Geochemistry and geodynamics of the Mawat mafic complex in the Zagros Suture zone, northeast Iraq     

Hossein Azizi  Ayten Hadi  Yoshihiro Asahara  Youssef Osman Mohammad 《Central European Journal of Geosciences》2013,5(4):523-537

The Iraqi Zagros Orogenic Belt includes two separate ophiolite belts, which extend along a northwest-southeast trend near the Iranian border. The outer belt shows ophiolite sequences and originated in the oceanic ridge or supra-subduction zone. The inner belt includes the Mawat complex, which is parallel to the outer belt and is separated by the Biston Avoraman block. The Mawat complex with zoning structures includes sedimentary rocks with mafic interbedded lava and tuff, and thick mafic and ultramafic rocks. This complex does not show a typical ophiolite sequences such as those in Penjween and Bulfat. The Mawat complex shows evidence of dynamic deformation during the Late Cretaceous. Geochemical data suggest that basic rocks have high MgO and are significantly depleted in LREE relative to HREE. In addition they show positive ? _Nd values (+5 to+8) and low 87Sr/86Sr ratios. The occurrence of some OIB type rocks, high Mg basaltic rocks and some intermediate compositions between these two indicate the evolution of the Mawat complex from primary and depleted source mantle. The absence of a typical ophiolite sequence and the presence of good compatibility of the source magma with magma extracted from the mantle plume suggests that a mantle plume from the D″ layer is more consistent as the source of this complex than the oceanic ridge or supra-subduction zone settings. Based on our proposed model the Mawat basin represents an extensional basin formed during the Late Paleozoic to younger along the Arabian passive margin oriented parallel to the Neo-Tethys oceanic ridge or spreading center. The Mawat extensional basin formed without creation of new oceanic basement. During the extension, huge volumes of mafic lava were intruded into this basin. This basin was squeezed between the Arabian Plate and Biston Avoraman block during the Late Cretaceous.  相似文献   

Lithological Mapping in the Eastern Part of the Central Iranian Volcanic Belt Using Combined ASTER and IRS data   总被引：1，自引：0，他引：1  

Seyed Mohammad Hadi Hadigheh  Hojjatollah Ranjbar 《Journal of the Indian Society of Remote Sensing》2013,41(4):921-931

The study area is located in the eastern part of the central Iranian volcanic belt. Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) and Indian Remote Sensing Satellite (IRS ) pan images were used for applying several image classification methods for lithological mapping. ASTER visible-near infrared and shortwave infrared bands were sharpened using IRS pan image. We used classification methods such as Maximum likelihood, Spectral Angle Mapper (SAM) and Spectral Information Divergence (SID) in order to evaluate the usefulness of these methods for geological mapping. The classification results showed that MLC has the best accuracy and the classified image closely resembles the previously prepared geology map of the area.  相似文献   

Geochemical characterization and modelling of the Toarcian/Domerian porewater at the Tournemire underground research laboratory     

J. Tremosa  D. Arcos  J.M. Matray  F. Bensenouci  E.C. Gaucher  C. Tournassat  J. Hadi 《Applied Geochemistry》2012

For safety evaluation of hazardous waste repositories in clay-rocks, a thorough assessment of porewater chemistry and water–rock interactions is required. However, this objective is a challenging task due to the low hydraulic conductivity and water content of such rocks, which subsequently renders porewater sampling difficult (without inducing perturbations). For this reason, an indirect approach was developed to determine porewater composition of clay-rocks, by a geochemical model of water–rock interaction using some properties of the rock and the solution. The goal of this paper is to obtain the porewater composition of the Toarcian/Domerian argillaceous formation at Tournemire (South of France), for which a reliable model is still lacking. The following work presents a comprehensive characterization of the geochemical system of the Tournemire clay-rock, including mineralogy, petrology, mobile anions, cation exchange properties, accessible porosity and CO₂ partial pressure. Perturbation corrections from fracture water sampling were also computed. These water were found in sealed fractures (Beaucaire et al., 2008) and their radiocarbon apparent age is estimated at 20 ka. Their age together with their equilibrium situation allow considering these fracture waters as representative of the formation porewater. The model developed to calculate the Tournemire porewater composition is essentially based on cation exchange by a multi-site approach, but equilibrium with some mineral phases (calcite, quartz and pyrite) is also considered. Different exchange sites of different affinities towards cations are used, which proportions are given by the mineralogy. Exchange on illite is performed with a three-sites model, while one site is considered for smectite phases. Multi-site model results are compared with corrected fracture water data and two other models: a model only based on mineral equilibrium and a model using cation exchange on one global site. The best results were obtained with the models that take into account cation exchange and particularly with the multi-site model. The interest in considering a model with exchange sites of different affinities is particularly obvious for a satisfactory representation of the K⁺ content in solution. A dependence of K⁺ content to the amount of high affinity sites was observed, leading to an improvement of its simulation when uncertainty on mineralogical data is considered. Once validated, the multi-site model was applied at different levels of the Tournemire argillaceous formation to obtain a profile of the porewater composition.  相似文献   

Shrinkage Properties of Soft Clay Treated with Cement and Geofibers   总被引：4，自引：2，他引：2  

Behzad Fatahi  Thu Minh Le  Behnam Fatahi  Hadi Khabbaz 《Geotechnical and Geological Engineering》2013,31(5):1421-1435

In this study, effects of two types of geofibers, namely polypropylene and recycled carpet, on three dimensional shrinkage properties of cement treated kaolinite and bentonite clays are investigated. Cement treated clay specimens were prepared with cement contents of 5, 10, and 15 % by weight of dry soil for kaolinite samples, and 30, 40 and 50 % for bentonite samples. To investigate and understand the influence of different fiber types and contents, three different percentages of fiber content (i.e. 0.1, 0.2 and 0.5 % polypropylene fibers; and 0.5, 0.75 and 1 % carpet fibers) were adopted. The results of shrinkage tests on 126 cylindrical samples of cement treated clay with various cement and fiber contents were analysed to understand the relationships between these parameters and the shrinkage percentage of treated soil. Results of this study indicate that combination of cement and fiber is effective in reducing the volume change of clayey soils undergoing drying process. In the applied ranges of cement and fiber contents, the influence of cement addition on the shrinkage reduction is more significant than the addition of fibers for the treated kaolinite. However, addition of fibers in curtailing the shrinkage of bentonite clay is more significant than the cement addition.  相似文献   

Editorial     

Hadi Hajibeygi  Jan Dirk Jansen  Olwijn Leeuwenburgh  Denis Voskov 《Computational Geosciences》2017,21(5-6):833-833

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Groundwater Origin in Qanats,Chemo-Isotopic,and Hydrogeological Evidence     

Hojat Mirani Moghadam  Rahim Bagheri  Gholam Hossein Karami  Hadi Jafari 《Ground water》2020,58(5):771-776

A systematic study of the chemo-isotopic characteristics and origin of the groundwater was carried out at six major qanats in the hyper-arid Gonabad area, eastern Iran. These qanats as a sustainable groundwater extraction technology have a long history, supporting human life for more than a thousand years in this region. The Gonabad qanats are characterized by outlet electrical conductivity (EC) values of 750 to 3900 µS/cm and HCO₃-Na-Mg and Cl-Na water types. The Gonabad meteoric water line (G_nMWL) was drawn at the local scale as δ²H = 6.32×δ¹⁸O + 8.35 (with R² = 0.90). It has a lower slope and intercept than the global meteoric water line due to different water vapor sources and isotope kinetic fractionation effects during precipitation in this arid region. The altitude effects on isotopic content of precipitation data were derived as δ¹⁸O = (−0.0031 × H_(m.a.s.l))−1.3). The δ²H and δ¹⁸O isotopes signatures demonstrate a meteoric origin of the groundwater of these qanats. The shift of the qanat's water samples from the local meteoric water line (LMWL) in a dry period with higher temperatures is most probably due to evaporation during the infiltration process and water movement in qanat gallery. Based on the isotopic results and mass balance calculations, the qanats are locally recharged from an area between 2000 to 2400 m.a.s.l of nearby carbonate formations and coarse alluvial sediments. The dissolution of evaporate interlayers in Neogene deposits deteriorates the groundwater quality, especially in Baidokht qanat.  相似文献   

Soil temperature modeling at different depths using neuro-fuzzy,neural network,and genetic programming techniques     

Ozgur?KisiEmail author  Hadi?Sanikhani  Murat?Cobaner 《Theoretical and Applied Climatology》2017,129(3-4):833-848

The applicability of artificial neural networks (ANN), adaptive neuro-fuzzy inference system (ANFIS), and genetic programming (GP) techniques in estimating soil temperatures (ST) at different depths is investigated in this study. Weather data from two stations, Mersin and Adana, Turkey, were used as inputs to the applied models in order to model monthly STs. The first part of the study focused on comparison of ANN, ANFIS, and GP models in modeling ST of two stations at the depths of 10, 50, and 100 cm. GP was found to perform better than the ANN and ANFIS-SC in estimating monthly ST. The effect of periodicity (month of the year) on models’ accuracy was also investigated. Including periodicity component in models’ inputs considerably increased their accuracies. The root mean square error (RMSE) of ANN models was respectively decreased by 34 and 27 % for the depths of 10 and 100 cm adding the periodicity input. In the second part of the study, the accuracies of the ANN, ANFIS, and GP models were compared in estimating ST of Mersin Station using the climatic data of Adana Station. The ANN models generally performed better than the ANFIS-SC and GP in modeling ST of Mersin Station without local climatic inputs.  相似文献   

Modeling landfill site selection by multi-criteria decision making and fuzzy functions in GIS,case study: Shabestar,Iran     

Sara Bahrani  Taghi Ebadi  Hadi Ehsani  Hossein Yousefi  Reza Maknoon 《Environmental Earth Sciences》2016,75(4):337

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Environmental isotope systematics of the groundwater system of southern Kuwait     

Khaled Hadi  U. Saravana Kumar  M. Al-Senafy  H. Bhandary 《Environmental Earth Sciences》2016,75(14):1096

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Monotone multiscale finite volume method     

Yixuan Wang  Hadi Hajibeygi  Hamdi A. Tchelepi 《Computational Geosciences》2016,20(3):509-524

The MultiScale Finite Volume (MSFV) method is known to produce non-monotone solutions. The causes of the non-monotone solutions are identified and connected to the local flux across the boundaries of primal coarse cells induced by the basis functions. We propose a monotone MSFV (m-MSFV) method based on a local stencil-fix that guarantees monotonicity of the coarse-scale operator, and thus, the resulting approximate fine-scale solution. Detection of non-physical transmissibility coefficients that lead to non-monotone solutions is achieved using local information only and is performed algebraically. For these ‘critical’ primal coarse-grid interfaces, a monotone local flux approximation, specifically, a Two-Point Flux Approximation (TPFA), is employed. Alternatively, a local linear boundary condition can be used for the dual basis functions to reduce the degree of non-monotonicity. The local nature of the two strategies allows for ensuring monotonicity in local sub-regions, where the non-physical transmissibility occurs. For practical applications, an adaptive approach based on normalized positive off-diagonal coarse-scale transmissibility coefficients is developed. Based on the histogram of these normalized coefficients, one can remove the large peaks by applying the proposed modifications only for a small fraction of the primal coarse grids. Though the m-MSFV approach can guarantee monotonicity of the solutions to any desired level, numerical results illustrate that employing the m-MSFV modifications only for a small fraction of the domain can significantly reduce the non-monotonicity of the conservative MSFV solutions.  相似文献