مجله پژوهش های دانش زمین
پیاپی 30 (تابستان 1396)

The studied volcanic association is located in the Orumieh- Dokhtar magmatic belt (North of Saveh) and includes andesite-basalt, trachyte- andesite and dacite. The rocks are predominantly Late Eocene in age. Geochemically, the rocks show calk-alkaline and less abundant alkaline signatures. The samples show LREE/HREE enrichment with (La/Yb)N, (Sm/Yb)N and (La/Sm)N ratios of 2.93- 10.27, 1.58- 2.16 and 1.79- 4.57, respectively. Based on Harker diagrams as well as geochemical modeling, magmatic differentiation process is not able to explain all the magmatic variations and supports the presence of distinct genetically unrelated rock suites. Although some of volcanic suites may be derived by fractional crystallization process from more mafic ones. Trace element geochemical modeling suggests that the dacites can be derived as

In South and West Lut block, Dynamic parameters from the earthquakes and geodetic moment rate obtained, during years 2006 to 2015, indicates, in this area seismic and interseismic deformation and risk of seismicity are too much. In this study, the frequency range of 28 earthquakes with magnitudes MN≥4.5 is studing. By study more than 280 suitable frequency records of earthquakes, dynamic parameters of the earthquakes, for example source dimension, scalar moment, P and S corner frequencies, dynamic parameter of stress drop and moment magnitude, that are important in seismology, are calculated and processed. According to our calculations, moment magnitude (Mw) is between 3.7 to 6.4, seismic moment is between 4.16869E 14 (Nm) to 5.01187E 18 (Nm), stress drop is between 13.94 (Bar) to 331.08 (Bar), corner frequency of P, S are 0.33 (HZ) to 3.02 (HZ) and the width of the crust that has been broken is 0.42 (Km) to 5.99 (Km). In study area, most of stress drop is 331.08. This stress drop is related to Reagan's earthquake that occurred in date 2011.01.27 with Mw = 6.4 on the southern branch of Kahorak fault zone. The stress drop of this earthquake is much higher than the average of 27 other earthquakes (97.9Bar). Geodetic moment rate in the region is between 6E Nm.yr to 7.75E 17 Nm.yr. In the last decade, in parts of area that geodetic moment rate are higher, stress drop is less. In other words, in these areas (areas with slow strain) energy is not free suddenly.It is free slowly. For study area in recent decades, the rate of seismic moment is 7.42557E 17 Nm.y and geodetic moment rate is 6.44E 18 Nm.yr. In the study area, relationship between moment magnitude (Mw) and seismic moment logarithm (Log (m0)), relationship between seismic moment logarithm with Broken zone (Sr) in the earthquake, relationship between the Broken zone and the slip in the spring of each earthquake (Ss) and relationship between spring of each earthquake and stress drop are respectively Mw=0.600Log(m0)-5.054, Log (m0)=0.643Sr .47, Sr=0.013Ss .869, Ss=0.673St -31.59.

Structural examination of the southern part of the Kerman Cu belt revealed the structural linkage between the lineaments and the distribution of the Cu deposits and prospects in this area. Surveying the linear structures of the region indicates that the studied linear structures can be divided into three broad groups, including: 1) the crustal scale lineaments controlling the regional distribution of the large Cu ore deposits, 2) the large lineaments following the general and the regional tectonic NW-SE trends controlling the distribution of the Cu deposits, also, the large stratovolcanoes, and 3) the linear structures identified by several characteristics including the more sporadically distributed patterns, shorter lengths and diversified patterns. Quantification of the proposed relationship through application of the photolineament factor (PF), and therefore, using the obtained contours on the compiled map showed that 20 of 34 Cu deposits and prospects fall on the areas with PF≥3. The other deposits or prospects fall outside the drown contours. All the recent characteristics indicate the third group to be similar to surficial fractures. The areas showing high concentration of these linear structural forms seem to be affected by hydrothermal alteration activities. Traces of the intruded subvolcanic bodies are also identified at the intersection of some of these linear structures. The achieved results indicate that although the linear structures seem to control the localization of the Cu deposits and prospects in local scales, but the discussed localization also seem to be controlled by another regional scale structural forms, outside the scope of this paper.

The tectonic setting of Iran during late Neoproterozoic time is not fully understood, with proposals ranging from passive margin (Iran as a part of Afro-Arabian platform) to active margin (Iran as a part of Peri-Gondwanan terranes). Tectonic provenance of Bayandor Formation, which is deposited during this time, can provide constraints on late Neoproterozoic tectonic evolution of Iran. The Bayandor Formation in the Chopoghlu section is mainly composed of dark purple to red siliciclastics, mainly mudrocks and minor sandstones (~400m). The sandstones contain abundant quartz, volcanic lithic fragments (mainly andesite and rhyolite), and feldspars and have an average composition of Q44F30RF26 (lithic arkose to arkosic litharenite), Qt47F30L23 and Qm37F30Lt33. The data presented here clearly indicate that the Bayandor sandstones were derived from magmatic arc sources dominated by relatively felsic/intermediate volcanic rocks and unroofed granodiorite intrusives. Textural and compositional immaturity of Bayandor sediments, along with sub-angular to angular shapes of labile grains such as volcanic rock fragments, suggest local derivation from surrounding exposed basement (proximal sources), and deposition on an active continental margin. These results provide new constraints on subduction scenario during this time interval in Iran, as a part of the Peri-Gondwanan terranes.

In hydrogeochemical exploration, the association of elements usually are studied in parallel and prepared their distribution map in order to identify probable anomalies. To do this in Kadkan region, 110 underground water samples are analyzed and R-factor method is applied to identify element distribution. Finally, after statistical processing and determining the number of different factors, 6-factor model was selected, constituting 69.72% total of data variance and reflecting most coincidence with lithological, hydrochemical unites and potential parts of probable mineralization of uranium in region. For determination of anomalies, Factor scores of all data related to region were calculated. Based on this calculation, mineralization factor (4) has strong positive loadings for the uranium, sulfur, molybdenum, selenium elements and fluoride, phosphate, sulphate ion. These elements are the traces elements of uranium deposits, so, can indicate the possible zones of uranium mineralization.

Soil temperature is the most important factor in sustainable development and agriculture. These factors are not controllable, but by examining the facts and figures it can be predictable and under control. The aim of this study was to evaluate soil temperature at synoptic stations in Sari, Mazandaran province. The study period is from 2003 to 2014. The database consisted of soil temperature at depths of 5, 10, 20, 30, 50 and 100 cm, dry air temperature, soil moisture and air in the above-mentioned period which is collected by the equipment used in meteorological stations. Neural network method is used to estimate the model. Results showed that soil temperature is directly related to air temperature But deep down near the surface of this dependency has been.and Soil temperature with air humidity has fluctuates. So that up to 50 cm rise but decreased with increasing depth. Soil moisture also examined and The results have shown that this agent is effective in high depths.

Climate is one of the most important environmental factors that impact human life and activities. Therefore, it is important to know about climate zones for planning and spatial development of different reigns. The main purpose of this research is zoning the temperature of Iran using fuzzy clustering. Data about mean of daily dry temperature, maximum temperature, minimum temperature, dew point temperature and wet temperature of 63 synoptic stations in Iran were collected from meteorology office during 1989 to 2013. Data were reduced in MATLAB software using SVD method and clustered using fuzzy clustering. Results indicate 6 temperature clusters in Iran. Temperature zoning of Iran is affected by the Caspian Sea, Persian Gulf, Oman Sea, Alborz and Zagros mountain ridges, and internal areas of Iran.

Ardebil City is one of the high-risk points in terms of earthquake incidence potential in Iran. This matter is a serious threat for sustainability of development of this city. The objective of this study is measurement of degree of the city’s resilience against the risk of earthquake incidence. This research is of descriptive-analytical type with a practical aim. Accordingly, the city’s resilience is evaluated based on 14 criteria in the form of 4 main elements with Delphi method with the help of 50 experts. For data analysis, one-sample t-test, Friedman, Kendal, and Route analysis were used inSPSSSoftware. The findings of the study indicate that the status of Ardebil’s resilience against incidence of a probable earthquake in sum of the elements is undesirable with a mean of 3.33. Furthermore, the degree of city’s resilience during and after incidence of earthquake is far lower and significant at 95% level. From among the four elements, the skeletal element with total direct and indirect effect accounts for 56.5% of the alpha and thus is the most effective element in Ardebil’s resilience. The four dimensions of resilience in total were able to account for 74.9% of the Ardebil’s resilience. At the end and based on the research findings within 4 main elements, a number of suggestions are presented for making the city resilable against the risks of incidence of probable earthquakes in Ardebil.

This study aimed to develop and evaluate the accuracy of equations to calculate degree days using the average daily air temperature is wrote. In order to the beginning, calculate the heating degree days ( ) and cooling ( ) of output Asfazari database using two models, and considering the brink of the United States of America was used Standards Association. In order to relationship the need for heating and cooling stepwise multiple linear regression method with the country of cubic and quadratic equations were used. The results showed that quadratic function is much more accurate than predictions cubic function for heating and cooling needs with a standard deviation 0/328 and 0/370 from. The beta coefficient ( ) and indicates that except for the constant in the equation , factor temperature with an average three lies more important than other factors are input to models for heating needs. As well as for be cooling needs of an average air temperature is more important than other factors. Calculate the combined standard deviation , latitude and altitude increased the accuracy of prediction model that represents the spatial variation of these parameters and alignment of multilateral environmental factors. Spatial analysis requires several characteristic heating and cooling climate for this parameter in the territory of Iran is evident: 1. implantation weather in the form of climatic zones; (2) require high spatial variation uneven heating and cooling arrangement and sharp changes in elevation.

Drought is a recurrent phenomenon in different climates. The occurrence of this phenomenon is not limited solely to the arid and semi-arid climates, but also occurs in climates humid and very wet. In this study, using data from annual precipitation 31 stations in the period (2015-1986), After complete homogeneity and process data deficiencies , the values of different profiles (SIAP, SPI, RAL, PNPI and Z Score) software in DIP and DIC were calculated and severe drought in the South and South West of Iran were identified. Required data received from the site http://www.esrl.noaa.gov and then in 1000 to 700 hPa levels synoptic maps outlining the core Saudi Arabia subtropical high pressure centers in the daily and monthly levels were above hPa. Synoptic analysis of data for drought pattern lengths ranging from -60 ° west to 100 ° east and latitude of zero (equator) to 80 ° north and software environment ARCGIS10.3 selected as the map was drawn. As well as the position of the jet stream in severe drought with script creation software and the core jet stream axis GRADS drawing and drawn. The dominant pattern of severe drought the region has been analyzed. The results showed that the severe drought in the region of the Azores anticyclone system tongues of four, Africa, Saudi Arabia and Siberian in a circuit line widths in the range of 15 to 45 ° north merged and for the entire region encompasses a wide belt. Saudi pressure quite moving West ward and throughout the period of precipitation on land is the Arabian Peninsula and integration with high pressure tripped Africa pushing low pressure Sudan to prevent its spread to the southern latitudes and high latitudes is and moves West ward cell with Saudi, Subtropical jet stream has moved West ward and the North East Africa.