeid Baghban, Vartan Simmonds
      The Khoynarood area is located in the northwest of Iran, lying at the northwestern end of the Urumieh–Dokhtar volcano-plutonic belt and being part of the Qaradagh–South Armenia domain. The main intrusive rocks outcropped in the area have compositions ranging from monzonite–quartz monzonite, through granodiorite, to diorite–hornblende diorite, accompanied by several dikes of diorite–quartz diorite and hornblende diorite compositions, which were geochemically studied in order to provide further data and evidence for the geodynamic setting of the region. The SiO2, Al2O3 and MgO contents of these rocks are about 58.32–68.12%, 14.13–18.65% and 0.68–4.27%, respectively. They are characterized by the K2O/Na2O ratio of 0.26–0.58, Fe2O3 +MnO+MgO+TiO2 content about 4.27–13.13%, low Y (8–17ppm) and HREE (e.g., 1–2ppm Yb) and high Sr contents (750–1330ppm), as well as high ratios of Ba/La (13.51–50.96), (La/Yb)N (7–22), Sr/Y (57.56–166.25), Rb/La (1.13–2.96) and La/Yb (10–33.63), which may testify to the adakitic nature of these intrusions. Their chemical composition corresponds to high-silica adakites, displaying enrichments of LREEs and LILEs and preferential depletion of HFSEs, (e.g., Ti, Ta and Nb). The REE differentiation pattern and the low HREE and Y contents might be resulted from the presence of garnet and amphibole in the solid residue of the source rock, while the high Sr content and the negative anomalies of Ti, Ta and Nb may indicate the absence of plagioclase and presence of Fe and Ti oxides in it. As a general scenario, it may be concluded that the adakitic rocks in the Khoynarood were most likely resulted from detachment of the subducting Neo-Tethyan eclogitic slab after subduction cessation between Arabian and Central Iranian plates during the upper Cretaceous–early Cenozoic and partial melting of the detached slab, followed by interactions with metasomatized mantle wedge peridotite and contamination with continental crust.

      PubDate: 2017-02-23T17:39:49Z
       
  • Relationship among geochemical elements in soil and grapes as terroir
           fingerprintings in Vitis vinifera L. cv. “Glera”
    • Abstract: Publication date: Available online 8 February 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Salvatore Pepi, Luigi Sansone, Milvia Chicca, Carmela Vaccaro
      Prosecco, one of the most popular sparkling wines in the world, is produced in Italy. For this reason, it is important to develop a scientific method for determining geographic origin in order to prevent fraudulent labelling. To establish the relationship between geochemistry of vineyard soil and chemical composition of grape, a geochemical characterization of “Glera”, a Vitis vinifera cultivar from Italian Region, Veneto was undertaken. We evaluated the relationship between major and trace elements in soil and their concentrations in “Glera” grape berries in vineyards belonging to five localities in the Veneto alluvial plain, all included in the Controlled Designation of Origin (DOC) area of Prosecco. A statistically significant correspondence between the soil and grape was observed for Sr. Multivariate analysis (LDA) allowed discrimination of samples of soil and grape berries from each single winery according to the geographic origin. The elements that could establish a reliable correspondence between the geolithological features of the vineyard soil and the chemical composition of grape berries are: Sr, Ba, Ca, Mg, Al, K, Zn, B, Ni, Co.

      PubDate: 2017-02-10T16:30:51Z
       
  • Geochemistry of S, Cu, Ni, Cr and Au-PGE in the garnet amphibolites from
           the Akom II area in the Archaean Congo Craton, Southern Cameroon
    • Abstract: Publication date: Available online 4 February 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Beyanu Anehumbu Aye, Elisé Sababa, Paul-Désiré Ndjigui
      The fresh and weathered garnet amphibolites, from the Akom II area in the Archaean Congo Craton, were investigated to determine the S, Cu, Ni, Cr, and Au-PGE values. The garnet amphibolites are composed of amphibole, plagioclase, garnet, quartz, and accessory apatite, spinel, sericite, pyrite, chalcopyrite and non-identified opaque minerals. The presence of apatite, sericite, and two generations of opaque minerals suggests that they might be affected by hydrothermal alteration. They are characterized by moderate Al2O3, Fe2O3, CaO, V, Zn, and Co contents with negative Eu- and Ce-anomalies. The sulfur concentrations are variable (380–1710ppm). According to the sulfur contents, amphibolites can be grouped into two: amphibolites with low contents, ranging between 380 and 520ppm (av.=457ppm); and amphibolites with elevated contents, varying from 1140 to 1710ppm (av.=1370ppm). Amphibolites contain contrast amounts of Cu (∼1800 to 5350ppm) while nickel contents attain 121ppm. Chromium contents vary from 43 to 194ppm. Sulfur correlates positively with Cu and Cr, but negatively with Ni and Ni/Cr ratio. The total Au-PGE contents attain 59ppb. The presence of amphibole and feldspars confirms the low degree of amphibolite weathering. The secondary minerals are constituted of kaolinite, gibbsite, goethite and hematite. Despite the accumulation of some elements, the major and trace element distribution is quite similar to that of fresh amphibolites. Nevertheless, the weathering processes lead to the depletion of several elements such as S (239–902ppm), Cu (520–2082ppm), and Ni (20–114ppm). Chromium and Au-PGE show an opposite trend marked by a slight enrichment in the weathered amphibolites. Amidst the Au-PGE, Pd (60ppb) and Pt (23ppb) have elevated contents in the fresh rocks as well as in the weathered materials. The PPGE contents are much higher than IPGE contents in both types of materials. The Pd/Pt, Pd/Rh, Pd/Ru, Pd/Ir, Pd/Os, and Pd/Au values indicate that Pt, Rh, Ru, Ir, Os and Au are more mobile than Pd. Chondrite-normalized base metal patterns confirm the abundance of Pd and the slight enrichment of Au-PGE in weathered rocks. Palladium, Rh and Ir are positively correlated with S. Conversely Pt and Ru are negatively correlated with S and Au is not correlated with S. Despite the high and variable S and Cu contents, the garnet amphibolites possess low Au-PGE and other base metals contents.

      PubDate: 2017-02-10T16:30:51Z
       
  • Geochemistry and petrogenesis of Soltan Maidan basalts (E Alborz, Iran):
           Implications for asthenosphere-lithosphere interaction and rifting along
           the N margin of Gondwana
    • Abstract: Publication date: Available online 1 February 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Morteza Derakhshi, Habibollah Ghasemi, Laicheng Miao
      Soltan Maidan Basaltic Complex with thickness up to about 1300m is located in the eastern Alborz zone, north of Iran. This complex is dominantly composed of transitional to mildly alkaline basaltic lava flows, agglomerates and tuffs, together with a few thin sedimentary interlayers. Field geological evidence and study of palynomorph assemblages in the shale interlayer show Late Ordovician to Early Late Silurian ages. Chondrite- and primitive-mantle normalized multi-element patterns of Soltan Maidan basalts demonstrate enrichment in highly incompatible elements relative to less incompatible ones and their patterns are most similar to OIB. Trace elemental and Sr-Nd isotopic compositions indicate interaction and mixing of asthenospheric mantle source (OIB-type) with enriched subcontinental lithospheric mantle components (EM1-type). This asthenosphere-lithosphere interaction occurred in an extensional continental setting, which resulted in opening of the Paleotethys Ocean in the north of Gondwana during the Late Silurian to Middle Devonian.

      PubDate: 2017-02-03T15:17:16Z
       
  • Zr-in-rutile thermometry of eclogites from the Karakaya Complex in NW
           Turkey: Implications for rutile growth during subduction zone metamorphism
           
    • Abstract: Publication date: Available online 31 January 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Firat Şengün
      Eclogites occur as a tectonic slice within a metabasite-phyllite-marble unit of the Karakaya Complex in northwest Turkey. The high-pressure mineral assemblage in eclogite is mainly composed of garnet+omphacite+glaucophane+epidote+quartz. Trace element characteristics of rutile and Zr-in-rutile temperatures were determined for eclogites from the Karakaya Complex. Core-rim analyses of rutile grains yield remarkable trace element zoning with lower contents of Zr, Nb and Ta in the core than in the rim. The variations in Zr, Nb and Ta can be ascribed to growth zoning rather than diffusion effects. The Nb/Ta and Zr/Hf ratios increase with a decrease in Ta and Hf contents, which could be ascribed to the effect of metamorphic dehydration in subduction zones on rutile Nb/Ta differentiation. The rutile grains from eclogites in the Karakaya Complex are dominated by subchondritic Nb/Ta and Zr/Hf ratios. It can be noted that subchondritic Nb/Ta may record rutile growth from local sinks of aqueous fluids from metamorphic dehydration. The Zr contents of all rutile grains range between 81 and 160ppm with an average of 123ppm. The Zr-in-rutile thermometry yields temperatures of 559–604°C with an average temperature of 585°C for eclogites from the Karakaya Complex. This average temperature suggests growth temperature of rutile before peak pressure during the subduction. However, some rutile grains have higher Zr contents in the outermost rims compared to the core. Zr-in-rutile temperatures of the rims are about 20°C higher than those of the cores. This suggests that the outermost rims would have grown from a distinct fluid at higher temperatures than that of the cores. Moreover, Zr contents and calculated temperatures in both inclusion rutile and matrix rutile from eclogites are identical, which suggests that eclogites within the Karakaya Complex belong to the same tectonic slice and underwent similar metamorphic evolution.

      PubDate: 2017-02-03T15:17:16Z
       
  • Origin of highly siderophile and chalcogen element fractionations in the
           components of unequilibrated H and LL chondrites
    • Abstract: Publication date: Available online 29 January 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Yogita Kadlag, Harry Becker
      Osmium isotopic compositions, abundances of highly siderophile elements (HSE: platinum group elements, Re and Au), the chalcogen elements S, Se and Te and major and minor elements were analysed in physically separated size fractions and components of the ordinary chondrites WSG 95300 (H3.3, meteorite find) and Parnallee (LL3.6, meteorite fall). Fine grained magnetic fractions are 268-65 times enriched in HSE compared to the non-magnetic fractions. A significant deviation of some fractions of WSG 95300 from the 4.568 Ga 187Re-187Os isochron was caused by redistribution of Re due to weathering of metal. HSE abundance patterns show that at least four different types of HSE carriers are present in WSG 95300 and Parnallee. The HSE carriers display (i) CI chondritic HSE ratios, (ii) variable Re/Os ratios, (iii) lower than CI chondritic Pd/Ir and Au/Ir and (iv) higher Pt/Ir and Pt/Ru than in CI chondrites. These differences between components clearly indicate the loss of refractory HSE carrier phases before accretion of the components. Tellurium abundances correlate with Pd and are decoupled from S, suggesting that most Te partitioned into metal during the last high-temperature event. Tellurium is depleted in all fractions compared to CI chondrite normalized Se abundances. The depletion of Te is likely associated with the high temperature history of the metal precursors of H and LL chondrites and occurred independent of the metal loss event that depleted LL chondrites in siderophile elements. Most non-magnetic and slightly magnetic fractions have S/Se close to CI chondrites. In contrast, the decoupling of Te and Se from S in magnetic fractions suggests the influence of volatility and metal-silicate partitioning on the abundances of the chalcogen elements. The influence of terrestrial weathering on chalcogen element systematics of these meteorites appears to be negligible.

      PubDate: 2017-02-03T15:17:16Z
       
  • An improved EPMA analytical protocol for U-Th-Pbtotal dating in xenotime:
           Age constraints from polygenetic Mangalwar Complex, Northwestern India
    • Abstract: Publication date: Available online 27 January 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Pranjit Hazarika, Biswajit Mishra, Manoj Kumar Ozha, Kamal Lochan Pruseth
      EPMA U-Th-Pbtotal dating in U- and Th bearing minerals (e.g., monazite, zircon, and xenotime) is a low-cost and reliable technique used for retrieving age information from detrital, diagenetic and low to high-T metamorphic, as well as magmatic rocks. Although, the accuracy on measured ages obtained using EPMA is considered to be poor compared to isotopic ages, the superior spatial resolution, ability to integrate textural and age information by in-situ measurement, lack of sample damage and easier and cheaper data generation in EPMA make chemical dating a very valuable tool to decipher diverse petrological processes. This contribution presents an improved analytical protocol to obtain precise estimates of U, Th and Pb concentrations in xenotime. Results were tested on monazite standard (Moacyr pegmatite, Brazil; TIMS age: 487±1Ma) as the reference material. The proposed analytical protocol has been successfully applied to achieve an analytical uncertainty of less than 10% in U, Th and Pb measurements in xenotime. The protocol was further used to resolve polygenetic xenotime ages (ca. 1.82, 1.28 and 0.93Ga) in metapelite samples from the Mangalwar Complex, Northwestern India. Monazites in the same samples were also analyzed and found to preserve the two younger ages (i.e., ca. 1.28 and 1.0Ga). The obtained ages from the xenotime and monazite very well corroborate with the earlier published ages from the area validating the proposed analytical protocol.

      PubDate: 2017-02-03T15:17:16Z
       
  • The nature, origin and modification of insoluble organic matter in
           chondrites, the major source of Earth’s C and N
    • Abstract: Publication date: Available online 26 January 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): C.M.O’D. Alexander, G.D. Cody, B.T. De Gregorio, L.R. Nittler, R.M. Stroud
      All chondrites accreted ∼3.5wt.%C in their matrices, the bulk of which was in a macromolecular solvent and acid insoluble organic material (IOM). Similar material to IOM is found in interplanetary dust particles (IDPs) and comets. The IOM accounts for almost all of the C and N in chondrites, and a significant fraction of the H. Chondrites and, to a lesser extent, comets were probably the major sources of volatiles for the Earth and the other terrestrial planets. Hence, IOM was both the major source of Earth’s volatiles and a potential source of complex prebiotic molecules. Large enrichments in D and 15N, relative to the bulk solar isotopic compositions, suggest that IOM or its precursors formed in very cold, radiation-rich environments. Whether these environments were in the interstellar medium (ISM) or the outer Solar System is unresolved. Nevertheless, the elemental and isotopic compositions and functional group chemistry of IOM provide important clues to the origin(s) of organic matter in protoplanetary disks. IOM is modified relatively easily by thermal and aqueous processes, so that it can also be used to constrain the conditions in the solar nebula prior to chondrite accretion and the conditions in the chondrite parent bodies after accretion. Here we review what is known about the abundances, compositions and physical nature of IOM in the most primitive chondrites. We also discuss how the IOM has been modified by thermal metamorphism and aqueous alteration in the chondrite parent bodies, and how these changes may be used both as petrologic indicators of the intensity of parent body processing and as tools for classification. Finally, we critically assess the various proposed mechanisms for the formation of IOM in the ISM or Solar System.

      PubDate: 2017-01-27T18:42:47Z
       
  • The variability of δ34S and sulfur speciation in sediments of the
           Sulejów dam reservoir (Central Poland)
    • Abstract: Publication date: Available online 22 January 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Wojciech Drzewicki, Adriana Trojanowska-Olichwer, Mariusz Orion Jędrysek, Stanisław Hałas
      The study was carried out on the Sulejów dam reservoir (Central Poland). Water and sediment samples were collected between February and October 2006. Sulfur compounds in the sediment were chemically extracted and subjected to isotopic analysis. Large variability of SO4 2− concentration in the water column (from 10.3 to 36.2mg/dm3) and the isotopic composition of sulfur (δ34S from 2.1 to 5.4‰) was observed. The main identified sources of SO4 2− were watercourses, surface runoff, and phosphorus fertilizers. Both oxidized sulfur species (SO4 2−) and its reduced forms were found in sediments. Particular sulfur forms were characterized by large variations in both, concentrations and the isotopic composition of sulfur. SO4 2− in the sediment and in the water column had different genesis. Bacterial oxidation of organic sulfur and its binding in SO4 2− were observed in the sediment. Under reducing conditions, oxidized and organic sulfur is converted to H2S which reacted with Fe or other metallic ions leading to metal sulfide precipitation. Monosulfides were shown to have a very low concentration, ranging up to 0.07mg/g of sediment. The transformation of elemental sulfur from sulfides through their chemical oxidation occurred in the sediment.

      PubDate: 2017-01-27T18:42:47Z
       
  • X-ray computed tomography of planetary materials: A primer and review of
           recent studies
    • Abstract: Publication date: Available online 21 January 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Romy D. Hanna, Richard A. Ketcham
      X-ray computed tomography (XCT) is a powerful 3D imaging technique that has been used to investigate meteorites, mission-returned samples, and other planetary materials of all scales from dust particles to large rocks. With this technique, a 3D volume representing the X-ray attenuation (which is sensitive to composition and density) of the materials within an object is produced, allowing various components and textures to be observed and quantified. As with any analytical technique, a thorough understanding of the underlying physical principles, system components, and data acquisition parameters provides a strong foundation for the optimal acquisition and interpretation of the data. Here we present a technical overview of the physics of XCT, describe the major components of a typical laboratory-based XCT instrument, and provide a guide for how to optimize data collection for planetary materials using such systems. We also discuss data processing, visualization and analysis, including a discussion of common data artifacts and how to minimize them. We review a variety of recent studies in which XCT has been used to study extraterrestrial materials and/or to address fundamental problems in planetary science. We conclude with a short discussion of anticipated future directions of XCT technology and application.

      PubDate: 2017-01-27T18:42:47Z
       
  • Mineralogical characteristics of upper Jurassic Mikulov Marls, the Czech
           Republic, in relation to their thermal maturity
    • Abstract: Publication date: Available online 16 January 2017
      Source:Chemie der Erde - Geochemistry
      Author(s): Iva Sedláková, Eva Geršlová, Peter Uhlík, Vladimir Opletal
      The Upper Jurassic Marls of Mikulov present a formation that is considered to be the most promising strata to produce hydrocarbons in the Vienna basin. The marls are composed of dark pelagic marlstones that frequently contain layers of limestone with thickness reaching several hundreds of meters. Twenty-seven core samples from selected wells located in the south-eastern portion of the Czech Republic representing depths ranging from 2300 to 4500m were analyzed by x-ray diffraction to assess bulk mineralogy and the progress of smectite illitization. Bulk mineralogy of the Mikulov Marls comprises carbonates (mean value=54.4 mass%), clay minerals (26.6 mass%), quartz (15.0 mass%), and feldspar (1.6 mean%). In the decreasing order, the clay mineral fraction is composed of illite/mica, kaolinite, illite-smectite, and chlorite. The amount of smectite in illite-smectite decreases with depth from 70% to 28%. There is a change from random to ordered interstratification at the depth of 3300m. The transition from short-range ordering (R1) to long-range ordering (R3) occurs at depths greater than 4,500m. There was a good correspondence between thermal maturity parameters: the percentage of smectite in illite-smectite structures and vitrinite reflectance as a parameter of organic matter. The increase of the metamorphic grade was compared in respect to the geothermal gradient with adjacent basins.

      PubDate: 2017-01-20T17:34:12Z
       
 
 
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