نشریه زمین شناسی کاربردی پیشرفته
سال دهم شماره 35 (بهار 1399)

To study soil quality in Shahid Hashemi Nezhad gas refinery region in view of pollution level of produced sulfur in this industrial unit, 22 soil samples collected from inside and adjacent areas of the refinery. Sulfate content of soil was extracted in three phases water soluble, absorbed, and occluded with carbonates by deionized water, 0.032 M NaH2PO4 and 1 M HCl, respectively. The concentration of total sulfate was determined by soil complete digestion with a mixture of HF, HCl and HNO3. The content of organic matter and CO32- and HCO3- anions concentrations in the soil samples were measured using titration method. Organic, occluded with carbonates, water soluble and absorbed sulfate had the maximum concentration in the soil samples respectively, that inside refinery samples had more concentration than the other samples regarding all these phases. Water soluble sulfate had a reverse correlation with soil pH that showed sulfate occurrence could slightly oxidize sulfur and its compounds and acidic environment dominance in the soil.

The effects of freezing-thawing cycles on the compressional wave velocities and dry density of schist rock have been investigated in this research. For this purpose, 13 boreholes were drilled in the Angouran mine and 25 cylindrical specimens were prepared. Then, the samples were weathered in the laboratory by freezing-thawing process and the compressional wave velocity and dry density of samples were measured in freeze-thaw cycles of 0, 7, 15, 40 and 75. The results analysis indicates an exponentially decrease in the compressional wave velocities (50% reduction) and dry density (30% reduction) with increasing the number of freeze-thaw cycles. Also, wave velocities exponentially increased with increasing the dry density. By fitting the concluded results, two empirical equations to calculate the compressional wave velocity and dry density in schist rock for different numbers of freeze-thaw cycles and also an equation between compressional wave velocity and dry density have been presented. In addition, the texture of samples was studied in intact situation and after 75 cycles of freezing-thawing by an electronic microscope. The obtained results indicated that the samples texture is condensed before weathering, whereas the discontinuities spacing is increased after weathering. Finally, verification results proved that there is a good conformity between the outputs of current study and other investigations.

In this study, climatological, geological, hydrogeological and geophysical investigations were carried out in order to assess the environmental suitability of a waste landfill located 13 km southwest of Zanjan. Achieving this aim was based on developing a GIS-based model, geoelectrical surveying and the measurement of infiltration rate using a double-ring infiltrometer in the landfill. The assessment of the vulnerability of the aquifer to pollution showed that the landfill is situated in a moderate vulnerable area. Double ring permeability tests confirm the landfill is an acceptable site showing a relatively low permeability rate. In this study, using ten vertical electrical soundings in Schlumberger array, it is shown that the electrical resistivity of deposits in the landfill varies from 20-35 Ω-m for fresh and wet dumps to 120-200 Ω-m for dry and old dumps. The leachate plume has a width of about one km and spreads to a depth of about 55 m. The shape of the plume shows the leachate migration is towards the northeast. Considering the estimated groundwater depth at more than 86 m and calculated infiltration rate equal to 1.95 mm/hour, it can be concluded that the contaminant plume will not reach the water table up to 2024.

Increasing the concentration of greenhouse gases leads to global warming is a phenomenon called resonance phenomenon that has led to an average annual temperature of 0.74 ° C over the last century the Earth's surface to rise. Global warming is a phenomenon that many adverse effects on human life and affects animals. Find phenomena such as droughts and intensity of rainfall . What reduction - Increased occurrence of dust and Sylabha.nyz days of climate change caused by global warming in the world ultimately was. In this study, to investigate the phenomenon of global warming in the province using the usual methods of time series (moving averages, trend-factor equation Trendline) and Mann-Kendall test, the average annual air temperature changes over the period 2016-1988 to 8 stations synoptic meteorology (Ahvaz, Abadan and Dezful Bustan- omydyeh- Ramhormoz-Mahshahr-MasjedSoleiman)is examined. The results obtained indicate a significant increase in average temperature of the air at all stations in the province so that the selected stations during the study period (except station in Masjed Soleyman, rising at 5% level) show the significant increase in the level of 1% of the stations 0.107 and 0.097, respectively Vramhrmz take degrees Celsius per year, the highest annual rate of increase in temperature have had

Mashayekh area is located in Charmahal and Bakhtiari province and is structurally located in the high Zagros belt. This region is characterized by two mining districts, namely, the Dehmadan and the Darreh-Yas, approximately two kilometers apart. The most mineralization is associated with organic-bearing carbonate rocks in the Dehmadan deposit. The presence of Do-ab salt dome and Ab-Vanak reverse fault in around of the study area have been resulted in changing the salinity, Eh, pH and movement of ore forming fluids. The geochemical results represent negative Ce and Eu anomalies, Light Rare Earth elements (LREE) enrichment relative to Heavy Rare Earth Elements (HREE) in the Dehmadan deposit that the features are analogous to that of central African Zambian belt sedimentary copper deposits. Darreh-Yas deposit also shows weak negative Ce anomaly and HREE enrichment relative to LREE. In general, the results indicate that metals of old units have been leached by high saline brines with oxic conditions and entered into sedimentary basins. Then, the reaction of ore-forming fluid with organic-bearing carbonate rocks lead to ore deposition in a reduced condition. Finally, the ore has been undergone by late-stage supergene and weathering processes.

Sinkholes are more abundant, in the quaternary-covered basins with soluble bedrock. In the folded Zagros in Iran, the Most of plains are karstic. This research was carried out in an area of 155 km2 in location of old the Jaydar and the Gori Balmak lakes, in south of Poldokhtar city, SW Iran. The purpose of this study was to evaluate the factors affecting the formation of sinkhole. In this area are expanding lake sediments of the Seymareh landslide dams. The thickness of lake sediments have been estimated using geophysical studies include GPR with 10 MHz antenna and ERT, respectively an average 70 m and less than 10 m in the Jaydar and Gori Balmak plains. The bedrock of study area is the Gachsaran Formation (Middle Miocene) includes gypsum massive and marl. Uniaxial compressive strength (UCS) and tensile strength of gypsum section of bedrock is respectively 16.39 and 1.5 MPa. At least 4 joint sets are expanded in the bedrock. The source of the filling materials of the joints is eroded marl units of Gachsaran Formation and lake sediments. The dispersion of joints filling material is approved by Crumb, dual hydrometer and chemical tests. The dual consolidation test showed that the covering sediments of bed rock are collapsible. Pezometric data show that the average depth of groundwater in the past 10 years has loss about 3 m and lies at a depth of 20 m at ground level now. Field observations show less than 32 sinkholes in the study area

The geomechanical and petrophysical parameters of the reservoir such as shear wave velocity, porosity and permeability are regarded as the most important elements in estimating reserves, reservoir simulation, and overall field exploitation strategies. Recently, several methods of artificial intelligence techniques have been used to predict this parameter by using well log data. However, predicting the characteristics of heterogeneous reservoirs always has been facing many problems and an appropriate response is rarely achieved. In this paper, a new methodology is presented for reservoir parameters (shear wave velocity, porosity and permeability) estimation by combining artificial neural network and Particle Swarm optimization (PSO) in Asmari formation of mansuri oilfield. Performance of proposed hybrid scheme was evaluated by comparing the results with the Neural Network and Nero-Fuzzy methods as well as hybrid genetic algorithm–neural network strategy (GA–NN). Comparison of the results shows that PSO-ANN outperforms all the other methods and it can be considered as a powerful tool for reservoir parameters estimation, especially in cases where a precise estimation criterion is crucial.

One of the main purposes of geological remote sensing is trying to improve mapping methods of various rock and minerals. In recent decades, with the development of Remote Sensing, this technology has been proposed as an effective method for mapping of rock units. remote Sensing technology has been very helpful by using satellite data to control and monitor various pollutions in managing different sources and also its economical to use these data to identify enviromental pollution caused by unlimited mining activities and with fast detection of these kind of pollution, it has been very useful for solving enviromental problems. Undoubtedly the use of this technology in exploratory studies, natural and environmental resources not only increases the speed of studies, but is also much more efficient in terms of accuracy and cost and manpower. The purpose of this study is mine tailings detection of the Anguran Pb-Zn mining area using false color combination (R:1,G:6,B:3), principal component analysis (PCA), and band ratios [R3/2,G5/3,B8/4]. The use of the first three PC and the evaluation of the eigenvector shows that the fifth and ninth components with eigenvectors of 0.72 and 0.65 indicate the spectral behavior of carbonate and clay minerals in bands 8 and 6. image processings validated by the USGS library spectra, the Resampled USGS library spectra and Z-Profile images.