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  Subjects -> ENGINEERING (Total: 2169 journals)
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ENGINEERING (1176 journals)            First | 2 3 4 5 6 7 8 9 | Last

International Journal of Grid and Utility Computing     Hybrid Journal  
International Journal of Heat and Fluid Flow     Hybrid Journal   (Followers: 15)
International Journal of Heat and Mass Transfer     Hybrid Journal   (Followers: 121)
International Journal of Heavy Vehicle Systems     Hybrid Journal   (Followers: 6)
International Journal of Hypersonics     Full-text available via subscription   (Followers: 3)
International Journal of Imaging Systems and Technology     Hybrid Journal   (Followers: 2)
International Journal of Impact Engineering     Hybrid Journal   (Followers: 7)
International Journal of Information Acquisition     Hybrid Journal   (Followers: 1)
International Journal of Innovation and Applied Studies     Open Access   (Followers: 3)
International Journal of Innovation Science     Full-text available via subscription   (Followers: 6)
International Journal of Innovative Technology and Research     Open Access  
International Journal of Integrated Engineering     Open Access   (Followers: 1)
International Journal of Intelligent Engineering Informatics     Hybrid Journal  
International Journal of Intelligent Systems and Applications in Engineering     Open Access  
International Journal of Lifecycle Performance Engineering     Hybrid Journal   (Followers: 1)
International Journal of Machine Tools and Manufacture     Hybrid Journal   (Followers: 5)
International Journal of Manufacturing Research     Hybrid Journal   (Followers: 5)
International Journal of Manufacturing Technology and Management     Hybrid Journal   (Followers: 7)
International Journal of Materials and Product Technology     Hybrid Journal   (Followers: 4)
International Journal of Mathematical Education in Science and Technology     Hybrid Journal   (Followers: 7)
International Journal of Mathematics in Operational Research     Hybrid Journal   (Followers: 1)
International Journal of Medical Engineering and Informatics     Hybrid Journal   (Followers: 5)
International Journal of Micro Air Vehicles     Full-text available via subscription   (Followers: 4)
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 1)
International Journal of Microwave Science and Technology     Open Access   (Followers: 2)
International Journal of Mobile Network Design and Innovation     Hybrid Journal   (Followers: 3)
International Journal of Multiphase Flow     Hybrid Journal   (Followers: 2)
International Journal of Nanomanufacturing     Hybrid Journal   (Followers: 1)
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Nanotechnology     Hybrid Journal   (Followers: 5)
International Journal of Nanotechnology and Molecular Computation     Full-text available via subscription   (Followers: 3)
International Journal of Navigation and Observation     Open Access   (Followers: 8)
International Journal of Network Management     Hybrid Journal  
International Journal of Nonlinear Sciences and Numerical Simulation     Hybrid Journal  
International Journal of Numerical Methods for Heat & Fluid Flow     Hybrid Journal   (Followers: 7)
International Journal of Optics     Open Access   (Followers: 1)
International Journal of Organisational Design and Engineering     Hybrid Journal   (Followers: 10)
International Journal of Pattern Recognition and Artificial Intelligence     Hybrid Journal   (Followers: 6)
International Journal of Pavement Engineering     Hybrid Journal   (Followers: 3)
International Journal of Physical Modelling in Geotechnics     Hybrid Journal   (Followers: 3)
International Journal of Plasticity     Hybrid Journal   (Followers: 6)
International Journal of Plastics Technology     Hybrid Journal   (Followers: 1)
International Journal of Polymer Analysis and Characterization     Hybrid Journal   (Followers: 5)
International Journal of Polymer Science     Open Access   (Followers: 16)
International Journal of Precision Engineering and Manufacturing     Hybrid Journal   (Followers: 5)
International Journal of Precision Engineering and Manufacturing-Green Technology     Hybrid Journal  
International Journal of Precision Technology     Hybrid Journal  
International Journal of Pressure Vessels and Piping     Hybrid Journal   (Followers: 3)
International Journal of Production Economics     Hybrid Journal   (Followers: 13)
International Journal of Quality and Innovation     Hybrid Journal   (Followers: 4)
International Journal of Quality Assurance in Engineering and Technology Education     Full-text available via subscription   (Followers: 2)
International Journal of Quality Engineering and Technology     Hybrid Journal   (Followers: 2)
International Journal of Quantum Information     Hybrid Journal  
International Journal of Rapid Manufacturing     Hybrid Journal   (Followers: 3)
International Journal of Reliability, Quality and Safety Engineering     Hybrid Journal   (Followers: 7)
International Journal of Renewable Energy Technology     Hybrid Journal   (Followers: 8)
International Journal of Robust and Nonlinear Control     Hybrid Journal   (Followers: 3)
International Journal of Science Engineering and Advance Technology     Open Access  
International Journal of Sediment Research     Full-text available via subscription   (Followers: 1)
International Journal of Self-Propagating High-Temperature Synthesis     Hybrid Journal   (Followers: 2)
International Journal of Signal and Imaging Systems Engineering     Hybrid Journal  
International Journal of Six Sigma and Competitive Advantage     Hybrid Journal  
International Journal of Social Robotics     Hybrid Journal   (Followers: 2)
International Journal of Software Engineering and Knowledge Engineering     Hybrid Journal   (Followers: 2)
International Journal of Space Science and Engineering     Hybrid Journal   (Followers: 2)
International Journal of Speech Technology     Hybrid Journal   (Followers: 4)
International Journal of Spray and Combustion Dynamics     Full-text available via subscription   (Followers: 6)
International Journal of Superconductivity     Open Access  
International Journal of Surface Engineering and Interdisciplinary Materials Science     Full-text available via subscription   (Followers: 1)
International Journal of Surface Science and Engineering     Hybrid Journal   (Followers: 8)
International Journal of Sustainable Engineering     Hybrid Journal   (Followers: 7)
International Journal of Sustainable Manufacturing     Hybrid Journal   (Followers: 4)
International Journal of Systems and Service-Oriented Engineering     Full-text available via subscription  
International Journal of Systems Assurance Engineering and Management     Hybrid Journal  
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 2)
International Journal of Technoethics     Full-text available via subscription   (Followers: 1)
International Journal of Technology Management and Sustainable Development     Hybrid Journal   (Followers: 1)
International Journal of Technology Policy and Law     Hybrid Journal   (Followers: 5)
International Journal of Telemedicine and Applications     Open Access   (Followers: 2)
International Journal of Thermal Sciences     Hybrid Journal   (Followers: 7)
International Journal of Thermodynamics     Open Access   (Followers: 2)
International Journal of Turbo & Jet-Engines     Hybrid Journal  
International Journal of Ultra Wideband Communications and Systems     Hybrid Journal  
International Journal of Vehicle Autonomous Systems     Hybrid Journal   (Followers: 1)
International Journal of Vehicle Design     Hybrid Journal   (Followers: 7)
International Journal of Vehicle Information and Communication Systems     Hybrid Journal   (Followers: 2)
International Journal of Vehicle Noise and Vibration     Hybrid Journal   (Followers: 3)
International Journal of Vehicle Safety     Hybrid Journal   (Followers: 5)
International Journal of Vehicular Technology     Open Access   (Followers: 2)
International Journal of Virtual Technology and Multimedia     Hybrid Journal   (Followers: 4)
International Journal of Wavelets, Multiresolution and Information Processing     Hybrid Journal  
International Journal on Artificial Intelligence Tools     Hybrid Journal   (Followers: 4)
International Nano Letters     Open Access   (Followers: 9)
International Review of Applied Sciences and Engineering     Full-text available via subscription  
International Scholarly Research Notices     Open Access   (Followers: 220)
Inverse Problems in Science and Engineering     Hybrid Journal   (Followers: 2)
Ionics     Hybrid Journal  
IPTEK The Journal for Technology and Science     Open Access  
IRBM News     Full-text available via subscription  
Ironmaking & Steelmaking     Hybrid Journal   (Followers: 2)

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Journal Cover   Journal of Electronic Imaging
  [SJR: 0.367]   [H-I: 46]   [2 followers]  Follow
    
   Partially Free Journal Partially Free Journal
   ISSN (Print) 1017-9909 - ISSN (Online) 1560-229X
   Published by SPIE - International Society for Optical Engineering Homepage  [7 journals]
  • Emplacement of serpentinites in the Chohar Gonbad-Gugher-Baft ophiolitic
           mélange, southeast Iran: examination of the mineral–chemical,
           petrologic, and structural features
    • Abstract: Abstract The Chohar Gonbad-Gugher-Baft ophiolite mélange, located along the major Baft and Shahr-e-Babak fault zones, southeast Iran, represents remnants of Neo-Tethyan oceanic lithosphere. This mélange contains blocks of harzburgite, dunite, lherzolite, basalt, and other ophiolite-related lithologies tectonically mixed with and embedded in a serpentinite matrix. Field, petrographic, and geochemical data show that peridotites in this mélange belong to the upper mantle. They seem to have undergone up to ~20 % partial melting in a supra-subduction zone setting, based on their spinel Cr# values (0.21–0.53). Chemical compositions and textures in the serpentinites indicate that they were partially hydrated during emplacement and further mobilized diapirically to the surface. The different deformation stages occurred in an accretionary wedge environment. Petrographic evidence shows that the first serpentinization event produced mesh-textured serpentinites formed under static conditions in an ocean floor environment (Nain-Baft ocean crust), where the initial lizardite, bastite, and chrysotile veins formed. Plastic deformation occurred due to the subduction of Nain-Baft oceanic lithospheric beneath the central Iranian microcontinent, with antigorite-bearing flare-textured serpentinites produced. During progressive exhumation of the Nain-Baft ophiolite mélange, the serpentinites were affected by ductile, ductile–brittle, and brittle deformation, respectively. Accretion and resultant diapirism are the most important processes in the emplacement of serpentinite, which is a consequence of hydration of the ocean crust. In this example, late-stage emplacement via thrusting occurred along the northern extent of the southern Sanandaj–Sirjan zone (S–SZ).
      PubDate: 2015-05-14
       
  • The Pyrenean inversion phase in northern Belgium: an example of a
           relaxation inversion'
    • Abstract: Abstract The analysis of 2D seismic and well data provides new insights into the late Eocene to earliest Oligocene dynamics along the southern border of the North Sea area, Belgium. From the start of the Priabonian onwards, the northwestern part of the Campine Basin and the London–Brabant Massif to its west experienced subsidence and developed into a shallow trough. Simultaneously, several other southern North Sea basins, including the central and eastern part of the Campine Basin and the Roer Valley Graben, were inverted by what is generally referred to as the Pyrenean inversion phase. Inversion caused broad flexural uplift and minor reverse fault movements. The characteristics of inversions in the southern North Sea basins are very similar to each other and to those described for a phase of intraplate stress relaxation. The results of this study therefore suggest that the Pyrenean inversion phase was triggered by a regional stress relaxation that started around the Bartonian/Priabonian boundary and ended before the onset of the Oligocene.
      PubDate: 2015-05-14
       
  • Timing and nature of the Xinlin–Xiguitu Ocean: constraints from
           ophiolitic gabbros in the northern Great Xing’an Range, eastern
           Central Asian Orogenic Belt
    • Abstract: Abstract Jifeng ophiolitic mélange (ultramafic rocks, meta-basalts and gabbros) crops out in the northern segment of the Great Xing’an Range, the eastern segment of the Central Asian Orogenic Belt, which marks the closure of the Xinlin–Xiguitu Ocean associated with the collision between the Erguna block and Xing’an block. In order to investigate the formation age and magma source of the Jifeng ophiolitic mélange, the gabbros from newly discovered the Jifeng ophiolitic mélange are studied with zircon U–Pb ages, whole-rock geochemistry and zircon Hf isotopes. Zircon U–Pb dating from the ophiolitic gabbros yields U–Pb age of 647 ± 5.3 Ma, which may represent the formation age of the ophiolitic mélange. The gabbros display low SiO2, TiO2, K2O contents, high Na2O, LREE contents and indistinctive REE fractionation [(La/Yb)N = 1.97–2.98]. It shows an E-MORB-like affinity, while the element concentrations of the Jifeng samples are lower than that of E-MORB. More importantly, Nb displays negative anomaly in comparison with Th, which shows a transitional SSZ-type ophiolite signature. Moreover, the ε Hf (t) values of ~647 Ma zircons in the gabbros range from +8.4 to +13.4, and the corresponding Hf single-stage ages (T DM1) are between 687 and 902 Ma, which is obviously older than the crystallization age of 647 Ma. These geochemical features can be explained as melts from the partial melting of a depleted mantle source meta-somatized by fluids derived from a subducted slab. Accordingly, we conclude that the Jifeng ophiolitic mélange is probably related to transitional SSZ-type ophiolite and developed in an intra-oceanic subduction, which indicates that an ocean (the Xinlin–Xiguitu Ocean) existed between the Erguna block and Xing’an block. The Ocean’s formation might be no later than the Neoproterozoic (647 Ma), and it was closed in the Late Cambrian because of the collision between the Erguna block and Xing’an block.
      PubDate: 2015-05-08
       
  • Mineralogy and mineral chemistry of detrital heavy minerals from the Rhine
           River in Germany as evidence to their provenance, sedimentary and
           depositional history: focus on platinum-group minerals and remarks on
           cassiterite, columbite-group minerals and uraninite
    • Abstract: Abstract In the course of studying the gold-bearing heavy mineral spectrum of sediments from the upper Rhine River, a distinct suite of detrital grains comprising platinum-group minerals (PGM), cassiterite, columbite-group minerals and uraninite was identified and investigated using conventional and modern analytical methods. This study aimed to characterize the selected mineral groups mineralogically and geochemically in order to identify possible source areas and to reconstruct different aspects of the complex sedimentary history of the Rhine River sediments. The PGM assemblage is dominated by grains of Ru–Os–Ir alloys (~70 %), followed by Pt–Fe alloys, sperrylite and rare other PGM. Accordingly, this PGM assemblage represents highly mature, physically and chemically extremely resistant compounds which may have experienced and survived repeated reworking during their sedimentary history. Pt–Fe alloys and sperrylite may originate from various sources; however, the predominant Ru–Os–Ir alloy grains point to an origin from ophiolite sequences of unknown age (but likely pre-Alpine; Variscan or older). The exact locations of the primary sources and the complex, prolonged sedimentary history of the detrital PGM with possibly multiple intermittent storages remain unknown. Detrital cassiterite grains were dated by the U–Pb method using LA-ICP-MS. The age dates of cassiterite largely overlap with zircon age distributions by peaking distinctly at ca. 325 Ma (majority of ages), thereby implying a predominantly Variscan age of the cassiterite grains and possible derivation from mineralization in the Black Forest area. Columbite-group minerals are dominantly tapiolite originating from pegmatites. Rare uraninite grains attest that this mineral experienced rapid erosion, transport and deposition in a reducing environment.
      PubDate: 2015-05-08
       
  • Monazite U–Th–Pb EPMA and zircon U–Pb SIMS chronological
           constraints on the tectonic, metamorphic, and thermal events in the inner
           part of the Variscan orogen, example from the Sioule series, French Massif
           Central
    • Abstract: Abstract In the northern Variscan French Massif Central, the Sioule metamorphic series exposes from top to bottom the tectonic superposition of the Upper Gneiss Unit (UGU), Lower Gneiss Unit (LGU), and Para-autochthonous Unit (PAU). The nappe stacking developed throughout two prograde syn-metamorphic events: D1 is a top-to-the-SW shearing coeval with a probable Devonian migmatization and D2 is a top-to-the-NW shearing event. Both events were completed before the unconformable deposition of the undeformed and unmetamorphosed “Tufs anthracifères” formation, dated at ca 330 Ma (Late Visean). Furthermore, the UGU experienced a high-pressure metamorphism ascribed to a D0 event during which eclogite or granulite crystallized in several parts of the UGU. Monazite U–Th–Pb and zircon U–Pb SIMS datings were carried out in order to constrain the ages of these D0, D1, and D2 tectono-metamorphic events. These new geochronological results are placed in a P–T-t diagram constructed for the UGU, LGU, and PAU. Monazite sampled in UGU, LGU, and PAU rocks yields similar 365–350 Ma ages consistent with the D2 event dated in other places of the French Massif Central. A zoned monazite grain from a granulitic paragneiss yields 416 ± 15 and 362 ± 14 Ma ages interpreted as those of the D0 and D2 events, respectively. Zircon from the same granulitic paragneiss yields SIMS ages at 343 ± 2 and 328 ± 2 Ma that are interpreted as recrystallization processes associated with post-thickening thermal events, possibly recording the onset of orogenic collapse of the Northern Massif Central. It is worth to note that neither monazite nor zircon recorded the D1 event.
      PubDate: 2015-05-06
       
  • Geochronology and geochemistry of tuff beds from the Shicaohe Formation of
           Shennongjia Group and tectonic evolution in the northern Yangtze Block,
           South China
    • Abstract: Abstract Meso- to Neoproterozoic magmatic events are widespread in the Yangtze Block. The geochronology and tectonic significance of the Shennongjia Group in the Yangtze Block are still highly controversial. An integrated geochronology and geochemistry approach provides new insights into the geochronological framework, tectonic setting, magmatic events, and basin evolution of the northern Yangtze Block. Our new precise sensitive high-resolution ion microprobe U–Pb data indicate a deposition age of 1180 ± 15 Ma for the Shicaohe Formation subalkaline basaltic tuff that is geochemically similar to modern intracontinental rift volcanic rocks. The integration of available geochemical data together with our new U–Pb ages indicates the Shicaohe Formation subalkaline basaltic tuff formed ca. 1180 in a continental rift-related setting on a passive continental margin. The Shennongjia Group is topped by the Zhengjiaya Formation volcanic sequence, indicating arc-related igneous events at 1103 Ma. The transition of the late Mesoproterozoic tectonic regime from intracontinental extension to convergence occurred between ca. 1180 and 1103 Ma in the northern Yangtze Block. Tectonic evolution in the Neoproterozoic led to accretion along the northern margin of the Yangtze Block. These results provide geochronological evidence, which is of utmost importance for reconfiguration of the chronostratigraphic framework and for promoting research on Mesoproterozoic strata in China, thereby increasing understanding of magmatic events and basin evolutionary history in the northern Yangtze Block.
      PubDate: 2015-05-01
       
  • Kashmir Basin Fault and its tectonic significance in NW Himalaya, Jammu
           and Kashmir, India
    • Abstract: Abstract The Kashmir Basin Fault is located in the Jammu and Kashmir region of Kashmir Basin in NW Himalaya, India. It is a classic example of an out-of-sequence thrust faulting and is tectonically active as observed from multiple geological evidences. Its geomorphology, structure and lateral extent indicate significant accommodation of stress since long, which is further supported by the absence of a large earthquake in this region. It seems this fault is actively accommodating some portion of the total India–Eurasia convergence, apart from two well-recognised active structures the Medlicott–Wadia Thrust and the Main Frontal Thrust, which are referred in Vassallo et al. (Earth Planet Sci Lett 411:241–252, 2015). This requires its quantification and inclusion into slip distribution scheme of NW Himalaya. Therefore, it should be explored extensively because this internal out-of-sequence thrust could serve major seismic hazard in KB, repeating a situation similar to Muzaffarabad earthquake of Northern Pakistan in 2005.
      PubDate: 2015-04-30
       
  • The transition from thick-skinned to thin-skinned tectonics in the
           Basque-Cantabrian Pyrenees: the Burgalesa Platform and surroundings
    • Abstract: Abstract Interpretation of seismic data in the margins of the Burgalesa Platform in the Basque-Cantabrian Pyrenees has allowed proposition of a new structural model that combines different modes of deformation during oblique tectonic inversion, conditioned by the distribution of Triassic salts. Deformation was decoupled by the presence of the salt horizon between basement-involved thrusts inverting formerly Triassic and Late Jurassic–Early Cretaceous extensional faults and a detached thrust system involving the Upper Triassic to Neogene sedimentary package. Structural units experiencing different styles of deformation are not only stacked vertically above and below the salt, but most importantly, they change from one to the other along-strike across the transversal edges of the Triassic salts. The Burgalesa Platform detached thrust system was confined between the basement-involved structures of the Cantabrian Mountains westward and the NW tip of the Iberian basement-involved structures (San Pedro) southward. This together with the obliquity between the Pyrenean shortening direction and the strike of the previous extensional faults, mostly during the late stages of deformation, determined the strike-slip reactivation of the basement-involved inverted faults and the lateral extrusion of the Burgalesa Platform detached Mesozoic successions above the salt towards the SE to form a prominent thrust salient oblique to the main Pyrenean trend. The proposed model combines thick-skinned with thin-skinned structural styles during oblique tectonic inversion and is consistent with the surface data, including the fracture system, the available subsurface data and the mechanical stratigraphy.
      PubDate: 2015-04-23
       
  • Structural model of the Balkassar area, Potwar Plateau, Pakistan
    • Abstract: Abstract Balkassar is an important hydrocarbon producing area of the Potwar Plateau, Pakistan. Two-dimensional seismic reflection data of the area revealed tectonically controlled, distinct episodes of (1) normal faulting in the basement followed by (2) reverse faulting in the cover sequence. Himalayan orogeny and associated diapirism of the Precambrian Salt Range Formation have produced many salt-cored anticlines in the Potwar Plateau, and one such salt-cored anticline is present in the Balkassar. This anticline has NE–SW-oriented axis, and both the SE and NW limbs are bounded by reverse faults. The basement normal faults indicate Jurassic rifting and splitting of Pangaea. We interpret reverse faults with dip angles of about 60°–75° in the cover sequence, having both hinterland and foreland vergence. Both NW- and SE-dipping faults are present in contrast to the only southward-directed thrusts of previous models. Duplexes and triangle zones, which are common in the northern part of the Potwar Plateau, are not developed in the Balkassar area due to comparatively less crustal shortening in the area. The present interpretation can help in understanding the complex structures in other parts of the Potwar Plateau for hydrocarbons exploration and also in deformed foreland basins worldwide that display similar characteristics but are considered to be dominated by low-angle thrust tectonics.
      PubDate: 2015-04-18
       
  • The origin of the Avram Iancu U–Ni–Co–Bi–As
           mineralization, Băiţa (Bihor) metallogenic district, Bihor Mts.,
           Romania
    • Abstract: Abstract The Băiţa metallogenic district in the Bihor Mountains is a historically important mining area in Romania. Uranium mining took place between 1952 and 1998 from various deposits, but very little is known about the geology and mineralogy of these deposits. In this paper, we describe geology and mineralogy of uranium mineralization of the Avram Iancu uranium mine from waste dump samples collected before complete remediation of the site. Texturally and mineralogically complex assemblages of nickeline, cobaltite–gersdorffite solid solution, native Bi, Bi-sulfosalts, molybdenite, and pyrite–chalcopyrite–sphalerite occur with uraninite, “pitchblende,” and brannerite in most of the ore samples. The association of nickel, cobalt, and arsenic with uranium is reminiscent of five-element association of vein type U–Ni–Co–Bi–As deposits; however, the Avram Iancu ores appear to be more replacement-type stratiform/stratabound. Avram Iancu ore samples contain multistage complex, skarn, uranium sulfide, arsenide assemblages that can be interpreted to have been formed in the retrograde cooling stages of the skarn hydrothermal system. This mineralizing system may have built-up along Upper Cretaceous–Paleogene “Banatite” intrusions of diorite-to-granite composition. The intrusions crosscut the underlying uraniferous Permian formations in the stacked NW-verging Biharia Nappe System. The mineralization forms stacked, multilayer replacement horizons, along carbonate-rich lithologies within the metavolcanic (tuffaceous) Muncel Series. Mineral paragenesis and some mineral chemistry suggest moderate-to-high <450, i.e., 350–310 °C, formation temperatures for the uranium sulfide stage along stratigraphically controlled replacement zones and minor veins. Uranium minerals formed abundantly in this early stage and include botryoidal, sooty and euhedral uraninite, brannerite, and coffinite. Later and/or lower-temperature mineral assemblages include heterogeneous, complexly zoned arsenide–sulfarsenide solid solutions associated with minute but abundant uranium minerals. Within the later arsenide–sulfarsenide mineral assemblage, there is great variation in Ni, Co, and S content with generally increasing arsenic content. Uranium minerals in this late-stage assemblage include very fine euhedral uraninite and brannerite inclusions in arsenide–sulfarsenide minerals. Native bismuth and Bi-sulfosalt krupkaite are observed in this As–S-rich assemblage strongly associated with cobaltite.
      PubDate: 2015-04-18
       
  • Strike-slip tectonics in the Pannonian basin based on seismic surveys at
           Lake Balaton
    • Abstract: Abstract Strike-slip tectonics has been the dominant style of deformation during the neotectonic (Pliocene and Quaternary) evolution of the Pannonian basin. Main faults are exposed in the “island mountains” of the basin, but strike-slip tectonic features can be best studied in the basin fill by seismic data. Lake Balaton offers the opportunity to carry out high to ultra-high-resolution seismo-acoustic surveys to image stratigraphic and tectonic features in the central part of the Pannonian basin. Several campaigns in the lake using different acquisition techniques have resulted in more than 2000-km seismo-acoustic profiles with a range of resolutions and penetration depths. Interpretation of faults and folds shows a few kilometers wide shear zone below the lake in Late Miocene–Pliocene strata. This zone can be identified as the continuation of the Balatonfő line known onshore to the east of the lake. Mapping revealed a set of duplex structures and highlighted the importance of this shear zone in the formation of Lake Balaton. Comparison of our results to analogue clay models suggests that the observed shear zone is sinistral and the horizontal displacement is on the order of hundreds of meters. Looking at 3D industrial seismic data to the south of the lake, we suggest that the first-order Balaton line, which represents the continuation of Periadriatic line, is also sinistral and characterized by small horizontal displacement of about 1.0–1.5 km during Pliocene and Quaternary times. This indicates a 0.2–0.3 mm/year average slip rate, which is compatible with recent GPS measurements.
      PubDate: 2015-04-17
       
  • Shaping the Rwenzoris: balancing uplift, erosion, and glaciation
    • Abstract: Abstract The Rwenzori Mountains in Africa represent an extremely uplifted basement fault block at the eastern edge of the western branch of the East African Rift system, a large-scale rift system controlled by extensional stresses. The rugged alpine topography reaches an altitude of up to 5109 m, and the highest parts are ice-covered. Glacial landforms and moraines proof repeated more extensive glaciations during the last glacial cycles. In order to elucidate magnitudes and the varying role of erosional processes in shaping the relief of the Rwenzori Mountains over the past 2 mill. years, we performed numerical simulations with the landscape evolution programme ULTIMA THULE. It is controlled by a climate driver with temperature as a master variable as well as changing precipitation and evapotranspiration over time. The morphological processes considered are fluvial erosion, hillslope diffusion, and glacial abrasion, and the latter controlled by the simulated glaciation of the landscape. We provide three sets of model runs: the first one starting from the present-day topography and running for approx. 800 ka, the second one extending the modelling period to 2 Ma, and the third one starting from a peneplain and evolving for 2 Ma. Our results provide constraints on the temperature history of the Rwenzori Mountains, the interplay of morphological degradation and tectonic uplift, and a time frame for the formation of the mountain chain from a peneplain to the present relief. The modelled landscape evolves from a peneplain 2 Ma ago to a Rwenzori-type mountain range, when the fairly strong average rock uplift of 1–2 mm year−1 is compensated by a strong fluvial erosion component. The rock uplift rate is needed to obtain elevations above the equilibrium line altitude around 500 ka BP and results in surface uplift over time. Around that time, a periodic ice cap appears in the models, and glacial abrasion then limits the height of the Rwenzori Mountains to its present elevation.
      PubDate: 2015-04-14
       
  • Re–Os geochronology on sulfides from the Tudun Cu–Ni sulfide
           deposit, Eastern Tianshan, and its geological significance
    • Abstract: Abstract The Tudun deposit is a medium-sized Cu–Ni sulfide deposit, located at the westernmost edge of the Huangshan–Jing’erquan Belt in the northern part of Eastern Tianshan, NW China. Sulfide separates including pentlandite, pyrrhotite and chalcopyrite from the Tudun deposit, contain Re, common Os and 187Os ranging from 40.46 to 201.2, 0.8048 to 6.246 and 0.1709 to 0.9977 ppb, respectively. They have very low 187Os/188Os ratios of 1.224–2.352. The sulfides yield a Re–Os isochron age of 270.0 ± 7.5 Ma (MSWD = 1.3), consistent within uncertainty with the SHRIMP zircon U–Pb age for the Tudun mafic intrusion (gabbro) of 280.0 ± 3.0 Ma. The calculated initial 187Os/188Os ratio is 0.533 ± 0.022, and γOs values range from 283 to 307, with a mean of 297, indicating significant crustal contamination of the parent melt prior to sulfide saturation. The Tudun deposit shares the same age and Re–Os isotopic compositions with other orthomagmatic Cu–Ni sulfide deposits in Huangshan–Jing’erquan Belt, suggesting that they have formed in Early Permian.
      PubDate: 2015-04-14
       
  • The Rwenzori Mountains, a Palaeoproterozoic crustal shear belt crossing
           the Albertine rift system
    • Abstract: Abstract This contribution discusses the development of the Palaeoproterozoic Buganda-Toro belt in the Rwenzori Mountains and its influence on the western part of the East African Rift System in Uganda. The Buganda-Toro belt is composed of several thick-skinned nappes consisting of Archaean Gneisses and Palaeoproterozoic cover units that are thrusted northwards. The high Rwenzori Mountains are located in the frontal unit of this belt with retrograde greenschist facies gneisses towards the north, which are unconformably overlain by metasediments and amphibolites. Towards the south, the metasediments are overthrust by the next migmatitic gneiss unit that belongs to a crustal-scale nappe. The southwards dipping metasedimentary and volcanic sequence in the high Rwenzori Mountains shows an inverse metamorphic grade with greenschist facies conditions in the north and amphibolite facies conditions in the south. Early D1 deformation structures are overgrown by cordierite, which in turn grows into D2 deformation, representing the major northwards directed thrusting event. We argue that the inverse metamorphic gradient develops because higher grade rocks are exhumed in the footwall of a crustal-scale nappe, whereas the exhumation decreases towards the north away from the nappe leading to a decrease in metamorphic grade. The D2 deformation event is followed by a D3 E-W compression, a D4 with the development of steep shear zones with a NNE-SSW and SSE-NNW trend including the large Nyamwamba shear followed by a local D5 retrograde event and D6 brittle reverse faulting. The Palaeoproterozoic Buganda-Toro belt is relatively stiff and crosses the NNE-SSW running rift system exactly at the node where the highest peaks of the Rwenzori Mountains are situated and where the Lake George rift terminates towards the north. Orientation of brittle and ductile fabrics show some similarities indicating that the cross-cutting Buganda-Toro belt influenced rift propagation and brittle fault development within the Rwenzori Mountains and that this stiff belt may form part of the reason why the Rwenzori Mountains are relatively high within the rift.
      PubDate: 2015-04-04
       
  • Sedimentary development and correlation of Late Quaternary terraces in the
           Kyrenia Range, northern Cyprus, using a combination of sedimentology and
           optical luminescence data
    • Abstract: Abstract This study focuses on the younger of a series of Quaternary terraces along the flanks of the Kyrenia Range in northern Cyprus, specifically the Kyrenia (Girne) and the Koupia terraces. The Kyrenia (Girne) terrace is tentatively correlated with oxygen isotope stage 5 (125 Ka), and the Koupia terrace with oxygen isotope stage 3 (<50 Ka). Along the northern flank of the range, the Kyrenia (Girne) terrace deposits (5–20 m above modern sea level) typically begin with a basal lag conglomerate and then pass upwards into shallow-marine calcarenites and then into variable aeolianites, paleosols and fluvial deposits (up to 20 m thick). In contrast, the Koupia terrace (<2 m above modern sea level) consists of aeolianites and shallow-marine calcarenites (up to 8 m thick). The equivalent deposits along the southern flank of the range are entirely non-marine fluvial mud, sands and conglomerates. The marine to continental terrace systems can be tentatively correlated based on mapping, height above modern sea level and sedimentary facies. However, variable preservation and patchy exposure require such correlations to be independently tested. To achieve this, a portable optically stimulated luminescence (OSL) reader was used to determine the luminescence characteristics of the two terrace systems. Luminescence profiles show major differences in luminescence characteristics between the two terrace depositional systems, which can be related to sedimentary processes, provenance and age. These features allow sections in different areas to be effectively correlated. Individual sections show luminescence properties that are generally consistent with an expected up-sequence decrease in age. However, the younger Koupia terrace deposits show higher luminescence intensities compared with the older Kyrenia (Girne) terrace deposits. This can be explained by multiple phases of reworking of the Kyrenia (Girne) terrace deposits, which changed the luminescence characteristics of the sediment. The use of the portable OSL reader is therefore an effective means of correlating Late Quaternary terrace deposits in northern Cyprus and probably also elsewhere.
      PubDate: 2015-04-02
       
  • Detrital zircon geochronology in blueschist-facies meta-conglomerates from
           the Western Alps: implications for the late Carboniferous to early Permian
           palaeogeography
    • Abstract: Abstract In the Western Alps, the Money Complex of the Gran Paradiso Massif, metamorphosed under blueschist facies during the Alpine cycle, is considered to be Permo-Carboniferous in age, but no palaeontological or radiometric data constrain this interpretation. A revision of the lithostratigraphy of the Money Complex allows recognizing a polygenic (graphite-rich) and a monogenic (graphite-poor) meta-sedimentary formation. Detrital zircon U–Pb geochronology in both meta-sedimentary formations shows that (i) the main population is Cambrian and Ordovician in age, (ii) the youngest grains are Silurian and Lower Devonian, and (iii) Carboniferous zircon grains are lacking. A careful study of the age distributions in the Alps suggests that potential source for the detrital material in the Money Complex is the Briançonnais basement. Late Carboniferous magmatism is widespread in the Helvetic Zone of the Alps. Permian magmatism is dominant in the Briançonnais, the Austroalpine and the Southalpine basements. The lack of Carboniferous zircons in the Money Complex suggests that the detritus was not shed from the Helvetic zone, which was separated from the Money basin by the Zone Houillère basin, where the main drainage pattern was developed from south to north and where the depocenters migrated northwards from the Upper Missisippian to Upper Pennsylvanian. We suggest that the Money Complex may had been located to the east of the main river drainage inside the Zone Houillère basin or alternatively may represent a small basin, located on the east of the Zone Houillère.
      PubDate: 2015-04-01
       
  • Transcurrent nature of the Teisseyre–Tornquist Zone in Central
           Europe: results of the POLCRUST-01 deep reflection seismic profile
    • Abstract: Abstract Teisseyre–Tornquist Zone (TTZ) corresponds to a crustal boundary between the Precambrian East European Platform (EEP) and the Palaeozoic West European Platform. Although the zone has been controlling Phanerozoic evolution of large parts of Central Europe, its course, geometry and origin are still poorly constrained. Deep reflection seismic profile POLCRUST-01, recently acquired in SE Poland, for the first time allowed a precise comparison of the Ediacaran and later tectonic patterns to the deep crustal features of the TTZ and adjacent areas. The TTZ corresponds to the subvertical Tomaszów Fault separating the Radom–Kraśnik Elevation, composed of the typical EEP crust, from the Biłgoraj–Narol Block (BNB) in the SW, with a thinned crystalline basement showing affinities to the EEP crust. The BNB is a part of the larger Caledonian Łysogóry Terrane as evidenced by its Lower Palaeozoic stratigraphy and gravity data. Thus, for the first time, the proximal Baltican affinity of this unit has been documented unambiguously. The Łysogóry Terrane is delimited from the SW by the subvertical Cieszanów Fault Zone, corresponding to the Holy Cross Suture. The adjacent Małopolska Terrane is characterized by a distinct Early Palaeozoic stratigraphy, and lower-middle crust exhibiting SW-dipping reflective packages interpreted as NE-verging thrust and shear zones of a Neoproterozoic orogen. The observations from the POLCRUST-01 profile and regional comparisons indicate that the TTZ is a major Caledonian transcurrent zone between Poland and East Romania. In central Poland, the TTZ likely forms a narrow subvertical contact between the EEP and a proximal Kuiavia Terrane, as constrained by the deep refraction seismic data. To the NW, the zone extends towards the Pomeranian part of the Caledonide fold-and-thrust belt related to the Avalonia–Baltica collision zone (Thor Suture). South-east of Poland the TTZ corresponds to the Rava Ruska Fault Zone established as a Caledonian suture separating adjacent terrane, probably of a Baltican affinity. The East Romanian part of the TTZ conforms with the Sfântu Gheorghe Fault separating reworked EEP crust of the Pre-Dobrogean Depression from the North Dobrogea unit bearing a strong Variscan and Cimmerian overprint.
      PubDate: 2015-04-01
       
  • Erratum to: The Alpine nappe stack in western Austria: a crustal-scale
           cross section
    • PubDate: 2015-04-01
       
  • The Ituwa Surge deposits of the Holocene Ngozi caldera, Mbeya Region,
           Tanzania
    • PubDate: 2015-04-01
       
  • The mineralization age of the Makeng Fe deposit, South China: implications
           from U–Pb and Sm–Nd geochronology
    • Abstract: Abstract The Makeng Fe deposit is located in the southwestern Fujian district, South China. The Sm–Nd isochron ages of seven samples of pure garnet and five of pure magnetite separates from the Makeng ores yielded an isochron age of 157 ± 15 Ma. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb dating of the nearby exposed the Dayang–Juzhou (DJ) porphyritic biotite granite and fine-grained syenogranite yielded 206Pb/238U ages of 140.2 ± 1.1 and 140.1 ± 1.0 Ma, respectively. These results suggest that the intrusion of the DJ granite and the Makeng skarn alterations and Fe mineralization are contemporaneous. The DJ granite exhibits geochemical characteristics of A-type granites, including high values of Na2O + K2O (8.13–8.92 wt%), FeOt/MgO (3.4–21.5), and Ga/Al (2.64–3.45 × 10−4), and low Al2O3 (10.71–13.29 wt%) value. Chondrite-normalized rare earth element patterns are characterized by obviously negative Eu anomalies (δEu = 0.02–0.28) and primitive-mantle normalized spidergrams show the enrichment in high field strength element and depleting in Sr, Ti, Ba, and Eu. The geochemical characteristics of DJ granite suggest that the granite was derived from partial melting of the Paleoproterozoic metasedimentary rocks of the Cathaysia basement. And some underplating of mafic magma in the lower tholeiitic crust and/or depleted mantle might be involved and provide the heat source for the partial melting. The DJ granite also fits the spatiotemporal distribution of the Jurassic–Cretaceous coastward migration of both extensional and arc-related magmatism and fills the A-type granites gap in the early stage of the early Cretaceous (145–125 Ma). Therefore, it is suggested that the late Jurassic and early Cretaceous magmatism in southwestern Fujian district were generated in an extensional environment responding to the slab rollback and concomitant retreating arc system of the paleo-Pacific plate within the South China Block. And the Fe metallogeny in southwestern Fujian district is genetically linked with the magmatism during this period.
      PubDate: 2015-04-01
       
 
 
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