نشریه علوم زمین
پیاپی 90 (زمستان 1392)

The purpose of this paper is to analyze geological samples (water) using cartridge in order to pre- concentration of these samples. In this paper, the study of Uranium ion imprinted polymer (IIP) synthesis is addressed. The Uranium ion complex in (CH3Coo)2 Uo2. 2H2O is considered as the initial nucleus of polymer. This complex is formed by di vinyl phosphonic acid (VIP) ligand. Then, ethylene glycol dimethacrylate (EGDMA) is used as cross linker and azobis isobutyronitril (AIBN) acting as initiator in polymerization is applied for the final synthesis of polymer. The synthesis of these polymers is performed by covalent interactions. The complex of non- imprinted polymer (NIP) is also synthesized under above- mentioned condition but without the presence of Uranium ion and ligand. IIP was obtained can be used as a high absorbent for solid phase extraction (IIP-SPE). In addition, the study of condition andtests such as pH effect on absorption, permeability factor, acid concentration and volume which is required for elution is conducted in order to test the column efficiency. The experimental evidences indicate that the maximum absorption of Uranium ion is in pH= 7. In addition, 1M nitric acid solution with 5 ml volume has the highest elution rate. The rate of uranium permeation was measured above 200 mm. The results were obtained by ICP-MS as reference and ICP-OES to promote the analytical reading and reduce the detection limit. These results indicate very high absorption of IIP for Uranium ions. It must be noted that this process was successfully applied for pre-concentration of geological samples, inparticular water samples and led to the promotion of results from analyzing all metallic ions such as uranium ion in geological samples (water) by ICP-OES and analytical optimization with lower detection limit by ICP-MS.

Various types of volcanogenic massive sulfide (VMS) deposits occurred within the northern and southern parts of the Sanandaj-Sirjan zone (SSZ). The most important VMS deposits of the south SSZ includes the Bavanat Cu-Zn Ag (pelitic mafic- or Besshi-type), Sargaz Cu-Zn (bimodal mafic- or Noranda-type), and Chahgaz Zn-Pb-Cu (silicicalstic felsic-or Bathurst type) deposits, and the north SSZ hosts the Barika gold-rich (bimodal felsic- or Kuroko-type) VMS deposit. Comparison of the VMS deposits, and investigating of possible relationship between formation of these deposits and tectono-magmatic processes within the SSZ indicate formation of all the deposits within intra-arc rift basins related to subduction of the Neo-Tethyan oceanic crust beneath the Iranian plate during Mesozoic period. Main reasons for formation of the different VMS types within the SSZ might be due to evolution of magma nature and intra arc rift basins. Comparison between the deposits in many aspects including host and associated rock types and ore mineral paragenesis indicate clear differences between the Bavanat and Sargaz deposits and the Chahgaz deposit. It is inferred that the differences could be due to variations in magma compositions, i.e., felsic in the Chahgaz, and mafic in the Bavanat and Sargaz host sequences. Indeed, development of the intra-arc rifting was at early/nascent stage in the Bavanat and Sargaz regions and at mature stage in the Chahgaz area. The SSZ (particularly the southern part) due to hosting various VMS type deposits and involving the known largest and majority VMS deposits in Iran is the most attractive structural zone for VMS exploration.

This study investigates the organic petrographic of the upper Triassic to Lower Jurassic Olang coal deposits. Olang area is located in 70 km of northeast Shahroud. This area is situated in Gheshlagh Olang synclinal which is a member of eastern Alborz coal basin. Microscopic studies showed that all three maceral groups of vitrinite, inertinite and liptinite presented in coal deposits of the Olang region and the vitrinite is most important maceral group in these coals. Macerals of vitrinite group include colotelinite, collodetrinite and corpogelinit that collodetrinite is the most abundant of maceral in coal deposits. All of inertinite macerals group observed in these coals which Semifusinite and fusinite are the most abundant in this group. Spornite, cutinite, resinite and lipthodetrinite macerals of liptinite group are present in the coals. Abundance of collodetrinite, presentation of fnginite and the absence of tellinite in these coals are usually thought to indicate deposition in neutral to weakly alkaline waters in an oxygen-rich environment.

In the aim of petroleum exploration at Qum area, gravity and magnetic measurements incorporating 2059 measuring stations have been conducted in order to detect likely buried oil traps, any volcanic intrusive, faults and subsurface folding related to the Qum formation. Bouguer and total magnetic anomaly maps were produced when the required corrections were made on the gravity and magnet data. The fractal method incorporating intensity-area model was used to produce residual gravity and magnetic maps. These maps were compared with those maps produced by trend surface analytical method and then interpreted. The results obtained by the interpretation show that although the presence of an anticline which was determined using gravity method is important for petroleum exploration; however, the magnetic intensity is very high on a part of this anomaly. Furthermore, it is probably affected by the surrounding faults. The results obtained in this study can be effectively used to decide doing further exploration works in the study area.

Ghareh-bolagh area is located in 20 Km of east of Mahabad, south of West-Azarbaidjan province. Carbonate rocks of Bayandour formation and dolomites of Soltanieh formation in this area are the host of mineralizations for Barium, iron and manganese. Based upon mineralogical investigations, barite, magnetite, hematite, goethite, limonite, pyrolusite were major mineral assemblages of these mineralizations which that is accompanied by chalcopyrite, malachite, azurite, and calcite in low amounts. The most important geochemical characteristic these mineralizations are relative weak differentiation of LREE from HREE in barite and iron-manganese ores, Eu negative anomalies in iron-manganese ores (0.26-0.76) and Eu positive anomalies in barite (7.7-10.51). Incorporation of the obtained results from investigations of field, petrographic and geochemical (analytic data and correlation coefficients between elements) indicate that factors such as changes in physicochemical conditions of environment (pH, Eh, temperature), activity of complexing ligands, and presence of minor mineral phases (clay minerals, zircon, zenotime, and monazite) played important role in distribution of rare earth elements during mineralization and development of these ores.

Temporal and geometrical decorrelation often prevents SAR conventional interferometry from being an operational tool for surface deformation monitoring. Persistent Scatterer Interferometry (PSI) techniques presented to overcome the limitation of SAR conventional interferometry and use amplitude analysis and considering temporal deformation model for PS pixel selection fail to identify PS pixels in rural areas lacking man-made structures. On the other hand, the high subsidence rates lead to not be fulfilled the required condition for unwrapping (Nyquist sampling criterion) and significant phase unwrapping errors in novel PSI algorithm (StaMPS) that applies amplitude analysis as well as phase stability in order to select the PS pixels without using a pre-define deformation model. Therefore, in this paper we present an enhanced algorithm based on PSI in order to estimate deformation rate in rural area undergoing high and nearly constant deformation rate using the available SAR images. The proposed approach integrates the merits of all existing PSI algorithms in PS pixel selection and phase unwrapping. PS pixels are selected based on the amplitude information and phase stability and their phase are compensated for APS and nonlinear deformation contribution by applying temporal filter. Deformation rate is then estimated using LAMBDA method that is a fast and optimal without considering Niquist sampling criterion. The approach was applied to the ENVISAT ASAR images of Southwestern Tehran basin and the results were evaluated with leveling data and the maximum difference rate across the leveling stations was 5 cm/yr demonstrating the high performance of the proposed algorithm in comparison with the obtained results from other interferometry methods. Moreover, the presented algorithm was applied to the simulated data and the value of RMSE was obtained 0.003 m/yr confirming this success.

Shoghan plain is one of the sub-catchments of the central Kavir, in North Khorasan Province which experiences semi-arid to arid climate. With the exception of its eastern part, the quality of water in Shoghan aquifer is very low, unacceptable even for agricultural use. One of the main factors that deteriorate the quality of groundwater is local geology which comprises mostly sedimentary rocks and in particular evaporites. In order to study the effects of geological formations on the quality of groundwater, 31 water samples were collected from different parts of the aquifer in 2009 and were analyzed for acidity, electrical conductivity and major ions. In the second step, ion distribution maps were prepared and geological characteristics were rechecked in the field. These show that geology plays a significant role in the distribution of ions. A combination of ions cross plots and saturation indices of gypsum, halite, calcite and dolomite minerals show that the dissolution of these minerals and weathering of silicate minerals is commonplace in the aquifer. Due to high concentrations of sodium in the groundwater of the area, reverse ion exchange is one of the chemical processes controlling the chemical composition of groundwater.

Quaternary volcanic rocks are widely developed in NW of Ahar, NW Iran. Based on geochemical data, these rocks mainly consist of alkali basalts, trachybasalts, basaltic trachyandesites and trachyandesites. The major- and trace-element chemistry indicates that the lavas are dominantly alkaline in character. The studied rocks display microlithic porphyritic texture with phenocrysts of olivine, clinopyroxene, and plagioclase ± amphibole ± biotite. Major and trace element abundances vary along continuous trends of increasing SiO2, Al2O3, K2O, Na2O, Ba and Rb decreasing CaO, Fe2O3 * and Cr with decreasing MgO.The volcanic rocks in this area are characterized by the LILE and LREE enrichments and negative HFSE anomalies. The Sr and Nd isotopic ratios vary from 0.704463 to 0.704921 and from 0.512649 to 0.512774, respectively. CaO/Al2O3 ratios versus MgO, La/Sm ratios versus Rb and Ba and Zr versus Th suggest that that fractional crystallization was a major process during the evolution of magmas. AFC modeling and isotopic data as well as microscopic evidence, clearly indicate that crustal contamination accompanied by the fractional crystallization played an important role in petrogenesis of the trachyandesites. Also, geochemical and isotopic compositions indicate that magma mixing was not essential process in the evolution of Ahar magmas. Alkali basaltswith high 143Nd/144Nd ratio, low 87Sr/86Sr ratio and high MgO, Ni and Cr contents indicate that they crystallized from relatively primitive magmas. REE modelling and Trace element ratios indicate that the alkali baslats were derived by small degrees (1-3%) of partial melting from the spinel lherzolite.

The Dehshir fault system (DFS) including six fault segments forms the western border of NS-striking active dextral strike-slip fault cutting the Sanandaj-Sirjan, Uromieh-Dokhtar magmatic arc, and Central Iran. This active fault system right-laterally offset Eocene volcanic rocks and Quaternary alluvial fans. Geomorphic evidence implies the activity of the DFS in the Late Quaternary, and paleoseismic investigations revealed seismic movements along the Marvast fault segment during the Late Pleistocene and Holocene timescales. In order to unravel the seismic history of the DFS over the intermediate geologic (103 105- years) time scale, and based on the morphotectonics and sedimentarystratigraphic properties, three paleoseismic sites have been selected along the 35-km-long stretch of the Marvast fault segment. The southern site (Harabarjan) shows steep fault branches of N140±10º strike with sub-horizontal striations in dextral component. Another trench has been excavated at the North Marvast site whitin the Late Pleistocene-Holocene alluvial and colluvial deposits.Optically stimulated luminescence (OSL) analysis of loose, quartz-rich deposits yielded an age of ~72 ka for the oldest exposed sediments. Paleoseismic stduies along the Marvast fault segment provide evidence for the occurrence of several large seismic events associated with surface ruptures along the DFS. The chronology of the paleoearthquakes on the Marvast segment indicates that at least 7 large (≈Mw > 7) earthquakes occurred in the last 43 ka with an average recurrence time of 3650±150 years. The most recent earthquake, event I, occurred ~2200 years ago, which associated with 2-4 m of dextral slip and >40 km surface rupture along the Marvast fault segment. These investigations are compatible with the lack of destruction in the Marvast historical (~1300 years) castle, located <10 km east of the DFS. Seismic pattern of the Marvast fault segment could be classified in three temporal clusters and two deformation spans: 1) with significant seismic activities; and 2) with small seismic activities or aseismic. Assuming such a seismic pattern remains similar until the next seismic cycle, the Marvast fault segment is experiencing the last seismic cluster. Considering the shortest time interval between two successive earthquakes (2000 years) may indicate the immennet threat of another destructive earthquake along the Marvast fault segment.

Geomorphic evidence along the Siah kuh fault (North of Jajarm) shows this fault has been active during Quaternary. Faulted Quaternary deposits, deflected and offset streams and bisected alluvial fans are among such evidence. These together with fault scarps in Neogene and Quaternary strata reveal young left-lateral motions on the Siah kuh fault as a part of the Shahrud fault system. However, there are Paleozoic and Mesozoic Formations juxtaposed with Neogene and Quaternary deposits along the fault. Some of these old units have cropped out in northeastern termination and bends along the fault, while others are observed where there is not a bend. Therefore, thrust faulting must have brought them to the surface. Aeromagnetic maps show that Siah kuh fault coincides with an aeromagnetic lineament. Consequently, the geomorphic features suggest only the youngest slips on the fault. Therefore, the Siah Kuh has been a thrust fault whose kinematics change and initiation of left-lateral motions resulted from changes in stress regimes and a regional reorganization during Quaternary.

Iran is in the middle part of the seismic belt of Alps-Himalayas with dissimilar geological, structural and seismological features. In the present article, zonation maps of the earthquake occurrence rate (Rate) and the largest observed earthquakes (Mmax) have been prepared for all the regions of Iran. The parameter (Rate) shows the number of occurred earthquakes intheyear in the region of Iran. Subsequently, according to the zonations, classification of different regions with different seismic activities will be achievable. The zonation map of earthquake occurrence frequency (Rate) in the present article shows that trend of the main classifiedzonations,according to the calculations, is similar with the geological and structural features of the region. It seems that zonation of Zagros and certain parts of the east of Alborz and Kopedagh with the maximum rate of earthquakes are drastically different with the zonation of centralparts of Iran, Makran and eastern part of Iran with low seismic activities. In addition to zonation maps of the earthquake occurrence rate, zonation of the largest observed earthquakes (Mmax) has been provided in this region as well. According to the map, different regions of the Central part of Iran and Alborz with large seismic activities are different with other regions of Iran. Having compared the two zonation maps in this article, it is possible to classify the seismic activities of different regions. The seismic data and the basis of the article are according to the National and International Seismology catalogue for a period of 1900 to 2008.

A major part of source rocks in the Zagros Fold Belt were deposited during Neocomian time; the lowermost part of the Garau Formation has charged the Early Cretaceous Petroleum System of the Lurestan province. These source rocks are widely distributed in the Lurestan Depression and in the NW part of the Dezful Embayment. The Kabir-Kuh anticline, which is a prominent structure of the Lurestan province, is more than 200 km long, and contains outcrop of the Garau Formation. Natural fracture systems have an important role in increasing of permeability and sometimes porosity of many reservoirs, and are necessary for the primary migration of hydrocarbons from the source rock to the reservoir. We have collected and analyzed field data on fracture set densities and types in Garau Formation and in parts of Sarvak Formation which outcrop in the Kabir kuh anticline of Zagros Belt. According to our analyses we haveidentified 8 fracture sets in 4 fracture systems: 1) a NNE-SSW transverse fracture system (sets A and B), 2) an ESE-WNW longitudinal fracture system (sets C and D), 3) a NE-SW and NNWSSE oblique fracture system (sets E and F), 4) a SE-NW and ENE-WSW oblique fracture system (sets G and H). The transverse fractures and their orthogonal stylolites are Early Cretaceous to pre-late Miocene in age, while longitudinal and oblique fracture systems have formed since Late Miocene. Some transverse fractures show calcite infillings. We suggest that there have been two phases of counterclockwise rotation in orientation of the stress fields that produced these fractures, 1) a counterclockwise rotation of the stress field between development of non-mineralized fractures and open fractures and 2) a counterclockwise rotation of the stress field between development of the oblique fracture system (sets E and F) and the extension fractures (sets A and B). These rotations in the stress field have probably occurred due to rotation of the Arabian plate during its convergence to the Eurasian plate.

The active faults upon which Tehran megacity was developed must be considered in urban planning. Insufficient preciseness and completenessof the previous fault maps and lack of required technical documentation for existing regulations on building construction in fault zones, prompted the Tehran disaster mitigation and management organization (TDMMO) to scrutinize existing fault map and produce more accurate one and in the same time devise new regulations. To this end, the Alquist-Priolo (AP) Earthquake Fault Zoning Act and sets of Fault Evaluation Reports and Fault Investigation Reports of California were reviewed and necessary conclusions regarding eventual adoption of similar measures for Tehran were drawn.

Tertiary volcanism in east and northeast of Nehbandan, eastern Iran, includes mostly basic-intermediate associations. They are characterized by sodic (1 Keywords: Calcalkaline basalt, Low, K tholeiite, Subduction zone magmatism, Sistan suture zone