Magmatism at continental passive margins inferred from Ambient‐Noise Phase‐velocity in the Gulf of Aden          下载免费PDF全文

Félicie Korostelev  Sylvie Leroy  Derek Keir  Cornelis Weemstra  Lapo Boschi  Irene Molinari  Abdulhakim Ahmed  Graham W. Stuart  Frédérique Rolandone  Khaled Khanbari  Ali Al‐Lazki 《地学学报》2016,28(1):19-26

Non‐volcanic continental passive margins have traditionally been considered to be tectonically and magmatically inactive once continental breakup has occurred and seafloor spreading has commenced. We use ambient‐noise tomography to constrain Rayleigh‐wave phase‐velocity maps beneath the eastern Gulf of Aden (eastern Yemen and southern Oman). In the crust, we image low velocities beneath the Jiza‐Qamar (Yemen) and Ashawq‐Salalah (Oman) basins, likely caused by the presence of partial melt associated with magmatic plumbing systems beneath the rifted margin. Our results provide strong evidence that magma intrusion persists after breakup, modifying the composition and thermal structure of the continental margin. The coincidence between zones of crustal intrusion and steep gradients in lithospheric thinning, as well as with transform faults, suggests that magmatism post‐breakup may be driven by small‐scale convection and enhanced by edge‐driven flow at the juxtaposition of lithosphere of varying thickness and thermal age.  相似文献   

Structural paragenesises of the flysch complexes in the central part of the Uralian Foredeep     

Al. V. Tevelev  Ark. V. Tevelev  I. A. Prudnikov  A. O. Khotylev  E. E. Baraboshkin  S. S. Popov 《Moscow University Geology Bulletin》2016,71(4):290-295

The structural features of the Upper Paleozoic flysch formations in the central part of the Cis-Uralian Foredeep were studied. Three types of structural paragenesises typical of thrust zones were distinguished. Among them are west vergent inclined folds and overfolds that pass into recumbent folds near a fault plane, structured tectonic melange, local thrusts, schistosity zones, and flat slipping planes. The various structural elements extend from northwest to northeast, due to the structural heterogeneity of the allochthon, approximately parallel to the strike of the Karantrav thrust.  相似文献   

Performance of multi-model ensembles for the simulation of temperature variability over Ontario,Canada     

Aly Al Samouly  Chanh Nien Luong  Zhong Li  Spencer Smith  Brian Baetz  Maysara Ghaith 《Environmental Earth Sciences》2018,77(13):524

Climate ensembles utilize outputs from multiple climate models to estimate future climate patterns. These multi-model ensembles generally outperform individual climate models. In this paper, the performance of seven global climate model and regional climate model combinations were evaluated for Ontario, Canada. Two multi-model ensembles were developed and tested, one based on the mean of the seven combinations and the other based on the median of the same seven models. The performance of the multi-model ensembles were evaluated on 12 meteorological stations, as well as for the entire domain of Ontario, using three temperature variables (average surface temperature, maximum surface temperature, and minimum surface temperature). Climate data for developing and validating the multi-model ensembles were collected from three major sources: the North American Coordinated Regional Downscaling Experiment, the Digital Archive of Canadian Climatological Data, and the Climactic Research Unit’s TS v4.00 dataset. The results showed that the climate ensemble based on the mean generally outperformed the one based on the median, as well as each of the individual models. Future predictions under the Representative Concentration Pathway 4.5 (RCP4.5) scenario were generated using the multi-model ensemble based on the mean. This study provides credible and useful information for climate change mitigation and adaption in Ontario.  相似文献   

Tectonic observations in the northern Saih Hatat,Sultanate of Oman   总被引：1，自引：0，他引：1  

Wilfried Bauer  Ivan Callegari  Naila Al Balushi  Ghaliya Al Busaidi  Maryam Al Barumi  Yusra Al Shoukri 《Arabian Journal of Geosciences》2018,11(5):94

The Saih Hatat region, in northeastern Oman, is characterized by a large tectonic window, tectonically overlain during the upper Cretaceous by nappes composed of sedimentary rocks from the Mesozoic Hawasina ocean and the Samail ophiolite. In this window, the autochthonous sedimentary cover of the eastern Arabian Platform from the Late Neoproterozoic to the Cenomanian is well exposed. The oldest of these strata, the Hatat schists, were deformed into a NE-facing fold nappe during the upper Cretaceous. Within the overturned and thrusted lower limb of that fold nappe, we identified three small windows exposing stratigraphically younger Hiyam carbonates and Ordovician sandstone. The structural inventory of the windows and the surrounding area indicates three major tectonic phases. The first deformation led to NNE-SSW trending fold structures which probably formed simultaneously with the major fold nappe of the Hatat schists, followed by the extreme attenuation and thrusting of the lower limb of the fold nappe. The second phase was a gentle folding of the thrust with N-S oriented fold axes and third deformation phase that formed WNW-ESE oriented open folds. The windows are situated in the intersection of anticline axes of these two superposed fold generations and represent a mini basin-and-dome structure with an extension of just 1 km?×?1 km.  相似文献   

Thermodynamic‐based model for coupling temperature‐dependent viscoelastic,viscoplastic, and viscodamage constitutive behavior of asphalt mixtures     

Masoud K. Darabi  Rashid K. Abu Al‐Rub  Eyad A. Masad  Dallas N. Little 《国际地质力学数值与分析法杂志》2012,36(7):817-854

Based on the continuum damage mechanics, a general and comprehensive thermodynamic‐based framework for coupling the temperature‐dependent viscoelastic, viscoplastic, and viscodamage behaviors of bituminous materials is presented. This general framework derives systematically Schapery‐type nonlinear viscoelasticity, Perzyna‐type viscoplasticity, and a viscodamage model analogous to the Perzyna‐type viscoplasticity. The resulting constitutive equations are implemented in the well‐known finite element code Abaqus via the user material subroutine UMAT. A systematic procedure for identifying the model parameters is discussed. Finally, the model is validated by comparing the model predictions with a comprehensive set of experimental data on hot mix asphalt that include creep‐recovery, creep, uniaxial constant strain rate, and repeated creep‐recovery tests in both tension and compression over a range of temperatures, stress levels, and strain rates. Comparisons between model predictions and experimental measurements show that the presented constitutive model is capable of predicting the nonlinear behavior of asphaltic mixes under different loading conditions. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Peculiarities of the Earth’s crust sedimentary layer structure in the Falkland Basin     

A. A. Schreider  E. L. Mazo  A. A. Bulychev  M. P. Kulikova  D. A. Gilod  Al. A. Schreider  A. N. Boiko 《Oceanology》2010,50(6):961-970

An electronic databank including the results of seismic investigations and schemes of the sediment thickness’s distribution patterns was built up for two seismostratigraphic complexes in the Falkland Basin. The interface’s border was dated, and the sedimentation rates were estimated for each complex. An integrated map of the cumulative thickness of the deposits and sedimentation rates was developed. The lowest limits of the parameters of the sedimentation process were characterized for the sedimentary layers affected by compaction and erosion.  相似文献   

Fracture flow modelling based on satellite images of the Wajid Sandstone, Saudi Arabia   总被引：1，自引：0，他引：1  

Conny Zeeb  Daniel Göckus  Paul Bons  Hussain Al Ajmi  Randolf Rausch  Philipp Blum 《Hydrogeology Journal》2010,18(7):1699-1712

Large-scale geological features have been identified by satellite imagery and global positioning system data in the Wajid Sandstone in Saudi Arabia. The main objective is to evaluate the importance of fractures for the overall flow behaviour in this fractured rock aquifer and to estimate in-situ hydraulic apertures. Data on fractures and lineaments were available for three outcrops. By applying a “cut-out” routine on the fracture endpoint data of these fracture trace windows, three deterministic discrete fracture networks (DFN), with an area of 100 m?×?100 m, could be generated. These were used to simulate the fracture flow and to determine the hydraulic conductivity tensors. Using additional data on hydraulic pumping tests and matrix conductivities, in-situ hydraulic apertures could be determined. Average in-situ hydraulic apertures range from 1,300 to 1,700 µm. Observations from the field support these results. In addition, a hydraulic conductivity ratio between the matrix and fracture system was used to identify the contribution of the DFN to the overall fluid transport. A ratio of 10.4 was determined, which indicates that the effective flow behaviour in the Wajid Sandstone aquifer is not entirely dominated by the fracture system, though evidently strongly controlled by it.  相似文献   

Integrated acoustic technologies form new shallow water survey system     

Al Rougeau  Larry Rosenbalm  Carl Sonnier 《Marine Geodesy》2013,36(2-3):187-198

  相似文献   

The properties of the gas in the galactic halo     

Al. A. Suchkov  Yu. A. Shchekinov 《Astrophysics》1986,24(1):74-78

  相似文献   

Late Aptian long‐lived glacio‐eustatic lowstand recorded on the Arabian Plate     

Florian Maurer  Frans S.P. van Buchem  Gregor P. Eberli  Bernard J. Pierson  Madeleine J. Raven  Poul‐Henrik Larsen  Moujahed I. Al‐Husseini  Benoit Vincent 《地学学报》2013,25(2):87-94

  相似文献