Rock Type Identification Using Analysis of the Acoustic Signal Frequency Contents Propagated While Drilling Operation     

Khoshouei  Mehrbod  Bagherpour  Raheb  Jalalian  Mohammad Hossein 《Geotechnical and Geological Engineering》2022,40(3):1237-1250

Geotechnical and Geological Engineering - One of the most important parameters specially in mining and oil drilling fields is the type of rocks. It is important to determine that rock structure is...  相似文献   

First Record of Sexual Dimorphism in Toxasterid Echinoid Heteraster from the Early Cretaceous Deposits of the Kopet-Dagh Basin,NE Iran     

Hossein KAMYABI SHADAN  Morteza TAHERPOUR KHALIL-ABAD 《《地质学报》英文版》2023,97(5):1318-1334

Spatangoid echinoids belonging to Heteraster found in the Lower Cretaceous limestones and calcareous deposits of the Tirgan and Sarcheshmeh formations(Barremian–Aptian) in the Bahman jan-Bala stratigraphic section on the northern flank of the Borouj syncline, situated in the eastern Kopet-Dagh Basin, northeastern Iran are assessed as a sexually dimorphic species. Sexual dimorphism is a common feature in echinoids and, in this study of Heteraster renngarteni Poretzkaja, 1961, sexual dimorphism ha...  相似文献   

Performance evaluation of the M8 algorithm to predict M7+ earthquakes in Turkey     

Masoud Mojarab  Hossein Memarian  Mehdi Zare 《Arabian Journal of Geosciences》2015,8(8):5921-5934

The M8 algorithm is one of the most reliable intermediate-term middle-range earthquake prediction algorithms. The present study evaluates the ability of the M8 algorithm and its modified versions for predicting major events (M7+) in Turkey. Thirty different algorithms were developed by changing the radius of circle of investigation (CI) and the lower magnitude cutoff of the M8 algorithm. These modified algorithms were executed all over the territory of Turkey, and the results were evaluated using the error diagram. Each modified algorithm was executed for consecutive half-year intervals over a specified period of time. Subsequently, the seismic catalog was updated, and failures-to-predict ratio and the fraction of alarm were considered. Results showed that the location of areas of alarm change gradually over consecutive intervals, and no sudden changes can be observed. In addition, the annual changes of areas of alarm are not random and follow a pattern. This study also showed that the modified algorithm having a three to six annual average of events and a 393-km CI radius is an efficient algorithm for predicting the future seismic events in Turkey. This algorithm predicted six out of six target events, retrospectively, with a confidence level of 96.4 %. According to the obtained results, it will be possible to rely on this modified algorithm to predict near future earthquakes of Turkey. Furthermore, this study proves that it is possible to alter the M8 algorithm for being used in regional studies.  相似文献   

A comparison between karst development in two main zones of Iran: case study—Keyno anticline (Zagros Range) and Shotori anticline (Central Iran)     

Manouchehr Chitsazan  Hossein Karimi Vardanjani  Haji Karimi  Abbas Charchi 《Arabian Journal of Geosciences》2015,8(12):10833-10844

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Facies Analysis and Sequence Stratigraphy of Silurian Carbonate Ramps in the Turan (Kopeh-Dagh) and Central Iran Plates with Emphasis on Gondwana Tectonic Event     

Zohreh NOWROUZI  Asadollah MAHBOUBI  Reza MOUSSAVI-HARAMI  Mohammad Hossein MAHMUDY GHARAIE  Farzin GHAEMI 《《地质学报》英文版》2015,89(4):1276-1295

Two sections from the Silurian deposits in the Central Iran Micro and Turan Plates were measured and sampled. These deposits are mostly composed of submarine volcanic rocks, skeletal and non-skeletal limestone, shale and sandstone that were deposited in low to high energy conditions (from tidal flat to deep open marine). According to gradual deepening trend, wide lateral distribution of facies as well as absence of resedimentation deposits, a depositional model of a homoclinal ramp was proposed for these deposits. Field observations and facies distribution indicate that, two depositional sequences were recognized in both sections. These sections show similarities in facies and depositional sequence during the Early Silurian in the area. Although there are some opinions and evidences that demonstrated Paleo-Tethys rifting phase started at the Late Ordovician-Early Silurian, similarities suggest that the Turan and Iran Plates were not completely detached tectonic block during this time, and that their depositional conditions were affected by global sea level changes and tectonic events.  相似文献   

Comparison of linear and nonlinear forms of isotherm models for Zn(II) and Cu(II) sorption on a kaolinite     

Shahram?Shahmohammadi-KalalaghEmail author  Hossein?Babazadeh  Amirhossein?Nazemi 《Arabian Journal of Geosciences》2015,8(1):397-402

The most appropriate method in designing the adsorption systems and assessing the performance of the adsorption systems is to have an idea on adsorption isotherms. Comparison analysis of linear least square method and nonlinear method for estimating the isotherm parameters was made using the experimental equilibrium data of Zn(II) and Cu(II) onto kaolinite. Equilibrium data were fitted to Freundlich, Langmuir, and Redlich–Peterson isotherm equations. In order to confirm the best-fit isotherms for the adsorption system, the data set using the chi-square (χ ²), combined with the values of the determined coefficient (r ²) was analyzed. Nonlinear method was found to be a more appropriate method for estimating the isotherm parameters. The best fitting isotherm was the Langmuir and Redlich–Peterson isotherm. The Redlich–Peterson is a special case of Langmuir when the Redlich–Peterson isotherm constant g was unity. The sorption capacity of kaolinite to uptake metal ions in the increasing order was given by Cu (4.2721 mg/g)?<?Zn (4.6710 mg/g).  相似文献   

Anisotropic behavior of the Bushehr carbonate sand in the Persian Gulf     

Hamed?Farshbaf Aghajani  Hossein?SalehzadehEmail author 《Arabian Journal of Geosciences》2015,8(10):8197-8217

The anisotropy effect is exhibited more prominently in sedimentary depositions, and it relates the soil’s mechanical specifications to the directions of imposed loads. Even though this phenomenon has been comprehensively explored in silica sands, few research has been conducted for studying the anisotropic behavior of marine carbonate sands. To bridge this gap, the present study investigates the anisotropy effect on the mechanical behavior of Bushehr carbonate sand acquired from the north shelf of the Persian Gulf in Iran. Toward this end, some undrained principal stress rotation tests are conducted using a hollow cylinder shear torsional apparatus in such a manner that the direction of the applied principal stresses are fixed along a desired orientation and the total mean stress and intermediate principal stress ratio are kept constant. Furthermore, prior to shearing, the samples are consolidated under three confining pressures and two isotropic and anisotropic states. The results show that dilative behavior is observed in all loading directions after initial contraction; this contradicts the response observed in silica sands. The anisotropy response of soil follows two different trends in the contractive and dilative phases. The relation of soil’s mechanical properties shows a descending trend with the angle of maximum principal stress in the contractive phase; on the other hand, the anisotropy behavior shows a dominant parabola trend in the dilative phase, where the maximum ultimate pore pressure and minimum soil strength occur in the stress direction with an angle of α?=?30°. By increasing the confining pressure in the soil element, the intensity of the anisotropy in some mechanical properties except the soil deformation is reduced. Furthermore, the deviatoric-to-effective mean stress ratio in the phase transformation state from contraction to dilation is independent of the loading direction and consolidation stress state, and it is considered one of the intrinsic properties of sand.  相似文献   

Unsaturated resilient behavior of a natural compacted sand     

Hossein Nowamooz  Cyrille Chazallon  Maria Ioana Arsenie  Pierre Hornych  Farimah Masrouri 《Computers and Geotechnics》2011

Granular materials are generally used in unbound layers of road pavement structures. The mechanical behavior of these materials is widely studied with repeated load triaxial tests (RLTT) in which the elastic response is defined as the resilient behavior. Usually observed under total stress conditions, the effect of pore pressure changes during loading are not usually included in design. Further, the unbound layers frequently exist under partially saturated conditions. The influence of the unsaturated state, i.e., the suction, on the mechanical behavior, of unbound granular materials for roads has not been sufficiently studied and is generally not taken into account in models used for these materials.  相似文献   

Temporal variability of precipitation over Iran: 1966–2005     

Hossein Tabari  Parisa Hosseinzadeh Talaee 《Journal of Hydrology》2011,396(3-4):313-320

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A reconnaissance study of platinum group elements (PGE) contents from sulfide mineralization in pyroxenites in Faryab ophiolite of Iran     

Kaveh Pazand  Firuz Aliniya  Yousef Ghanbari  Hossein Hassani  Nasrin Aghavali 《Arabian Journal of Geosciences》2011,5(5):1021-1029

Platinum group elements (PGE) enrichment occurs in Zn–Cu and Ni-rich ophiolities in a number of geological settings. Platinum group elements (PGE) mineralization in Pyroxenite from the Faryab ophiolities of Zagros belt in south Iran was studied. The ophiolite rocks represent blocks of Tethyan oceanic crust that were emplaced on the continental margin during the late Cretaceous period. Much of lower ophiolitic section is composed of homogeneous harzburgite, while upper sections harzburgite interlayer with dunite and pyroxenite are included. This study focused on pyroxenite that includes most of sulfide mineralization in Faryab. More than 500 samples were investigated from polished thin sections; that cover all area of Faryab. The sulfide phases include pyrrhotite, pentlandite, millerite, violarite, smythite, and heazlewoodite. The results show that in almost all the samples Os is below the 2 ppb detection limit, Platinum values vary from <5 to 91 ppb and the light PGE (Ru, Rh, and Pd) relative to the heavy PGE (Os, Ir, and Pt) are more concentrated. Calculation showed that in pyroxenites Pd–Pt is occurring with orthopyroxenite and Rh–Os is occurring in clinopyroxenite. Ni/Pd ratios in Faryab vary between 7 and 356 and Pd/Ir ratio is 0.1–27. This indicates that in Faryab area partial melt of mantle occurred. Pd/Rh ratio in Faryab is 0.1–11, and Pd/Pt varies between 0.2 and 1.5. Pd/Ir ratio in Faryab decreases and shows that PGE in Faryab occurred.  相似文献