فهرست مطالب رمضان رمضانی اومالی

The Nekarood basin is located in the north of Iran and has an area of 2275 km2. In the Nekarood Basin, the majority of limestones include thick bedded and massive limestones of Lar and Cretaceous limestones, and there is also a lesser amount of Elika, Dalichai and Ruteh limestones. Various features such as the amount of outcrop, thickness and lithological characteristics of karst rocks and their relationship to other lithologies on a regional scale are the geological controls on karst development. Among these factors, the thickness and lithology of the existing formations in the studied area are of great importance, in such a way that if the outcropping limestone is thick bedded and massive, the karstification process is very high. The stratigraphy of the region and the spread of The Lar limestones in the region are among the reasons for the dominance of the conduit flow system in this basin. Stratigraphy has an effective role in the development of karst and the spatial distribution of the amount of recharge in the formations of the studied area, and by considering the effect of factors affecting recharge using GIS and remote sensing, the status of the hydrogeological budget of karst in the region is investigated. Estimating the amount of recharge is also one of the most important parameters in hydrogeological studies for calculating the budget. The recharge potential map was prepared using several layers of information, including lithology, slope, aspect, density of streams, precipitation, density of fractures and epikarst, after weighting by expert method and integrating information in the Geographic Information System (GIS) environment. According to the obtained results, the desired area is divided into five sections with 12, 20, 28, 36 and 48% recharge potential, and the corresponding area of each section is 50, 360, 877,817, and 5 km2, respectively. The average recharge in the whole range was estimated to be about 29%. Based on the amount of recharge and average annual precipitation (430 mm), the total amount of recharge in the Nekarood karst basin is estimated to be about 261 million cubic meters (MCM), of which about 64 MCMis discharged by springs and wells in the karst basin, so the annual discharge volume in this area is more than the annual discharge volume of about 197 MCM. Considering the location of the Nekarood karst basin near the Caspian Sea and the existence of faults in this area, it can be stated that, most likely, part of the water recharge in this basin is discharged to the sea.

Dochileh copper deposit is located 72 km east of Shahrood, 15 km east of Mayamey, in North Central Iran volcanic belt. The stratigraphic sequence of the region comprises a considerable amount of volcanic and volcanic-sedimentary deposits of Eocene. these deposits are locally covered by Neogen and Quaternary deposits. The volcanic rocks hosting mineralization are composed of different rocks including basalt, andesite basalt and trachy andesitebasalt rocks that often contain plagioclase and clinopyroxene phenocrysts. The copper mineralization mostly occurred along the faults and fractures with the dominant trend of NW-SE in the basaltic rocks as vein-veinlets and open space fillings. Ore minerals including primary native copper and hematite, and secondary minerals such as malachite, goethite, hematite. gangue minerals such as calcite, zeolite and analcime. The wallrock alterations in the host rocks include chloritic, carbonatic, analcime-zeolite and iron oxide. The oxidation of mafic minerals such as pyroxene and magnetite were responsible for copper reduction and hematitic alteration. Geochemical investigation indicates that amounts of Cu and Ag are up to 5.11 wt% and 7.8 ppm, respectively. According to field studies, mineralogy and alteration, the Duchileh copper deposit appears to be formed during diagenesis and burial metamorphism, and dominantly during the orogeny and uplift processes, due to enterance of hot ore fluids along the fractures and faults perpendicular to the fold axis. The Duchileh deposit have a large resemblance to the basaltic copper or Michigan-type copper deposits in terms of tectonic setting, host rock, mineralogy, metal content, alteration and ore controls.

Miamei city is located in the east of Semnan province and It is important to seismic study because of proximity to the active Miamei Fault and recorded seismic events. Miamei, Hokmabad and Armian Faults are more importance for Seismic sources around Miamei city. In this research two methods (Gutenberg-Richter and Kijko-Selevoll methods) have been used for seismic statistical studies. Statistic studies based on Gutenberg-Richter show a 100 years return period for an earthquake with magnitude 6.5 Richter. Also based on Kijko-Selevoll show a 100 years return period for an earthquake with magnitude 5.9 Richter tat statistically has more coincide with actual events. The results of probabilistic seismic hazard analysis around the Miamei city at a radios 150 km indicate maximum horizontal acceleration of 0.7g in a 475 years return period. In this zoning, Miamei city is located in horizontal acceleration of 0.3g-0.4g which can be considered as a city with high seismic hazard class in area.

In the past decade, several geophysical, geological and reservoir studies have been done on the Qom formation in the Yortesha field for injection and gas storage purposes. Qom formation in this field has a poor reservoir characteristic (low porosity and permeability); therefore the role of fractures for increasing permeability and improving reservoir quality is very important. In the current study, fractures’ concentration and strike patterns of the Qom and Upper Red formations as the carbonate reservoir and cap rock, respectively, have been investigated and compared in the Yortesha anticline and its adjacent anticlines (Davazdah Emam and Morreh) using surface and subsurface investigations. In order to achieve this goal, desert data gathering methods, remote sensing, and image log analysis have been used. Subsurface studies and interpretation of FMS and EMI image logs determined that fractures have also a secondary strike of NE-SW in addition to strike of NW-SE. Based on the FMS image log interpretation of well No. 2, three subsurface fracture sets have been identified with the strikes of N55E, N65E, and N15W as well as using the EMI log of well No. 4 shows the two dominant strike of N10E and S45E. The total 1852 specified fractures in the out crops of the Morreh and Davazdah Emam surface anticlines can lead to rose diagrams that show four fracture sets with the strikes of N10E, N45E, N80E, and S45E.

Burkh anticline with the WNW-ESE trending is located in southeastern part of the Zagros fold-and-thrust belt and 40 km to the north of Bastak in the Fars zone. In this paper, based on the field data, satellite images and construction of the seven structural cross sections, structural geometry of the Burkh anticline is presented. Presence of the Precambrian- Cambrian of the Hormoz salt Formation as a basic detachment layer decouple the folded sedimentary cover from basement. Structural data show that the Burkh anticline is a detachment, buckle, asymmetrical and disharmonic fold. For describing tightness geometry of the fold, the term “open” is suggested. Field study and structural cross sections show that the Dashtak Formation as a middle detachment layer is the controlling factor for development of small-scale folding. Based on top of the Dehram Group underground contour map, vertical closure about 1000 m and horizontal closure of 200 km2 were calculated.

Zafarghand granitoid pluton with compositional range from gabbro to granite and early to middle Miocene age cropped out in the 35 km of SE Ardestan. This pluton intruded in the Eocene volcanic and volcanosedimentary rocks of Urumieh - Dokhtar structural zone. In this research, for the first time, emplacement mechanism of Zafarghand granitoid pluton method has been investigated by using of anisotropy of magnetic susceptibility (AMS). Based on the field observations, petrography and interpretations of magnetic parameters Zafarghand pluton divided into 5 domains (1A, 1B, 2, 3 4 and 5). At first, 2 and 4 domains have been emplaced. They have lithological composition from gabbro to quartzdiorite and played role such as feeder zones. Then 1A, 1B, 3 and 5 domains by dominantly granodioritic – granitic composition have been emplaced such as a big sill or low dip magma flow. It is should be mentioned that during emplacement of this pluton, fractional crystallization, magma mixing and crustal contamination participated in its generation and evolution.

Rock falls are the usual forms of slope instability in hill slopes. The high velocity and rapid occurrence are the main differences of rock fall and other rock instability. Therefore, the rock falls are among the most destructive mass movements and results in high loss of lives and heavy damage to the structures, roads, residential area, farms and etc. In this research, rock fall in rocky slopes of the Tepal Mountain in northwest of Shahrood city was investigated. For this, the large scale geological map of area (scale of 1:10000) was produced and joint studies in 12 sections performed. Then, the slope instability was analyzed by two methods of stereographic (using Dips 5.103 software) and analytical method (by Swedge 4.078 and rock fall 4.039 softwares). The results show that all of the slopes are stable in static conditions and become instable in dynamic state. In critical states of huge raining and earthquake intense instability will be occurred and the big problems could be created for the down area of slopes. Based on the results of analytical and using the Arc GIS 9.3 rock fall hazard zonation map was produced. In addition, by overlaying of landslide hazard map and land use map, the area affected by rock falls was distinguished. The results of this study show that Salamaty road, Mazar Shohaday Gomnam and its access road, some part of Azadi Park, the tourism hotel, some of the residential area down of the Salamaty road and some parts of the Abshar Park are located in the hazard zones.

In this study active faults in the region of Shahid Rajai dam of sari with 100 km radius was categorized on based fractal dimension of faulting and Earthquake and also evaluating of slip rate and investigate those activity rate. Using the fractal dimension of faulting and earthquake with squares method (Box-counting) and finally by classification this fractals dimension، the faults of North Alborz، Damghan and Garmsar more activity faults in the region of study area during 100 years late which based on activity degree of faulting and Earthquake with method of fractal analysis which based on assessment of activity degree of faulting and earthquake with method of fractal analysis also set in BD grade and this activity was confirmation. For assessment of slip rate beginning the seismicity parameters (a&b) of study area was determination، then these parameters were normalized for each fault. Based on existing relationships and having a&b for each fault، the seismic moment those fault was calculated. According to The relationships for calculating the rate of seismic moment، slip rate of each fault has been estimate and based on faults in study area was classification. The Faults with very low slip rate and high return period of earthquake could cause occurrence large earhquakes which earthquake of 856 A. D Qumes and causing smith therefore Damghan Fault could this fault know. Thereupon Therefore expectance larger slip in the future on faults such as Astaneh، Rameh، Cheshme-Ali and etc Will have. High slip rate along the New faults introduced (Khorram-Abad، Majid، etc.) in this area is noteworthy that according to occurrence the earthquakes in the privacy of their fault، the high slip rate is reasonable.

The Minab (Esteghlal) dam site is located in east of Minab city in Hormozgan province and in the vicinity of active fault of Minab. Joint studies in the ten stations on the rocks masses around the reservoir of dam demonstrations the four main joint sets. For assessment of this idea، the permeability of rock masses outcrops in the reservoir is estimated by HC experimental model. For this، the RQD، GSI and other characteristics of discontinuities in rocky outcrops in dam reservoir are measured in field studies. The results show that the permeability of left and rock dam embankments change from 9. 14 × 10-6 up to 2. 02 × 10-5 m/s. Also the water lost for three different condition of minimum، mean and maximum level of water table are 0. 14، 0. 20 and 0. 29 m3/s. The results indicate that the discontinuities with trend of east – west and northeast – southwest and also shear fault zone of Minab have main effects in leakage of reservoir