Subjects -> EARTH SCIENCES (Total: 771 journals)
    - EARTH SCIENCES (527 journals)
    - GEOLOGY (94 journals)
    - GEOPHYSICS (33 journals)
    - HYDROLOGY (29 journals)
    - OCEANOGRAPHY (88 journals)

EARTH SCIENCES (527 journals)            First | 1 2 3     

Showing 201 - 371 of 371 Journals sorted alphabetically
Hydrological Processes     Hybrid Journal   (Followers: 44)
Hydrology and Earth System Sciences     Open Access   (Followers: 38)
ICES Journal of Marine Science: Journal du Conseil     Hybrid Journal   (Followers: 53)
IEEE Geoscience and Remote Sensing Letters     Hybrid Journal   (Followers: 150)
IEEE Geoscience and Remote Sensing Magazine     Hybrid Journal   (Followers: 6)
IEEE Journal of Oceanic Engineering     Hybrid Journal   (Followers: 11)
Indian Geotechnical Journal     Hybrid Journal   (Followers: 4)
Indonesian Journal on Geoscience     Open Access   (Followers: 1)
Inland Waters     Hybrid Journal  
Innovative Infrastructure Solutions     Hybrid Journal  
Interdisciplinary Environmental Review     Hybrid Journal   (Followers: 3)
International Geology Review     Hybrid Journal   (Followers: 17)
International Journal of Advanced Geosciences     Open Access   (Followers: 2)
International Journal of Advanced Remote Sensing and GIS     Open Access   (Followers: 50)
International Journal of Applied Earth Observation and Geoinformation     Open Access   (Followers: 36)
International Journal of Coal Geology     Hybrid Journal   (Followers: 2)
International Journal of Disaster Risk Reduction     Hybrid Journal   (Followers: 18)
International Journal of Earth Sciences     Hybrid Journal   (Followers: 37)
International Journal of Earthquake and Impact Engineering     Hybrid Journal   (Followers: 4)
International Journal of Energetic Materials     Full-text available via subscription  
International Journal of Environment and Geoinformatics     Open Access   (Followers: 4)
International Journal of Geo-Engineering     Open Access   (Followers: 2)
International Journal of Geographical Information Science     Hybrid Journal   (Followers: 55)
International Journal of Geomechanics     Full-text available via subscription   (Followers: 6)
International Journal of Geosciences     Open Access   (Followers: 10)
International Journal of Geosynthetics and Ground Engineering     Full-text available via subscription   (Followers: 3)
International Journal of Geotechnical Earthquake Engineering     Full-text available via subscription   (Followers: 9)
International Journal of Image and Data Fusion     Hybrid Journal   (Followers: 3)
International Journal of Remote Sensing     Hybrid Journal   (Followers: 144)
International Journal of Remote Sensing Applications     Open Access   (Followers: 49)
International Journal of Soil, Sediment and Water     Open Access   (Followers: 4)
International Journal of Speleology     Open Access   (Followers: 3)
Iraqi National Journal of Earth Sciences     Open Access  
iScience     Open Access   (Followers: 1)
Island Arc     Hybrid Journal   (Followers: 5)
ISPRS International Journal of Geo-Information     Open Access   (Followers: 5)
Italian Journal of Geosciences     Open Access  
Izvestiya, Atmospheric and Oceanic Physics     Full-text available via subscription   (Followers: 1)
Izvestiya, Physics of the Solid Earth     Hybrid Journal   (Followers: 2)
Jahresberichte und Mitteilungen des Oberrheinischen Geologischen Vereins     Full-text available via subscription   (Followers: 2)
JETP Letters     Hybrid Journal   (Followers: 3)
Journal of Earth Science & Climatic Change     Open Access   (Followers: 14)
Journal of Advances in Modeling Earth Systems     Open Access   (Followers: 5)
Journal of African Earth Sciences     Hybrid Journal   (Followers: 11)
Journal of Analytical and Numerical Methods in Mining Engineering     Open Access  
Journal of Applied Geophysics     Hybrid Journal   (Followers: 15)
Journal of Applied Volcanology     Open Access   (Followers: 7)
Journal of Arid Land     Hybrid Journal  
Journal of Asian Earth Sciences     Hybrid Journal   (Followers: 15)
Journal of Asian Earth Sciences : X     Open Access  
Journal of Atmospheric and Oceanic Technology     Hybrid Journal   (Followers: 33)
Journal of Atmospheric and Solar-Terrestrial Physics     Hybrid Journal   (Followers: 133)
Journal of Big History     Open Access   (Followers: 3)
Journal of Coastal Conservation     Hybrid Journal   (Followers: 6)
Journal of Coastal Research     Hybrid Journal   (Followers: 31)
Journal of Contemporary Physics (Armenian Academy of Sciences)     Hybrid Journal   (Followers: 9)
Journal of Contemporary Water Resource & Education     Hybrid Journal   (Followers: 2)
Journal of Earth Science     Hybrid Journal   (Followers: 12)
Journal of Earth System Science     Open Access   (Followers: 52)
Journal of Earth, Environment and Health Sciences     Open Access   (Followers: 2)
Journal of Earthquake and Tsunami     Hybrid Journal   (Followers: 2)
Journal of Earthquake Engineering     Hybrid Journal   (Followers: 14)
Journal of Environment and Earth Science     Open Access   (Followers: 11)
Journal of Environmental & Engineering Geophysics     Hybrid Journal   (Followers: 2)
Journal of Geodesy     Hybrid Journal   (Followers: 9)
Journal of Geodesy and Geoinformation     Open Access   (Followers: 2)
Journal of Geodynamics     Hybrid Journal   (Followers: 6)
Journal of Geography, Environment and Earth Science International     Open Access  
Journal of Geology     Full-text available via subscription   (Followers: 30)
Journal of Geomorphology     Open Access   (Followers: 3)
Journal of Geophysical Research : Atmospheres     Partially Free   (Followers: 134)
Journal of Geophysical Research : Biogeosciences     Full-text available via subscription   (Followers: 34)
Journal of Geophysical Research : Earth Surface     Partially Free   (Followers: 59)
Journal of Geophysical Research : Oceans     Partially Free   (Followers: 60)
Journal of Geophysical Research : Planets     Full-text available via subscription   (Followers: 115)
Journal of Geophysical Research : Solid Earth     Full-text available via subscription   (Followers: 57)
Journal of Geophysical Research : Space Physics     Full-text available via subscription   (Followers: 136)
Journal of Geophysics and Engineering     Hybrid Journal   (Followers: 2)
Journal of Geoscience Education     Hybrid Journal   (Followers: 1)
Journal of Geoscience, Engineering, Environment, and Technology     Open Access   (Followers: 1)
Journal of Geosciences     Open Access   (Followers: 5)
Journal of Geosciences and Geomatics     Open Access   (Followers: 1)
Journal of Geospatial Applications in Natural Resources     Open Access  
Journal of Geotechnical and Geoenvironmental Engineering     Full-text available via subscription   (Followers: 30)
Journal of Geotechnical Engineering     Full-text available via subscription   (Followers: 4)
Journal of Great Lakes Research     Hybrid Journal   (Followers: 5)
Journal of Hydro-environment Research     Full-text available via subscription   (Followers: 13)
Journal of Hydrologic Engineering     Full-text available via subscription   (Followers: 40)
Journal of International Maritime Safety, Environmental Affairs, and Shipping     Open Access   (Followers: 1)
Journal of Life and Earth Science     Open Access  
Journal of Marine Medical Society     Open Access   (Followers: 1)
Journal of Marine Research     Full-text available via subscription   (Followers: 20)
Journal of Marine Science and Technology     Hybrid Journal   (Followers: 3)
Journal of Marine Systems     Hybrid Journal   (Followers: 9)
Journal of Metamorphic Geology     Hybrid Journal   (Followers: 15)
Journal of Mining Science     Hybrid Journal   (Followers: 2)
Journal of Mountain Science     Hybrid Journal  
Journal of Natural Gas Geoscience     Open Access  
Journal of Ocean and Climate     Open Access   (Followers: 9)
Journal of Oceanology and Limnology     Hybrid Journal   (Followers: 3)
Journal of Petroleum Exploration and Production Technology     Open Access   (Followers: 2)
Journal of Petroleum Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Petrology     Hybrid Journal   (Followers: 11)
Journal of Plasma Physics     Hybrid Journal   (Followers: 21)
Journal of Population and Sustainability     Open Access  
Journal of Quaternary Science     Hybrid Journal   (Followers: 31)
Journal of Rock Mechanics and Geotechnical Engineering     Open Access   (Followers: 3)
Journal of Sea Research     Hybrid Journal   (Followers: 6)
Journal of Sedimentary Environments     Open Access  
Journal of Seismology     Hybrid Journal   (Followers: 9)
Journal of Spatial Information Science     Open Access   (Followers: 4)
Journal of Structural Geology     Hybrid Journal   (Followers: 26)
Journal of Systematic Palaeontology     Hybrid Journal   (Followers: 7)
Journal of the Atmospheric Sciences     Hybrid Journal   (Followers: 83)
Journal of the Geological Society     Hybrid Journal   (Followers: 17)
Journal of the Royal Society of New Zealand     Hybrid Journal   (Followers: 48)
Journal of the World Aquaculture Society     Hybrid Journal   (Followers: 13)
Journal of Volcanology and Geothermal Research     Hybrid Journal   (Followers: 17)
Journal of Water and Climate Change     Open Access   (Followers: 52)
Journal on Geoinformatics, Nepal     Open Access   (Followers: 1)
Jurnal Ilmiah Perikanan dan Kelautan / Scientific Journal of Fisheries and Marine     Open Access  
Kartografija i geoinformacije (Cartography and Geoinformation)     Open Access  
Lake and Reservoir Management     Hybrid Journal   (Followers: 7)
Landslides     Hybrid Journal   (Followers: 26)
Latin American Journal of Sedimentology and Basin Analysis     Open Access   (Followers: 1)
Lethaia     Hybrid Journal   (Followers: 5)
Letters in Mathematical Physics     Hybrid Journal   (Followers: 4)
Limnologica     Hybrid Journal   (Followers: 4)
Limnology     Hybrid Journal   (Followers: 9)
Lithology and Mineral Resources     Hybrid Journal   (Followers: 3)
Lithos     Hybrid Journal   (Followers: 9)
Malaysian Journal of Geosciences     Open Access  
Marine and Freshwater Research     Hybrid Journal   (Followers: 6)
Marine and Petroleum Geology     Hybrid Journal   (Followers: 21)
Marine Biology Research: New for 2005     Hybrid Journal   (Followers: 2)
Marine Economics and Management     Open Access   (Followers: 4)
Marine Environmental Research     Hybrid Journal   (Followers: 31)
Marine Geodesy     Hybrid Journal   (Followers: 4)
Marine Geology     Hybrid Journal   (Followers: 31)
Marine Geophysical Researches     Hybrid Journal   (Followers: 5)
Marine Georesources & Geotechnology     Hybrid Journal  
Marine Mammal Science     Hybrid Journal   (Followers: 10)
Marine Policy     Hybrid Journal   (Followers: 60)
Mathematical Geosciences     Hybrid Journal   (Followers: 4)
Mathematical Physics, Analysis and Geometry     Hybrid Journal   (Followers: 3)
Mediterranean Geoscience Reviews     Hybrid Journal  
Meteoritics & Planetary Science     Hybrid Journal   (Followers: 18)
Meteorologische Zeitschrift     Full-text available via subscription   (Followers: 4)
Mineralium Deposita     Hybrid Journal   (Followers: 4)
Mineralogia     Open Access   (Followers: 2)
Mineralogy and Petrology     Hybrid Journal   (Followers: 2)
Mineria y Geologia     Open Access  
Mining, Metallurgy & Exploration     Hybrid Journal  
Momona Ethiopian Journal of Science     Open Access   (Followers: 5)
Mongolian Geoscientist     Open Access  
Moscow University Geology Bulletin     Hybrid Journal  
Moscow University Physics Bulletin     Hybrid Journal  
Natural Hazards     Hybrid Journal   (Followers: 53)
Natural Hazards and Earth System Sciences (NHESS)     Open Access   (Followers: 10)
Natural Hazards and Earth System Sciences Discssions     Open Access  
Natural Hazards Research     Open Access  
Natural Hazards Review     Full-text available via subscription   (Followers: 16)
Natural Resources & Engineering     Hybrid Journal  
Natural Resources Research     Hybrid Journal   (Followers: 8)
Nature Geoscience     Full-text available via subscription   (Followers: 161)
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen     Full-text available via subscription   (Followers: 3)
Neues Jahrbuch für Mineralogie - Abhandlungen     Full-text available via subscription   (Followers: 1)
Newsletters on Stratigraphy     Full-text available via subscription   (Followers: 2)
Nonlinear Processes in Geophysics (NPG)     Open Access  
Nonlinear Processes in Geophysics Discussions     Open Access  
Ocean & Coastal Management     Hybrid Journal   (Followers: 62)
Ocean Development & International Law     Hybrid Journal   (Followers: 15)
Ocean Dynamics     Hybrid Journal   (Followers: 6)
Ocean Engineering     Hybrid Journal   (Followers: 6)
Ocean Modelling     Hybrid Journal   (Followers: 12)
Ocean Science (OS)     Open Access   (Followers: 7)
Ocean Science Journal     Hybrid Journal   (Followers: 6)
Open Geospatial Data, Software and Standards     Open Access   (Followers: 3)
Open Journal of Earthquake Research     Open Access   (Followers: 3)
Open Journal of Soil Science     Open Access   (Followers: 9)
Ore and Energy Resource Geology     Open Access  
Ore Geology Reviews     Hybrid Journal   (Followers: 11)
Organic Geochemistry     Hybrid Journal   (Followers: 4)
Osterreichische Wasser- und Abfallwirtschaft     Hybrid Journal  
Paläontologische Zeitschrift     Hybrid Journal   (Followers: 4)
Papers in Palaeontology     Hybrid Journal  
Permafrost and Periglacial Processes     Hybrid Journal   (Followers: 5)
Perspectives of Earth and Space Scientists i     Open Access   (Followers: 1)
Petroleum Geoscience     Hybrid Journal   (Followers: 5)
Petroleum Science     Open Access  
Petrology     Full-text available via subscription   (Followers: 6)
PFG : Journal of Photogrammetry, Remote Sensing and Geoinformation Science     Hybrid Journal   (Followers: 4)
Photogrammetrie - Fernerkundung - Geoinformation     Full-text available via subscription  
Physical Geography     Hybrid Journal   (Followers: 8)
Physical Science International Journal     Open Access  
Physics of Life Reviews     Hybrid Journal   (Followers: 1)
Physics of Metals and Metallography     Hybrid Journal   (Followers: 18)
Physics of Plasmas     Hybrid Journal   (Followers: 10)
Physics of the Earth and Planetary Interiors     Hybrid Journal   (Followers: 34)
Physics of the Solid State     Hybrid Journal   (Followers: 7)

  First | 1 2 3     

Similar Journals
Journal Cover
Journal of Earth Science
Journal Prestige (SJR): 0.604
Citation Impact (citeScore): 1
Number of Followers: 12  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1674-487X - ISSN (Online) 1867-111X
Published by Springer-Verlag Homepage  [2469 journals]
  • Thermal Conductivity and Thermal Diffusivity of Ferrosilite under High
           Temperature and High Pressure

    • Free pre-print version: Loading...

      Abstract: Abstract Orthopyroxene is an important constitutive mineral in the crust and the upper mantle. Its thermal properties play a key role in constructing the thermal structure of the crust and the upper mantle. In this study, we developed a new method to synthesize polycrystalline ferrosilite, one end-member of orthopyroxene, via the reaction of FeO + SiO2 → FeSiO3. We found that the P-T condition of 3 GPa and 1 273 K is suitable to synthesize dense ferrosilite samples with low porosity. We employed the transient plane-source method to investigate the thermal conductivity κ and thermal diffusivity D of synthetic ferrosilite at 1 GPa and 293–873 K, of which, κ = 1.786 + 1.048 × 103T−1–9.269 × 104T−2 and D = 0.424 + 0.223 × 103T−1 + 1.64 × 104T−2. Our results suggest phonon conduction should be the dominant mechanism at P-T conditions of interest since the thermal conductivity and the thermal diffusivity of ferrosilite both decrease with increasing temperature. The calculated heat capacity of ferrosilite at 1 GPa increases with temperature, which increases with increasing temperature with about 10% per 100 K (<500 K) and 4% per 100 K (>500 K). Iron content of an asteroid significantly influences its thermal evolution history and temperature distribution inside. It is expected that the mantle temperature of the Fe-rich asteroid will be higher and the Fe-rich asteroid’s cooling history will be longer.
      PubDate: 2022-04-07
       
  • Theoretical System of Sandstone-Type Uranium Deposits in Northern China

    • Free pre-print version: Loading...

      Abstract: Abstract Many theoretical results on sandstone-type uranium mineralization in northern China obtained by the uranium research team of the Tianjin Center of Geological Survey in recent years are presented. From the source sink system of uranium-producing basins, sedimentary environment of uranium-bearing rock series, ore-forming fluid information, evolution of tectonic events, basin formation and development, we redefine and classify uranium orebodies, redox zoning, and ore-controlling structural styles. We then systematically propose a theoretical system of sandstone-type uranium deposits in northern China. We conclude that sandstone-type uranium deposits in northern China are mainly found in sedimentary environments such as rivers, deltas, and alluvial fans in the Mesozoic and Cenozoic lowstand systems tract and in gray sandstone layers in the vertical redox zoning. The orebodies are controlled by the tectonic slope belt, which is in the shape of a strip on the plane, and spreads in a layer or plate on the section. Vertical (ups and downs) tectonic movement triggers large-scale phreatic flow in the basin, which is the real driving force for controlling the ore-forming fluid. The theoretical system of sandstone-type uranium deposits in northern China should be based on global tectonic movement and environmental changes and take into account factors such as basins as a unit to study mineralization background, ore concentration areas as objects to study mineralization, and the correlation between regional tectonic movement and metallogenic process as a breakthrough point to study tectonic events and metallogenic events. It should also be based on different basin types to establish metallogenic models. The innovative research results and ideas are summarized with the aim of promoting the continuous improvement of sandstone-type uranium mineralization theory in northern China.
      PubDate: 2022-04-01
       
  • Characteristics of Altered Ilmenite in Uranium-Bearing Sandstone and Its
           Relationship with Uranium Minerals in the Northeastern Ordos Basin

    • Free pre-print version: Loading...

      Abstract: Abstract In recent years, the close relationship between uranium and Ti-Fe oxides in the sandstone-type uranium deposits has been extensively recognized. However, the altered characteristics of ilmenite and its relationship with uranium enrichment still remain unclear. With this paper based on heavy-mineral sorting of uranium ore selected from the Tarangaole-Nalinggou deposit in the northeastern Ordos Basin, electron probe, backscattering image, energy spectrum and scanning electron microscopy were systematically performed. The ilmenite in the sandstone can be divided into four groups, including unaltered, weakly altered, moderately altered, and strongly altered ilmenite. The alteration of ilmenite in uranium ores is notably more intense than that of the surrounding rocks. In addition, weakly, moderately, and strongly altered ilmenite associated with uranium minerals in uranium ores demonstrate that the more intensity ilmenite altered, the closer its relationship with uranium minerals is. The ilmenite has likely been somewhat altered before mineralization, and the alteration intensifies by later exposure related to an oxygen-containing fluid. The alteration mechanism comprises a process of competitive diffusion between Fe2+ and O2− ions. In the early stage, Fe ions was mainly diffused on the particle surface. Subsequently, diffusion of O ions into the particles began to be dominate. Most of the leached iron is stripped or carried away by fluid. In an alkaline and reductive environment, the remaining iron is reduced to form the surrounding pyrite, and TiO2 in a form of titanium sol recrystallizes (i.e., anatase). Backscattering images show that uranium and altered ilmenite are close in space. Coffinite is often distributed along the edges of altered ilmenite as burrs in shape. Colloidal or knitted coffinite associated with anatase is formed in the voids of altered ilmenite. The chemical composition of altered ilmenite varies considerably from the core to edge, and the mineral assemblage sequence is from girdle with ilmenite, to leucosphenite, to anatase, and to coffinite. There is no brannerite that is symbiotic with altered ilmenite. It is considered to be a uranium-containing titanium mineral aggregate caused by the reduction and adsorption of uranium. As the altered product of ilmenite, TiO2 is an aggregation agent, increasing the concentration of uranium by adsorption. Together with Fe2+ and S2− in secondary pyrite, this aggregate creates a uranium-rich environment in the microzone for the formation of coffinite. Therefore, the alteration of ilmenite plays a geochemical role in the processes of sedimentary, diagenesis and mineralization, in which Fe is removed, Ti is enriched, and U is adsorbed and reduced.
      PubDate: 2022-04-01
       
  • Relations of Uranium Enrichment and Metal Sulfides within the Shuanglong
           Uranium Deposit, Southern Ordos Basin

    • Free pre-print version: Loading...

      Abstract: Abstract Large quantities of metal sulfides are widely distributed in uranium ores from the Middle Jurassic Zhiluo Formation of the Shuanglong uranium deposit, southern Ordos Basin, providing a convenient condition to study the relationship between metal sulfides and uranium minerals. The morphology and composition of uranium minerals and metal sulfides are illustrated to study uranium mineralization and mechanisms of metallogenesis. Uranium minerals can be broadly categorized as pitchblende, coffinite and brannerite. Metal sulfides associated with uranium minerals are pyrite, sphalerite, chalcopyrite and galena. Some assemblages of various metal sulfides and uranium minerals indicate that they are coeval, but the order of formation is different. Based on mineralogical observations, paragenetic sequences for mineral assemblages are discussed. Alteration of Fe-Ti oxides forms Ti oxides, brannerite and pyrite. The formation of chalcopyrite was later than that of pyrite. Clausthalite (PbSe) replaces sphalerite or shows isomorphism with galena. There are three genetic types of galena, of which type I is related to tectonic thermal events and can interact with uranyl ions to form uranium oxides and Pb2+. When sulfur activity is relatively high, Pb2+ can form new anhedral galena, that is, type II. Type III of galena is related to the decay of uranium minerals. The genetic order of the main minerals was determined as follows: Fe-Ti oxides>Ti oxides/sphalerite/pyrite>clausthalite/galena I/chalcopyrite>galena I /uranium minerals>galena m during the diagenetic stage. Hydrogen sulfide (H2S) is a decisive factor in the interaction between metal sulfides and uranium. Metal ions can react with H2S, accompanied by precipitation and enrichment of uranium minerals.
      PubDate: 2022-04-01
       
  • Crystallization of Hydrous Ti-Rich Basaltic Magma and Its Implication for
           the Origin of Fe−Ti Oxide in Layered Intrusions of the Emeishan Large
           Igneous Province

    • Free pre-print version: Loading...

      Abstract: Abstract A series of crystallization experiments have been carried out by using natural Emeishan Ti-rich hydrous basalts as starting materials at a pressure of 0.5 GPa and temperatures of 800–1 000 °C to constrain the origin of Fe−Ti−V oxide ore deposits. Our experimental results demonstrate that the sandwich- and trellis-type ilmenite lamellae in titanomagnetite of layered intrusions can be formed by the reaction of earlier crystallized ilmenite and the evolved parental magma. During evolution of parental basaltic magma, the Fe−Ti oxide should be composed of titanomagnetite+ilmenite in the earlier stage, but changed to titanomagnetite+titanomagnetite-ilmenite intergrowth±ilmenite at the later stage. Accordingly, the Panzhihua Fe−Ti oxide ores, which are mainly composed of titanomagnetite, should be formed earlier than the adjacent gabbro, in which titanomagnetite-ilmenite intergrowth is the major form of the Fe-Ti oxide.
      PubDate: 2022-04-01
       
  • Central Asia—A Global Model for the Formation of Epigenetic Deposits in
           a Platform Sedimentary Cover

    • Free pre-print version: Loading...

      Abstract: Abstract Metallogenic specialization of sedimentary cover in Central Asia is determined by its tectonic setting that governs the hydrodynamic regime (exfiltrational or infiltrational) and as a consequence, the hydrogeochemical zonality (type of water and its gaseous and microcomponent composition). Hydrodynamic conditions (distribution of recharge and discharge areas) determine the direction of stratal water flow and location of mineralization resulted from the change in geochemical, thermodynamic, lithological, structural and other conditions. The exfiltrational regime suggests a dependence of the epigenetic mineralization upon the distribution and degree of preservation of hydrocarbon occurrences. Often, hydrocarbon matter serves as a reducing barrier and ore-concentrating factor during the formation of polymineral concentrations related to stratal oxidation zone. The supergene epigenetic ore-forming processes are induced by the interaction between the Earth’s sedimentary cover and hydrosphere. Sedimentary rocks themselves commonly serve as a source of ore materials. The ore deposition zones on geochemical barriers and ore material source are often located significantly apart from each other. The trend of these processes is determined by the position of ore-bearing depressions in large tectonic blocks.
      PubDate: 2022-04-01
       
  • Déjà vu: Might Future Eruptions of Hunga Tonga-Hunga Ha’apai Volcano
           be a Repeat of the Devastating Eruption of Santorini, Greece (1650
           BC)'

    • Free pre-print version: Loading...

      PubDate: 2022-04-01
       
  • Provenance of Late Mesozoic Strata and Tectonic Implications for the
           Southwestern Ordos Basin, North China: Evidence from Detrital Zircon
           U−Pb Geochronology and Hf Isotopes

    • Free pre-print version: Loading...

      Abstract: Abstract In order to determine the provenance and variation characteristics of sandstone-type uranium deposits located in the southwest Ordos Basin, U−Pb geochronology and Hf isotope analyses were conducted on detrital zircons from the Late Mesozoic strata of the SD01 well in the Zhenyuan area. The detrital zircon U−Pb ages of four samples exhibited four main peaks at 250–330, 420–500, 1 720–2 000, and 2 340–2 580 Ma, with a small number of zircons dated at 770–1 100 Ma. The detrital zircon age spectrum and further restriction provided by the in-situ Hf isotopic data suggest that the provenance of each stratum was mainly derived from the crystalline basement rock series (Khondalites, intermediate-acidic intrusive rocks, and metamorphic rocks) of the Alxa Block to the northwest and the Yinshan Block to the north, with minor amounts of Caledonian magmatic rocks and Jingning Period rocks from the western part of the northern Qilian orogenic belt to the west and the northern Qinling orogenic belt to the south. The provenance of the sandbody has not changed significantly and is of the Middle Jurassic-Early Cretaceous. The clear variations in the zircon ages of the samples from the Zhiluo and Anding formations were likely influenced by climate change during the Middle-Late Jurassic. The Triassic zircon age (<250 Ma) first appeared in Early Cretaceous strata, suggesting that tectonic activity was relatively strong in the northern Qinling orogenic belt during the Late Jurassic and produced extensive outcrops of Indo-Chinese granite, which were a source of basin sediments.
      PubDate: 2022-04-01
       
  • Deformation Kinematics of Main Central Thrust Zone (MCTZ) in the Western
           Himalayas

    • Free pre-print version: Loading...

      Abstract: Abstract The main central thrust (MCT) is one of the major thrusts in Himalayas. In central Himalaya, MCT was defined as a contact between underlying Lesser Himalayan Sequence (LHS) and overlying higher Himalayan crystallines (HHC). However, in the Kashmir Himalayas, the main central thrust zone (MCTZ), shear zone associated with MCT, is overlain by Kashmir Tethyan Sequence suggesting that the MCTZ has been deformed through a mechanism different than the mechanism responsible for MCTZ evolution in other parts of the Himalayas. In the present study we used structural, microfabric and kinematic analyses to investigate the deformation kinematics of MCTZ. Microstructural investigation revealed that the quartz in orthogneiss mylonites of MCTZ was dynamically recrystallized by grain boundary migration (GBM) and sub-grain rotation recrystallisation (SGR) with top-to-SW sense of shear. The mean kinematic vorticity number (Wm) just above the thrust ranges from 0.72 to 0.84 (40%–52% pure shear component) decreasing upwards to 0.65–0.71 (35%–50% pure shear component). Deformation in the MCTZ is characterized by Rxz strain ratio varying from 2.7 to 8. The present study suggested that the MCTZ suffered 3%–40% vertical shortening and 3%–66% transport-parallel elongation. The results suggested that the HHC’s were not completely exhumed to the topographic surfaces in the Kashmir Himalayas. Along the basal decollement, i. e., the main Himalayan thrust (MHT), the deformation continued until MCTZ reached the brittle-ductile transition where deformation mechanism changed to the brittle and the MCTZ rocks were transported to the surface through slip on brittle MCT.
      PubDate: 2022-04-01
       
  • Metamorphic Evolution of a Tremolite Marble from the Dabie UHP Terrane,
           China: A Focus on Zircon

    • Free pre-print version: Loading...

      Abstract: Abstract In this study, a tremolite marble from the Dabie ultrahigh-pressure (UHP) terrane, east-central China was investigated for its metamorphic evolution by focusing on zircon. The marble contains an amphibolite-facies assemblage of dolomite, Mg-calcite, tremolite, biotite, and plagioclase, while zircon in the marble witnesses a complex recrystallization and growth history under both amphibolite-and eclogite-facies conditions. Cathodoluminescence reveals eight characteristic zones for zircon. As indicated by mineral inclusions in zircon, two zones formed no earlier than amphibolite-facies retrogression and are too thin to date. The other six zones contain inclusions of dolomite, aragonite, diopside (XNa=Na/(Na+Ca)=0.11–0.14), garnet (XCa=0.51–0.62, XMg=0.21–0.23, XFe=0.17–0.26, XMn=0.01), phengite and rutile, and formed under eclogite-facies conditions. Phase equilibria calculations illustrat that the Na-richest diopside formed under UHP conditions. Being an accessory eclogite-facies mineral in the marble, the analyzed chemistry of garnet inclusions cannot be reproduced by phase equilibria calculations because solid-solution models for many other minerals don’t incorporate Mn-endmembers. The eclogite-facies zircon zones show low HREE contents and flat MREE-HREE distribution patterns, which are interpreted to have been determined by the low bulk-rock HREE content instead of the presence of accessary garnet in the marble. U-Pb dating yielded a large age dataset ranging from about 250 to 210 Ma for the eclogite-facies zircon zones. Statistically, the eclogite-facies ages are characterized by a Gaussian distribution with a median peak at 232 Ma. We propose that zircon experienced a “protracted” recrystallization and/or growth history in the tremolite marble during the Triassic subduction and exhumation.
      PubDate: 2022-04-01
       
  • Biostratigraphy of Albian Sediments (Kazhdumi Formation) in Zagros Area
           (Southwest of Iran)

    • Free pre-print version: Loading...

      Abstract: Abstract To investigate biostratigraphy of Albian sediments (Kazhdumi Formation) in the Zagros Basin, 280 samples in four sections were prepared which are nominated as Murshan-e-Bala, Fahliyan-e-Pain, Kupon and Tale-e-Afghani. Stratigraphic distribution of identified foraminifers confirms well developed orbitolinids which are associated with other Albian benthic foraminifers in all studied sections. The orbitolinids are recognized in surrounding strata [Dariyan (at the base which is marked by an oxidized zone) and Sarvak Formations (on the top, as gradtional contact)] as well as the Kazhdumi Formation. Obtained biostratigraphic data show that Early Albian is marked by the presence of Hemicyclammina sigali, which co-occurs with Mesorbitolina texana and Mesorbitolina subconcava, whereas Conicorbitolina conica and Meorbitolina parva support Late Albian age of the studied sections. Calcareous algae are associated with both benthic faunal assemblages. Albian planktons occur in the studied sections which are identified as Favusella washitensis and Calcisphaerula inomminata subzones. The stratigraphic position of planktons actually indicates vertical displacement in the sedimentary basin during Albian time. Other associated Albian pelagic foraminifera are identified which are obviously recognized in three sections of the Kazhdumi Formation. The presence of pelagic species in the study section of the Kazhdumi Formation indicates basement faulting during the Albian period.
      PubDate: 2022-04-01
       
  • Uranium Metallogeny in Fault-Depression Transition Region: A Case Study of
           the Tamusu Uranium Deposit in the Bayingobi Basin

    • Free pre-print version: Loading...

      Abstract: Abstract Compared to the sandstone-type uranium deposits in the Ordos Basin and the Songliao Basin, the Tamusu uranium deposit in the Bayingobi Basin formed in fault-depression transition region displays distinctive features. First, the uranium-bearing sandstones and their interlayer oxidation zone extend longitudinally no more than ten kilometers. Second, gravity flow sediments are more common in the uranium-bearing strata. Comprehensive facies analysis indicates that the Upper Member (ore-bearing horizon) of the Bayingobi Formation was largely deposited in fan deltas that prograded into lakes during period of relatively dry paleoclimate. Spatial distribution patterns of five facies associations along with two depositional environments (fan delta, lake) were reconstructed in this study. The results demonstrated that the depositional systems and their inner genetic facies played different roles in uranium reservoir sandstone, confining beds (isolated barrier beds) and reduction geologic bodies during uranium mineralization process.
      PubDate: 2022-04-01
       
  • Impact of Particle Crush-Size and Weight on Rock-Eval S2, S4, and Kinetics
           of Shales

    • Free pre-print version: Loading...

      Abstract: Abstract The Rock-Eval technique in the last few decades has found extensive application for source rock analysis. The impact of shale particle crush-size and sample weight on key Rock-Eval measurements, viz. the S2 curve (heavier hydrocarbons released during the non-isothermal pyrolysis-stage) and the S4 curve (CO2 released from oxidation of organic matter during the oxidation-stage) are investigated in this study. For high and low total organic carbon (TOC) samples of different thermal maturity levels, it is apparent that particle crush-size has a strong influence on the results obtained from Rock-Eval analysis, with the effect being stronger in high-TOC samples. In comparison to the coarser-splits, S2 and pyrolyzable carbon (PC) were found to be higher for the finer crush sizes in all the shales studied. The S4CO2 oxidation curve shapes of Permian shales show contrasting signatures in comparison to the Paleocene-aged lignitic shale, both from Indian basins. A reduced TOC was observed with rising sample weight for a mature Permian shale from the Jharia basin, while the other shales sampled showed no significant reduction. The results indicate that the S4CO2 curve and the S4Tpeak, are strongly dependent on the type of organic-matter present and its level of thermal maturity. Sample weight and particle size both influence the S2-curve shapes at different heating rates. With increasing sample weights, an increase in S2-curve magnitude was observed for the shales of diverse maturities. These differences in the S2 curve shape lead to substantially different kinetic distributions being fitted to these curves. These findings are considered to have significant implications for the accuracy of reaction kinetics obtained from pyrolysis experiments using different sample characteristics.
      PubDate: 2022-04-01
       
  • U-Blacks Mineralization in Sandstone Uranium Deposits

    • Free pre-print version: Loading...

      Abstract: Abstract Ores of infiltration sandstone-hosted uranium deposits in the sedimentary cover are ubiquitous composed of dispersed soot powder mineralization of black, brownish-black colour. Long-term studies of such loose U-ores by analytical transmission electron microscopy (ATEM) proved their polymineral nature. Uranium blacks are composed by at least three different U-mineral forms: oxide (uraninite), silicate (coffinite) and phosphate (ningyoite) which are present in various proportions of ore compositions. Such high dispersed friable uranium formations are difficult to diagnose by traditional mineralogical methods (optical, XRD, IR and X-ray spectroscopy, etc.) which analyze total sample composition (phases mixture); their results characterize the dominant sample phase, omitting both sharply subordinate and X-ray amorphous phases. All research results are based on ATEM methods (SAED+EDS), which are optimal for crystallochemical diagnostics in the mineralogical study of such uranium ores. The article presents the diagnostic characteristics under electron microscope (EM) of uranous minerals from different sandstone deposits with their origin being discussed.
      PubDate: 2022-04-01
       
  • Formation Mechanism of Ground Fissures Originated from the Hanging Wall of
           Normal Fault: A Case in Fen-Wei Basin, China

    • Free pre-print version: Loading...

      Abstract: Abstract This paper takes Fen-Wei Basin (FWB) as a case to study the ground fissures controlled by normal fault. Based on the field investigation, geophysical exploration, drilling, GNSS data and numerical calculation, the characteristics and mechanism of ground fissures originated from the hanging wall of normal faults are revealed. The results show that the distribution of ground fissures in the hanging wall and heading wall of the active faults is not uniform. Ground fissures are mostly distributed in the hanging wall of active faults and show a linear distribution on the surface, their strike is consistent with the fault, mainly characterized by vertical offset and horizontal tension. Ground fissures destroy the farmland and building foundation through which they pass and cause the rupture or displacement. In profile section, the ground fissure shows the characteristics of normal faults and dislocates the strata, and is connected with the underlying faults. Numerical analysis shows that the vertical displacement of normal fault activity in hanging wall is much larger than that in heading wall, which is the reason that tectonic ground fissures mainly originate from hanging wall. The range of dangerous area of ground fissures is controlled by the depth of fault, the strength of the ground fissures disaster is mainly controlled by the activity of fault. The formation of the ground fissures originated from the hanging wall of the fault experienced three stages: the main fault activity stage, the secondary fault activity stage and the fissure formation stage.
      PubDate: 2022-04-01
       
  • Origin of Dispersed Organic Matter within Sandstones and Its Implication
           for Uranium Mineralization: A Case Study from Dongsheng Uranium Ore Filed
           in China

    • Free pre-print version: Loading...

      Abstract: Abstract Carbonaceous debris (CD), common dispersed organic matter (i.e., DOM), is widely disseminated in sandstones from uranium-bearing strata from the Dongsheng uranium ore field of the northern Ordos Basin. Compositions of maceral, element and biomarkers of CD were investigated through a series of methods with optical microscope, elemental analyzer and gas chromatography-mass spectrometry analyses (GC-MS) to study origin of CD. The results show that CD, centrally distributed nearby channel erosion surface, decreases with the increased distances to channel erosion surface, which indicates the CD might be related to the coal seam from the upper unit of the J2y Formation or synsedimentary plant from the J2z Formation. Macerals of CD are composed of vitrinite (i.e., V), inertinite (i.e., I), and minerals, including that V is primary. Compared with the coals from the J2y Formation classed into vitrinertite-V (V+I>95%, V>I), CD is grouped into vitrite (V>95%). Although, CD and coal are similar in element composition, the former is of lower organic carbon, H, N, and higher S. The (C27+C29)/(C31+C33) ratios of n-alkanes biomarkers indicate that the percentage of woody plants accounting for vegetation composition of CD predominate over that of coal, which is also evidenced by the higher C/N ratios and oleanane contents of CD. The evidence is also supported by plant branch buried in sandstones. The distribution characteristics of CD and differences in vegetation types between CD and coal suggest that CD might be not from the coal seam from J2y. The tissue preservation index, gelification index, ground water level index, and vegetation index reflect that the paleoenvironment of CD is controlled by fluctuating water, which is also supported by the existences of round CD. Compared with peat, sedimentary paleoenvironment where CD deposits is of weaker reducibility, higher salinity by analyzing Pr/Ph ratios and gammacerane index. Distributions of n-alkanes carbon number of CD with the presence of unknown complex mixtures show that microbial activities exist in sand bodies. Differences in hydrodynamic intensity, redox condition, and microbial activity intensity between sedimentary paleoenvironment of CD and peat, show that CD is born in synsedimentary sandstone environment not in peat. Hence, it comprehensively draws conclusions that immature ‘non-peatborn’ CD is formed from the trunk, stem, branch, root fragments buried in sandstones, depositing in (micro) allochthonous positions by the influences of fluctuating water. The DOM from synsedimentary plant debris might play more roles in adsorption and complexation, and microorganisms may participate in uranium mineralization, which could provide certain guidance for uranium exploration and mining.
      PubDate: 2022-04-01
       
  • Uranium Isotope Variations (234U/238U and 238U/235U) and Behavior of
           U−Pb Isotope System in the Vershinnoe Sandstone-Type Uranium Deposit,
           Vitim Uranium Ore District, Russia

    • Free pre-print version: Loading...

      Abstract: Abstract The U-Pb isotope system and uranium isotope composition (235U/238U and 234U/238U) were studied in a number of samples from the vertical section of the uranium ore body at the Vershinnoe sandstone-type deposit, Vitim uranium ore district, Russia. These parameters were determined to broadly vary. Deviations of the 234U/238U ratio from the equilibrium value indicate that the uranium ore was not completely conserved during the postore stage, and uranium was determined to continue migrating at the deposit. Comparison of the U−Pb isotope age value and 234U/238U isotope ratio provides an insight into the migrate direction of uranium in the ore body. The broad variations (137.377–137.772) in the 238U/235U ratio over the vertical section of the ore body can be explained by the different settings of the samples relative to the ore deposition front and changes in the redox conditions when this front shifted. The fact that the δ238U and K234/238 values are correlated indicates that the transfer of the 234U isotope into the aqueous phase may have been coupled with isotope fractionation in the 238U−235U system during the postformation uranium migration within the orebody.
      PubDate: 2022-04-01
       
  • Association of Sandstone-Type Uranium Mineralization in the Northern China
           with Tectonic Movements and Hydrocarbons

    • Free pre-print version: Loading...

      Abstract: Abstract In the continental basins of Northern China (NC), a series of energy resources commonly co-exist in the same basin. As the three typical superimposed basins of different genesis in the NC, the Junggar, Ordos, and Songliao basins were chosen as the research objects. The favorable uranium-bearing structures are generally shown as a basin-margin slope or transition belt of uplifts with the development of faults, which are conducive to a fluid circulation system. The Hercynian, Indosinian, and Yanshanian movements resulted in the development of uranium-rich intrusions which acted as the significant uranium sources. The main hydrocarbon source rocks are developed in the Carboniferous, Permian, Jurassic and Cretaceous. The mature stage of source rocks is concentrated in the Jurassic—Cretaceous, followed by the multi-stage expulsion events. Influenced by the India-Eurasian collision and the subduction of the Pacific Plate, the tectonic transformation in the Late Yanshanian and Himalayan periods significantly influenced the sandstone-type uranium mineralization. The hydrocarbon reservoirs are spatially consistent with sandstone-type uranium deposits, while the hydrocarbon expulsion events occur in sequence with sandstone-type uranium mineralization. In the periphery of the faults or the uplifts, both fluids met and formed uranium concentration. The regional tectonic movements motivate the migration of hydrocarbon fluids and uranium mineralization, especially the Himalayan movement.
      PubDate: 2022-04-01
       
  • WANCE: A possibly Volcanism-Induced Ediacaran Carbon Isotope Excursion

    • Free pre-print version: Loading...

      Abstract: Abstract Four carbonate carbon isotope (δ13Ccarb) excursions are recognized in the Ediacaran Doushantuo Formation in South China, the genesis of which remains disputed. Whereas three of these δ13Ccarb excursions possibly record secular biogeochemical variations, the other one, namely Weng’an negative carbonate carbon isotope excursion (WANCE) with an age of ca. 620 Ma occurs mainly within the northern Yangtze Platform. In this study, a SIMS U-Pb age of ca. 620 Ma was documented from continental rift volcanism within the adjacent South Qinling terrane. Its temporal overlap with WANCE suggests a possible causal link. Volcanism-induced seafloor uplift may have prompted DOC oxidation in surficial oxygenated oceans, inducing the occurrence of WANCE.
      PubDate: 2022-04-01
       
  • A Synthesis of Geophysical Data in Southeastern North China Craton:
           Implications for the Formation of the Arcuate Xuhuai Thrust Belt

    • Free pre-print version: Loading...

      Abstract: Abstract The Xuhuai fold thrust belt (XHTB) is a curved structure in the southeastern margin of the North China Craton (NCC) that has attracted great attentions due to its tectonic and petrological characteristics. However, few geophysical studies have focused on the deep structure of this belt. In this study, we carry out a systematic demonstration of the main geophysical features that characterize the XHTB and surrounding areas. The results reveal small negative gravity and magnetic anomalies, thin crust and lithosphere, lower shear velocity and shallower earthquake epicenters relative to other areas of the NCC, collectively indicating a lithospheric-scale rheological anomaly at this belt. The magnetic alignments show a trend similar to that of geological units in southeastern NCC and adjacent areas, although they differ from the SKS-splitting fast polarization directions, except in the Qinling-Dabie orogen where a vertical coherent deformation of the crust and mantle may be involved there. Based on the geophysical data, we propose a detachment-controlled model, which was caused by the different detachment depth/strength, for the formation of XHTB to explain its arcuate shape as well as the magnetic alignments, thus providing new insight into the deep processes of southeastern NCC.
      PubDate: 2022-04-01
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 3.235.24.113
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-