GEOSCIENCES
Year:2019 | Volume:28 | Issue:112 |Papers Count:33

In many industrial and construction projects in the country, the lack of attention paid by employers to geological considerations has led to many dangers and challenges. In massive mechanized tunneling projects, there is a need for extensive geological studies. These studies require sufficient knowledge of various fields of geology (engineering geology, hydrogeology, tectonics, sedimentology, petrology, stratigraphygeophysics, geomorphology, etc. ). In this research, the view of graduates of engineering geology (employed in the industrial sector), about educational and industrial experiences has been studied. This research is a descriptive survey. The research population consisted of all active engineers of geology in the country. By using simple random sampling, 50 people were selected. Data were collected by a researcher-made questionnaire, and data were interpreted using descriptive statistics. The results of the survey show that in many specialized courses and in undergraduate practical units, technological applications of topics in related industries (tunneling, roads, mines, dam, oil exploration, etc. ) have not been addressed. From the perspective of the population of the statistical community, the current curriculum needs to be reviewed and new lessons need to be developed. The results show that a small part of the students’ practical units in applied spaces are performed. According to people, in the field of postgraduate studies, a significant proportion of theses have a theoretical and fundamental aspect. On the other hand, there is no research collaboration in interdisciplinary research between geological colleges and engineering faculties (in the fields related to the mechanized drilling industry, such as electronics, mechanics, etc. ). Hence, in many student studies, there is no targeted approach to the country’ s industries (including the tunnel industry). The results show that, in the current situation, the revision of educational topics and the wider activity of geological associations (for the purposeful communication with the industries of the country) can enhance the potential of geology graduates in industrial jobs. Therefore, in this paper, with a brief overview of the conditions of geological groups and the country’ s mechanized drilling industry, suggestions are presented to solve the challenges.

The North Narbaghi deposit is located 26 km northeast of the city of Saveh in the central part of Urumieh-Dokhtar magmatic arc of Iran. In this area, the Oligo-Miocene intrusions cut the Eocene volcano-sedimentary rocks intruding into the surrounding rocks causing extensive alteration zones such as phyllic, argillic, propylitic and tourmalinization. The intrusive rocks include diorite, monzodiorite, megadiorite with calc-alkaline nature which formed as a result of subduction of the Neo-Tethyan oceanic crust beneath the Central Iranian block. The epithermal Ag-Cu mineralization at North Narbaghi, with vein-veinlet and breccia geometries is mainly hosted in andesite, lithic tuff, diorite and monzodiorite. At the North Narbaghi deposit, ore minerals can be divided into four groups: sulfides (chalcopyrite, pyrite, sphalerite, bornite), sulfosalts (tetrahedrite, tennantite), carbonates (azurite, malachite) and oxides (hematite, goethite). The alteration shows a relative concentration pattern at the North Narbaghi deposit; the argillic, sericitic and calcite alteration types are in close connection with the Ag-Cu mineralization and the propylitic and tourmalinization alteration types occur at the margin of mineralization. The main characteristics of mineralization such as geodynamic environment, host rocks, mineralogy, metal content, geometry, alteration and comparing these features with the characteristics of epithermal deposits, show that the North Narbaghi deposit can be classified as a typical intermediate-sulfidation (IS) epithermal mineralization.

KoheSiah volcanic complex is in north east of Qorveh in the Kurdistan provinceand in Sanandaj-Sirjan zone. The age of the studied region rocks are related to the quaternary time. Set volcanic cone with a crater that has been identified as unspecified and are an average height of 2157 meters above sea level. The composition of volcanic rocks varies from basaltic composition, Basalitic andesites, andesite and, trachyandesite. On the basis of mineral chemistry the amphiboles are classified as calcic (magnesio-hornblende). Plagioclases vary from andesine-oligoclase to labradorite. Al-barometer accounts that the pressure of amphibole crystallization is 3. 2 to 6. 65 Kbar and Altotal versus Fetotal/(Mg+Fetotal) accounts the pressure between 4. 5 to 7 Kbar. Hornblende-plagioclase thermometer shows 464 to 473 ° C for equilibrium of these two minerals andbiotite thermometer shows 500 to 650 ° C for biotite in andesites.

The Asmari Formation is the main reservoir rock for the Aghajari oil field. It is composed of about 400-meter limestone, dolostone and interlayers of sandstones. Study of 1200 meters drilling cores, 2800 microscopic thin sections, 12 SEM analyses along with 125 routine core tests in 5 cored wells indicate that the Asmari Formation was effected by various diagenetic processes such as micritization, compaction, cementation, fracturing, dissolution and dolomitization. Some of these processes (e. g. dissolution, dolomitization and fracturing) have constructive effects on the reservoir quality and created wide variety of porosity types including vuggy, intercrystaline and channel in upper parts of the Asmari Formation. Destructive diagenetic processes (micritization, compaction and cementation) have destroyed pore spaces and make the lower parts of the Asmari (specially zone 5) to a non-reservoir unit. Porosity-permeability plots on the Lucia’ s diagram show sandstones and carbonates rocks with interparticle porosities have good reservoir qualities and always plot on upper parts of classes 1-3. Samples with fracture porosity mainly plot on upper part of class 1. This shows fractures has no considerable role in promoting the porosity, but they strongly increase permeability. Dolostones and the rocks with vuggy porosity have plotted on classes 2 and 3 (high porosity, relatively high permeability). Paragenetic secession of the Asmari Formation shows the diagenetic processes occurred syn-sedimentary on sea floor, after sedimentation during the low-deep burry and uplift. The results of this study can be useful in detection of reservoir zones, increasing of hydrocarbon production and enhanced recovery of this oilfield.

The Baharieh copper deposit with 1 Mt Cu ore is located in 30 km of NE Kashmar city. The copper mineralization with 200m length and eastwest trending which occurs in andesitic-to rhyolitic-tuff (middle Eocene). Volcanic to subvolcanic rocks are composed of andesite, dacite and rhyolite and according to geochemistry of immobile trace elements (e. g., La, Yb and Zr); the igneous rocks straddle within active continent margin arcs. The vein minerals consist of main sulfide minerals such as chalcopyrite and pyrite, which accompanied with bornite, covelline, and chalcocite. Silicic, calcitic, chloritic and argillic are the main alteration assemblage with mineralization. Two types of fluid inclusions including of liquid-rich (LV-type) and vapor-rich (VL-type) are distinguished in quartz-ore stage of the Baharieh deposit. Homogenization temperature and salinity are recorded varies from 187 to 356 ° C and 0. 99 to 18. 7 wt% NaCl eq. Some characteristic as vein, breccia and vuggy textures, volcanic host rocks, low temperature alteration, simple ore minerals and high chalcopyrite content, temperature and salinity of fluids and the other evidences shows Baharieh copper deposit is similar to in Cu (Ag) manto-type (volcanic red bed) deposit at Chile.

Forumad area is located in NW of Sabzevar, in NE of central Iran structural zone and in western part of Sabzevar ophiolite suite. The mantle section of Forumad ophiolite consists mainly of harzburgites, dunites, pyroxenitic dikes and choromititic lenses that contain brown to black Cr-spinels. The content of Cr2O3 and Al2O3 of Cr-spinels in harzburgites are between 32. 6-53. 1 and 15. 6-34. 8 wt%, respectively, and their Cr# ([100 × Cr/(Cr + Al]) atomic ratio]) is between 39-69%. Relationship between Cr# of Cr-spinels and Fo of coexisting olivine (Fo=91-92%), and orthopyroxene and low contents of TiO2 (<0. 06 wt%) indicating that harzburgites fall whitin the olivine-spinel mantle array (OSMA), and plot in abyssal and forearc peridotites fields and are residual of moderate degrees of partial melting (about 15 to 26%) from moderately depleted mantle. But, the content of Cr# in Cr-spinels of dunites, chromitites and pyroxenites are high (between 81-. 85%), and associated to boninitic melts and indicate that formed by high degrees of partial melting. Consequently, minerals chemistry of Cr-spinel, clinopyroxene, orthopyroxene and olivine of mantle section from Forumad ophiolite indicate that genesis of this ophiolite have been involved in a suprasubduction zone, and developed as a result of northward subduction of the sea/ocean of the Neo-Tethys in response to the convergence between the Central-east Iranian microcontinent and Alborz (Turan) plates.

In Takht-e-Soleyman region, travertine deposits are widespread in the footwall of the Chahartagh fault. Three factors played roles in forming travertine in this area: magmatism and high geothermal gradient, existence of carbonates between thermal source at depth and travertine springs on the ground, so that the hydrothermal solution can provide the necessary ingredients for the formation of travertine. The third factor is extensional faults and fractures to conduct water containing dissolved calcium carbonate up to the surface. Young magmatism in the region plays an important role in increasing the region’ s geothermal gradient. Absence of travertine on the top of the metamorphic basement, even in the footwall of the Chahartagh fault, highlights the essential role of second factor in formation of the travertine. Sources of travertines in this area are carbonates from the Jangoutaran and Qom formations, with the more emphasis on the latter based on our data. Right-lateral kinematics on the Chahartagh fault led to an NNW extension in the southeastern termination of the fault, paving the way for emergence of the travertine. However, there is evidence for a regional NE extension responsible for NW-SE normal faults in the area.

Several distinct morphologies of tourmaline have been identified in Mashhad biotite-muscovite granite: nodule, pegmatite, aplite, quartztourmaline veins, tourmaline-rich veins and radial tourmalines. The δ 18O and δ D values in solar tourmaline (12. 4 and-69 ‰ ), nodule tourmaline (11. 8 and-63), quartz-tourmaline vein (11. 7 and-57), pegmatite tourmaline (11. 62-11. 67 and-59 to-73), aplite tourmaline (11. 39 and-57), tourmaline-rich vein (11. 82 and-62) and mica schist tourmaline (11. 06 and-77) with low changes are similar together. These values show same origin for tourmalines fluid source in biotite-muscovite granite. The difference in δ 18O values between quartz and tourmaline (Δ qtz-tur) are positive (between+2. 0 and+2. 2‰ ), and this show quartz and tourmaline are in equilibrium. The δ 18O thermometry of tourmaline-quartz minerals show a range between 492° C and 579 ° C for tourmaline crystallization. The calculated δ 18O, and δ D values of the initial fluid in equilibrium with tourmaline suggest a magmatic and primitive magmatic water of peraluminous granite source. All tourmalines show similar δ 11B values (with a narrow range between − 7. 4 and − 10. 8‰ ). This indicates a same boron source for them that resulting during highly evolved magmatic differentiation. Based on the 11B values of tourmalines in Mashhad fall within the range reported for granite-related tourmaline and similar to the S-type source granites that derived by Continental crust. The δ 11B values of tourmalines show the δ 11B values of the magma of the biotite-muscovite granite.

The attenuation of seismic waves, as a basic physical parameter is one of the important properties of the earth’ s structure. Therefore, for a realistic seismic hazard analysis and the simulation of strong ground motions and for studying the regional earth structure, the estimation of the seismic attenuation has a fundamental and inevitable role. The attenuation of the seismic waves is defined by the inverse of quality factor (Q-1) while quality factor (Q) is the wave transmission quality of the medium. In this study, the quality factor was estimated by using two single-back-scattering and single-isotropic-scattering methods. The larger values indicate more homogeneity in the shallow layers of the earth, and therefore, these results can be used in hazard analysis assessment. For this purpose, the seismograms of earthquakes recorded at the stations of the Iranian Seismological Center (IRSC) and the International Institute of Earthquake Engineering and Seismology (IIEES) at the longitude of 48 to 50 and latitude of 38 to 40 degrees have been used in the present study. In this work, the high-quality seismograms with signal-to-noise ratios (SNR) of equal or greater than 3 and epicentral distances less than 200 km were used. The variation of coda wave attenuation was investigated in both lateral and depth, and the results were compared with the obtained values for other regions of Iran and the world. To investigate the lateral variations, after applying the band-pass filter on waveforms in 10 frequency bands, the quality factor was estimated. Finally, the mean values of the quality factor and frequency dependence factor in the region, using data with epicentral distances less than 200 km by using two Single-Back-Scattering and Single-Isotropic-Scattering methods obtained Qc=149 ± 9f0. 66 ± 0. 03 and Qc=152 ± 12f0. 66 ± 0. 03, respectively. The comparison of these results with the values have been obtained for Central Iran (Qc=94f0. 97), Alborz (Qc=79f1. 07) and Southeast Zagros (Qc=72f1. 19) indicate that the study area is more homogeneity in the shallow depth layers and it has less seismicity than Central Iran, Alborz, and Zagros. Also, to investigate the depth variation of attenuation in this study, the coda quality factor Qc was estimated for 11 coda window lengths, which are taken from 10 to 60 s with an increment of 5 s. In the lower window lengths, the low Q0 values represent high heterogeneity in the shallow depths layers of the earth.

The purpose of this research is to identify quaternary units and determine the sediment boundaries around Yazd city in Central Iran. The origin of Quaternary sediments is mainly related to erosion of the Triassic, Cretaceous, and Palaeozoic units. Based on the results of sedimentation, six types of facies were identified as Mud, silt, sandy silt, silty sand, mud sands and sandy mud. The XRD results of the samples show that these specimens consist mainly of quartz, calcite, dolomite, feldspar, coperite and clay minerals. In the fossil studies of two important species of ostracodes called Ilyocypris sp. Which refers to sweet waters and Candona. sp, which relate to various saline waters. Due to the diversity of facies and fossils, approximately the lake in the study area was developed in late Quaternary. Facies characteristics, the type of minerals and index fossils indicate that the sedimentation of these facies in a sedimentary lake environment that was first identified in the study area.

The North Shahrekord Metamorphic Complex (NSMC) in the center of Sanandaj-Sirjan Zone includes metagranite bodies, which has been intruded in some metamorphic rocks, especially schists. The NSMC metagranites display metamorphic and distinctive ductile deformation characteristics. These rocks are composed of quartz, alkali feldspar, plagioclase, biotite, amphibole, epidote, garnet, zircon, allanite, titanite, apatite and magnetite. Ages of the NSMC metagranites by zircon U– Pb shows the age of 523. 92 [+ 5. 03 – 5. 73] Ma, and the whole rock Rb– Sr isotopes represents the age of 504 ± 47. The ages of NSMC metagranites (middle Cambrian) are younger than the Late Neoproterozoic-Lower Cambrian granitoids of the Sanandaj-Sirjan Zone, the NSMC metagranites are formed in the post-collisional setting, while the older granitoids are mostly related to volcanic arc. According to the morphology and shape of zircon crystals in NSMC metagranites, most of zircons are placed on S19 and S15 areas in morphology classification of zircon crystals, therefore, the granite magma of the area has hybrid (crust and mantle) origin. The crystallization temperature of metagranites, according to zircon morphology studies, is 750 to 850 ° C, based on Zircon saturation calculation method, is 753. 2 to 828. 5 ° C, and based on the graphical method (results of total rock chemical analyses), is 760 to 830 ° C.

Accumulation of potentially toxic elements in agriculture soil is one of the main serious environmental concerns in the greenhouse cultivation. The environmental investigation of potentially toxic elements (V, Ag, Se, Ni, Pb, As, Cr, Co, Cd, Cu, Fe, Mo, Mn, Sn, Sb, Bi and Zn) in the greenhouse cultivated soils of the Bagher-Abad area, Jiroft is the main objective of this study. After preliminary field investigations, 20 soil samples were collected by mean of composite method. Collected samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) method at the Labwest laboratory, Perth, Australia. The results were discussed using statistical methods and environmental indices with respect to the natural background and worldwide concentrations of target elements. The data showed that only Zn, Cd, Mo, As and in some cases Sb have medium enrichment in the investigated soils. For some of the selected soils the bioavailability or solubility of target elements was determined using 0. 005M DTPA leaching solution. Among the investigated elements Cd and Zn showed the maximum bioavailable fraction corresponding to the medium to high risk assessment codes. Antimony is the only trace element that showed poor enrichment (39. 3 μ g/L) in the irrigation water used for the target greenhouse soils.

The Khankeshi stratabound copper deposit is located in Markazi province, 80 Km SW of Tehran. The area is covered by a sequence of E-W trending lava flows and pyroclastic of Late Eocene age. The volcanic rocks can be classified as trachyandesite and andesite. The rocks contain a high fraction of potassium calc-alkaline and their geochemical characteristics attribute them to back arc basin and extentional processes. The oldest rocks of the study area are Elta unit, composed of green andesitic tuff located in south eastern of the khankeshi. This part indicates a basin with volcanic activities and exhalites, and green tuff with thin lamination combined with microcrystalline carbonates. On the other hand, presence of carbonate of micrite with framboidal pyrite in this part indicated reducing environment and Exhalites activity by source of sulfur in manto type mineralization in the khankeshi. The host rock is Elt type latite andesite with mega porphyritic texture and involved major ore chalcopyrite, bornite with pyrite and minor chalcocite, covellite, hematite, Goethite and malachite with dolomite and dolosparite veins. Framboidal pyrite is replaced with forms of fine and circle chalcopyrite and bornite in primary micritic background and subhedral crystals into dolosparite veins of crystallized micrititic carbonate micrite in forms of epigenetic that produce the supergene secondary production. This unit with pyroclastics and tuff breccias(Elta unit), indicated volcanic cycle that mineralization of copper, in forms of stratabound, has taken place in it. Local alteration associated with copper mineralization includes weak chloritization, oxidation with local argillic, serecitic and zeolitic. Mineralization is stratabound and copper mineralization occurs as disseminated, vein-veinlet, open space fillings and replacements. Based on fluid inclusion studies on coexisting calcite, Homogenization temperatures are between 129. 4 to 227. 1(with an average of 175° C). Salinity varies between 1. 91 to 13. 40(average 12) wt٪ NaCl eq. The depth of fluid inclusion trapping is estimated to be less than 200 meters and ore formation has occurred at pressure values less than 74 bars. Geological, ore mineralogy, ore texture, structures and fluid inclusions characteristics in the khankeshi deposit are similar to those reported from Manto type copper deposits.

Modern data storage and communication technology has created an opportunity to rethink the manner in which geosciences information is archived and presented. The Geosciences Database must provide a mechanism to allow rapid access to up-to-date geosciences data in a form tailored to the needs of the user requesting the data. The data model underlying this database must be flexible enough to encompass a wide range of earth science information, storing it in such a fashion that advances in Earth science do not obsolete the database. One of the major goals of a geosciences data model is to simplify the process of generating derivative maps tailored to specific needs e. g. tectonic analysis, hazard assessment, mineral exploration. Such data may need to be based on information from many sources. Presently, in the derivative maps are usually compiled by manually extracting (i. e. tracing on paper) information from a number of printed maps, probably generated by different people with different motivations at different scales, and graphically combining the information (i. e. redrafting) into a single, derivative map. The goal of the geosciences conceptual data model is to provide basic information from a variety of sources in a consistent, flexible, and searchable structure. In this research, regarding the importance of the maps in data interpretation of geosciences, geological maps is the base for the conceptual data models. Using this base, required domains is defined. The model outlined here provides a conceptual framework that could accommodate newly acquired field data or data mined from previously published sources into a common framework.

The Alborz Mountain range is formed by collision between the Central Iran and Eurasia plates, since Late Triassic. Facieses studies on the Alborz and Central Iran indicate sedimentation in shelf and epicontinental shelf in passive margin of Gondwana during Paleozoic Era. This study represents direction and paleostress analysis of the Central Alborz based on geometry and kinematics of faults; i. e. strike, dip, slicken line orientation and movement directions for Carboniferous and Permian Periods. Since many tectonic events occur after the Paleozoic Era in the Alborz Mountain range so just growth faults, active during sedimentation, which were not reactivated by later events were used for paleostress analysis. In total 15 stations, including 148 fault data are measured along the Tehran-Chalus road from Carboniferous and Permian outcrops. The data were rotated to the first position based on fold axes, when the layers were horizontal. FSA software (Fault Slip Analysis) was used to calculate orientations of principal stress directions. Primary results indicate a proximately North-South extension in Carboniferous and Permian Periods. Iran and adjacent area, rotated along vertical axis during its movements from Gondwana, in South, to Eurasia, in north, that based on the plate rotation the extension direction for Permian and Carboniferous Periods are NE-SW and ENE-WSW, respectively.

Most of the country’ s geographically area is located in dry and semi-dry zone with low rainfall. The growing population, the limitation of water resources and the prevalence of groundwater resources in most parts of the country requirement to accurate prediction of the amount of these resources due to the importance of these resources in optimal planning and management. In this research, in order to estimate the fluctuations of groundwater level in the Baruq aquifer, the artificial intelligence models including fuzzy, support vector machine and neural network models were used by the data of depth from 7 piezometers with long-term data of 14 years, as well as changes in temperature and precipitation in this period. Despite the inherent abilities of each models in predicting groundwater level, the heterogeneity of the study area prevented the high efficiency of these models. Therefore, SOM-AI modeling combined the self-organized maps (SOM) classification method and each model that is increased the efficiency of each composite model in different parts of the aquifer by dividing the study area into homogeneous regions. The results showed that the proposed method can be an effective method in the modeling of heterogeneous and even multi-layered aquifers.

Jalambadan area is located northwestern Sabzevar, Khorasan Razavi province, and southwestern Quchan-Sabzevar magmatic belt. Geology of the area includes of andesitic-trachyanesitic volcanic rocks, which is intruded by monzodioritic to dioritic subvolcanic intrusive rocks. The texture of igneous rocks is porphyry and the main minerals are plagioclase, alkali fldespar, pyroxene, hornblende, and magnetite. Age of intrusive rocks determined 44. 7 to 45. 2 Ma (Middle Eocene-Lutetian), using zircon U-Pb method. Geochemically, igneous rocks of the area are calc-alkaline and were formed at subduction zone. Relativelly, enrichment in LREE relative to HREE and enrichment of K, Rb, Cs, and Sr relative to Ti and Nb elements are observed in all of samples. Eu anomaly and Sr/Y ratios can be attributed to the presence of residual plagioclase and a few garnet in a source. (87Sr/86Sr)i (0. 703708 to 0. 704444), (143Nd/144Nd)i (0. 512858 to 0. . 512933), and ε Nd I (5. 42 to 6. 88) values of intrusions and geochemical signatures of volcanic rocks indicate magma is drived from partial melting (7-5% for intrusions and 15-25% for volcanic rocks) of spinel lherzolite mantle wedge above subducted slab, which is assimilated slightly with upper continental crust very little.

Semnan plain is located in the northern margin of Iran’ s central desert and has a dry to semi-arid climate. In recent decades, rapid population growth, increasing Industrial areas and water demand has led to excessive extraction of groundwater resources and as a result, the depth of access to the surface of the water will intensify. This reason has made the Semnan plain one of the most important areas of the country in view of water resources scarcity and its consequences. In this research, to estimate the ground subsidencein the period of 26/03/2008 to 23/8/2003 by using Satellite Image Interferometry (InSAR) method, the maximum subsidence of 133 mm in the city of Semnan and its surroundings Has been confirmed. In order to identify the factors affecting the subsidence of a part of Semnan plain, underground water depth fluctuations along with a hydrograph diagram of the results of 15 observational wells were investigated, indicating a continuous decline in water level during the years 2003-2009, so that the minimum Growth rate of groundwater depth of study area is 22 cm / year. What results from adaptation of subsidence areas and water table water level drop curves in this study is that exploitation of groundwater resources more than aquifer nutrition increased effective stress and consequently high consolidation of sediments which caused this factor Semnan plain due to geotechnical properties of the aquifer are susceptible to subsidence. In other words, subsidence zones over, or near, the groundwater level decrease areas. Therefore, water resources management should be given more and more attention by Politicans, who makes policy, in order to keep up with Sustainable development of agriculture and industry to prevent the ongoing process of land subsidence.

Accuracy incretion and search space reduction are the main purposes in production of mineral prospectivity maps. Choice of the suitable method for information integration in the geographical information system which has the most consistent with the nature of the used data, is the first step in achieving to this goal. Due to the fact that exploratory data are not independent and most of them has feedback among criteria and sub-criteria and according to the one-way dependence condition of the evaluated data in the Analytic Hierarchy Process (AHP) approach, an Analytic Network Process (ANP) approach is assigned. Exploratory data related to the Bavanat Region in Fars province are used, in case of providing the mineral prospectivity model for besshi type massive sulfide deposits. We tried to optimize two factors of the search area and accuracy to highest accuracy of the results and the least amount of search area. AHP as well as ANP approach, is knowledge-based approaches. The results of the research in AHP and ANP approaches in studied area indicate that, the ANP results is more reliable and has less suggested search area than AHP approach. Based on the results, suggested areas of ANP are 17% less than AHP (1138. 4 Km2 in AHP has decreased to 952. 6 Km2 in ANP), while, the accuracy of the results has increased more than 6%. The Receiver operating characteristic (ROC) curve index (area under the curve) shows that AHP approach ROC is 0. 7609, which was improved and optimized by the ANP approach to 0. 8275.

The Oligocene-Miocene Daredesk pluton, located in southeastern part of the Urumieh– Dokhtar magmatic assemblage, is outcropped in the Eocene volcanic rocks in northeastern Jiroft. The pluton comprises mainly of diorite, quartz diorite, quartz monzodiotrite and granodiorite with metaluminous and calcalkaline affinity. They have petrographic and geochemical characteristics of I-type granitoids. Condrite and MORB normalized multi element spider diagrams for the Daredesk granitoid rocks show marked negative Ti, Nb and Ta anomaly and an enrichment of LILE (e. g Rb, Cs snd Ba). This feature together with other geochemical specifications, tectonic discrimination diagrams and geological position of the Daredesk pluton indicate its formation in an active continental margin setting. Also, chondrite-normalized rare earth element patterns of the Daredesk intrusive rocks show a gentle slope with (La/Yb)n= 3-6/4, indicate nonexistence of garnet as a residual phase in the source. All these features together with the occurrences of mafic microgranular enclaves, MgO and Cr contents, Th/Rb, Nb/Yb, Rb/Sr and Ba/Rb ratios clearly show that the Daredesk granitoid rockes formed by interaction between a primary mafic magma, produced by partial melting of metasomatized lithospheric mantle, with continental crust.

In the current study, using microtremor measurements at 15 stations of strong ground motion network in North-western Iran, dominant frequency is determined and sites are categorized. After correction of raw data, horizontal to vertical spectral ratio is calculated and the frequency corresponding to the greatest amplitude is acknowledged as the dominant frequency. Also at 11 stations with good quality of recorded microtremors, horizontal to vertical ratio of earthquake motion is calculated. Agreement between these two spectral ratios is quite satisfactory. Maximum and minimum observed dominant frequencies are 1. 72 and 7. 34 respectively. Correspondingly, using past studies, shear wave at the top 30 m is estimated and based on different seismic codes, sites are categorized. If the categorization based on predominant frequency is compared with categorization based on reported by building and housing research center, dramatic differences will be observed. These differences could be attributed to uncertainties in reported Vs30 as well as estimated dominant frequencies.

Qarachilar Cu-Mo-Au mineralization is located within the Qaradagh batholite in the Arasbaran metalogenic zone. This area is a part of southern margin of Lesser Caucasus. Qaradagh batholite at the Qarachilar mineralization area composed of granodiorite-quartz monzodiorite (as host rock of mineralization), diorite, quartz monzonitic stocks, apophyses of porphyritic granite and acidic to intermediate dykes. All of the mentioned intrusions have calc-alkaline to high-K calc-alkaline nature and classified as metaluminous I-type granites. The porphyritic granite apophyses and dykes, and quartz monzonitic stocks have adakitic nature and can be classified as high silica adakites. Chondrite normalized REE patterns in granodiorites-quartz monzodiorites indicate enrichment in LREE and flat trend in MREE and HREE, while porphyritic granites show steep pattern with enrichment in LREE and depletion in HREE. Based on field investigation, geological, petrological, geochemical and tectonomagmatic discrimination diagrams, it can be conclude that granodiorite-quartz monzodiorite phase was formed in active continental margin as a result of Neo-Tethyan ocean subduction beneath the Eurasia. The quartz monzonite stocks and porphyritic granites were formed in a post collisional setting from metasomatized lithospheric mantle wedge.

Estuaries are considered as the most important source of different pollutants, especially heavy metals toward the lakes, seas and oceans. The research aim is to investigate the heavy metals behavior in the estuarine zone, where a Sea and a River meet each other. In this research, samples of Suspended Particulate Materials (SPMs) and water of Sefidrud River and Caspian Sea were sampled to simulate the estuary physically. Sequential extraction procedure was performed to determined heavy metals concentration in different species. Adsorption-Desorption experiment revealed that during estuarine mixing while manganese and copper are desorbed from SPMs by 531 and 5/4 ppm respectively, zinc and lead are adsorbed by 19 and 8 ppm respectively. Nickel shows a conservative behavior in the Adsorption-Desorption experiment. Risk Assessment Code (RAC) was applied in this study to determine potential of heavy metals release from SPMs as they enter estuarine mixing zone. Results show Mn is likely to release more from SPMs due to environmental changes.

Taft area is located in the central part of Urmia-Dokhtar Magmatic Arc (UDMA), adjacent to Western block of Dehshir Major Fault. More than 100 copper occurrences were identified in UDMA. It seemed that these Cu occurrences are related to structures, especially major and main faults. Therefore, the Taft area is selected for investigation on relationship between Cu mineralization and Tectonics (and structures). In this research, the main structures are extracted and analyzed by using Remote sensing techniques, GIS environment and Field investigations. The results show that a Structural Rhombohedral shape created by activating of two order faults with N150-170 and N110-120 trend. In follow, the third-stage of faulting with N60-70 trend cut and offset the all of other formed structures and enumerate as youngest order of faulting in this area. This stage of faulting was taken placed during initiation of collision between Arabian plate and Iranian Micro plates in Oligocene-Miocene episode. Because, this fault zone was formed perpendicular to convergent zone, it has tension component and prepared a suitable environment for I-type Granitoid bodies’ injection. This phenomenon has main role in forming of Porphyry-Skarn Cu mineralization in length of this fault zone.

The Precambrian Kushk Series in the Bafq and Behabad regions of Central Iran contains a diverse assemblage of latest Ediacaran fossils that showcase a fossil assemblage much more diverse than typically known from the latest Ediacaran systems worldwide. The Kushk Series reaches a thickness of >500 m and consists of carbonate (sandy dolomitic limestone and dolomite) and siliciclastic (shale, sandstone, and siltstone) facies with extensive accumulations of volcanic rhyolite, microdiorite, and tuff, which its argillaceous shales contain an assemblage of abundant Ediacaran fossils including Kuckaraukia multituberculata, Persimedusites chahgazensis, Corumbella werneri, Cloudina sp., Chuaria sp., Kimberella persii, Gibbavasis kushkii, Erniettomorpha, Rangeomorpha and numerous tubular organisms. The discovery of classic terminal-Ediacaran index fossils Cloudina and Corumbella in this assemblage confirms a latest Ediacaran age (Nama-Assemblage ~545-539 Ma) for these deposits. These taxa help expand our understanding of the latest Ediacaran prior to the Ediacaran extinction and the Cambrian explosion of complex animals.

Bagoushi deposit is located at 37 km northwest of Masiri in Fars province. Structurally, the deposit is situated in the Zagros Simply Folded belt and developed in Upper Cretaceous carbonates. From the bottom to top, the deposit is consisted of kaolinitic, brecciated, brown, pisolitic and red bauxite horizons. Boehmite, kaolinite, hematite, pyrophyllite, anatase, calcite and diaspore are the major mineral phases. The main ore textures of the deposit include pisolitic, pisolitic-oolitic and clastic with pelitomorphic and microgranular matrixes. Some textural features such as pelitomorphic matrix, pisolitic and oolitic textures, radial fractures in pisoids, growth of simple cortex around earlier pisoids, pisoids with cortexes lacking radial and circular fractures, are indicative of autochthonous origin; and broken pisoids, allogeneic pisoids and clastic grains reveal the transportation of bauxitic materials; therefore the bauxite materials is authigenic, but in some parts were transported and re-deposited, at least locally. The mass change calculations relative to the immobile element Ti show that elements such as Si, Fe, Mg, K and Na are leached out; Al, Zr, V, Th, Nb, Ba and REEs particularly LREE are concentrated; and Hf, Ta, Co, Rb, Cs, Be and U are relatively immobile during the bauxitisation process. The bauxite ores are characterized by progressive enrichment of the REE compared to parent rock, intense LREE/HREE fractionation, relatively stable negative Eu anomalies, and weak negative Ce anomalies. Geochemical data reveal progressive enrichment of the REE and intense LREE/HREE fractionation toward the lower parts of the bauxite profile. In the studied deposit Ce behaves differently from the other REEs (especially LREE) and show few changes in the Ce anomalies throughout the bauxite horizon. These observations suggest that factors such as fluctuations in soil solution pH, REE ionization potential and function of carbonate host rock as a geochemical barrier had significant role in the distribution and fractionation of trace elements and REEs during bauxitisation in the Bagoushi bauxite deposit. Several lines of evidences such as Eu anomalies, immobile element ratios (Zr/Hf and Nb/Ta), as well as similarity in REE patterns indicate that the underlying marly limestone (Sarvak Formation) could be considered as the source of bauxite horizons and suggest that the source material for the Bagoushi bauxite was provided from a siliciclastic material derived from a continental margin.

The Zagros fold and thrust belt contains a near continuous sedimentary cover which overlies the late Precambrian-Cambrian Hormuz salt formation. The information about this structure is only limited to the study of salt domes. As the density variation of salt is not noticeable with depth, it is expected this structure has a significant role in the decrement of P-wave velocity relative to top layers. The 9 April, 2013 Kaki earthquake (Mw 6. 2) occurred in a part of the Simply Folded Belt of Zagros Mountains where there are two salt domes. So, in case of studying salt structures as low velocity zones at depth, the 1-D inversion was done using 10459 P-arrival times of 978 aftershocks. The results of this study indicates that the two top layers with overall 4 km thickness and average low velocities might be related to incompetent and upper-mobile groups. Sudden seismic velocity increment from 3. 9 km/s to 5. 45 km/s in depth of 4 km can be considered as an indicator for transformation from the upper-mobile to the competent group. Furthermore, an average low velocity zone from 8 km to 12 km is observed that confirms the Hormuz salt series at depth.

Granitoid bodies of west of Zanjan with Precambrian age are located in northwest of central Iranian structural zone. Based on field observations and microscopic studies, these bodies contain tonalite, granodiorite and monzogranite. Tonalite are I-type, calc-alkaline, and peraluminous (206Pb/238U age of 576± 13 Ma) which base on isotopic studies (87Sr/86Sr (i) and ε Nd (i) values equal to 0. 710544,-7. 01), and geochemistry of major and trace elements, can concluded that they were resulted from melting of amphibolitic crust that generated from thickened mafic crust or under plate basalts (with presence of plagioclase in source area) in low pressures and depth in an active continental margin. Monzogranites are S-type, peraluminous and calc-alkaline, which is plotted in collision zone. These rocks were generated from melting of crustal rocks (melt derived from pelitic rocks with high plagioclase). Granodiorite are I-type, calc-alkaline and weakly peraluminous (206Pb/238U age of 548± 27 Ma). They have value of 87Sr/86Sr (i) more than 0. 705, negative value of ε Nd (i), and geochemical data, which is generated from partial melting of lower to middle crust, because of thickening and shortening due to continental-continental collision. With respect of geographical location of granitoid bodies of Mahneshan and age of their units, it seems that these granitoid rocks have formed in an active continental margin during convergence of Central Iran and Alborz-Azarbayjan with Arabian platform during Precambrian.