JOURNAL OF SCIENCES (ISLAMIC AZAD UNIVERSITY)
Year:2009 | Volume:19 | Issue:73 (GEOLOGY ISSUE)|Papers Count:14

Introduction: Bauxite is an important source of many metal ores mainly for Al. The Kicajin bauxite horizon is situated between Elika Formation and Shemshak Formation with erosional contact.Aim: The aim of this research is to identify texture, mineralogy, type of bauxite and its source rocks of Kicajin bauxite horizon.Material and Methods: Texture and mineralogy of the bauxite deposit was thoroughly studied by petrographical examinations of thin sections and by X-ray Diffraction (XRD) method. Bulk chemical analysis on samples was carried out by X-ray Fluorescence (XRF) method.Result: Petrographically, consolidated bauxite show pisolitic, ooidic, and granular texture. Base on major oxides composition (Fe2O3–Al2O3–SiO2), the bauxite samples at Kicajin can be grouped into two mineralogical types, (1) mainly clayey bauxite and, (2) iron-rich bauxite. Diaspore and clay minerals are the principal constituents accompanied by some minor minerals such as Feldspar, Iron-oxides and Anatase.Conclusion: Based upon field evidence, petrographical studies, concentration of elements such as Cr, Ni, Zr and Ga, basic to intermediate igneous rocks which occur in the south of study area are source rock for the bauxite deposit of Kicajin.

Introduction: Analythical hierarchy process (AHP) as one of the manifest technique of multidisciplinary decision and management is suitable decision tool for complex position that criteria are multiple and different.Aim: This paper decide to present the new method for determine development amount of karstic lithologic units. Now for determine this main usually use pumping test, isotopic methods, the spring recession curve,geophysic studies and Modelling that are very high cost or long time.Materials and methods: At this paper with application AHP methd, enclosure determine effective parameters on the karst development, a case study area selected in the southwest the Markazi provice in the Iran and on base pairwise comparisions, priurity extraction and determination of altimate weights of ,alternatives, comporated four blocks  the Emart, shazand, Azna and Besri and for determination of the karst development of different blocks.Results: Emarat block has most development and Besri block has least developed and between the Azna and the shazand blocks, Azna block has more developed.Conclusion: Analythical hierarchy process is suitably method with maximum or minimum information for zonation of karstic area.

Introduction: The biostratigraphy of upper Cretaceous deposits (Santonian – Masstrichtian) regarding to Calcareous Nannofossils and Foraminiferas in South and South east Isfahan have been studied. Nannofossils from south and south east Isfahan had good preservation and high variety. Lithostratigraphic units have different thicknesses that, include marly limestone, shale, and limestone. Fine grained sediments, normally consisting of shale and marly limestone, have the best chance to contain Nannofossils with respect to their content in calcareous Nannofossils.Aim: Santonian-Maastrichtian deposits have identified in south and south east Isfahan and exact age of beds have determined by using Calcareous Nannofossils and Foraminifera.Materials and Methods: Method of "Smear slides" was used in preparation of Calcareous Nannofossils and samples have been studied by using of Microscope (magnifying of 1000 and in same two light of XPL, PPL Microscope). Foraminiferas in these deposits have studied by method of thin sections.Results: In this investigation, twenty-six species and sixteen genera related to the Nannofossils and twenty species and twelve genera related to the Foraminifera have been recognized. On the base of first occurrence of index species and assemblage zone, eight biozone from Sisingh zonation (1978) and three kinds of assemblage zone from Wynd zonation (1965) was suggested in these areas.Conclusion: Time limit of studied species in the south of the Isfahan determines Santonian – Masstrichtian age for these deposits. On the base of exact studies of paleontology, the abundance and variety of different species at this time could be found in warm climate. The presence of species like Micula prinsii, Micula murus which all are to low latitudes and are useful indexes of Upper Maasstrichtain help us conclude that south east Isfahan basin have been located low to middle latitudes.

Introduction: The Gholgholeh area is located in 40 Km southwest of Saghez city and in northwest of Kordestan province. This area is situated in the Saghez 1:100,000 Geological map sheet. This mine is situated in northwest of Iran with upper Cretaceous age. From the viewpoint of general geology, this area is part of the Sanandaj-Sirjan metamorphosed zone.The case of study in the oldest rock-unit outcrops in the north of this area which belongs to Percambrian gneiss. Permian deposit mostly distributed in north, northeast and northwest of this area.Aim: The aim of this study is gold and its element mineralization in Qholqholeh area. This case can start to identification of mineralization in the studied area and their parts.Material and Methods: Course and model mineralization can be investigate to help of desert study, mineralography, geochemical analysis, SEM, thin and polish section and fluid inclusion study.Results: The major types of alteration are composed of silicification, sulfidation, sericitization, chloritization and carbonatization. sercitization and choritization are the most, widespread alterations, whereas, silisification and carbonatizatin are usually limited to the inner zone of altered shear zone and are dependant on the intensity of deformation. SEM and mineralography studies indicate occurrence of sulfide mieralization especially Au sulfides which appeare in two generations. On the base of SEM studies, little Ag and As are observed. There is no gold in calcite. Primary mineral consist of: pyrite, marcazite and calchopyrite, and secondary minerals are pyrite, coveline and realgar. In addition, various pyrites occur as primary and secondary phase mineral. SEM study shows sense of gold in sulfide mineral. On the other hand, fluid inclusion studies shows 350oC temperature in gold formation. Low salinity which shows probably that gold is not carried by chloridric complex in this stage. Daughter mineral in fluid inclusion shown low Cl.Conclusion: Based on present evidence, and comparison with other gold type in the world, gold mineralization type is similar to gold orogenic type. Evidence like Parageneses, elements, gangue and alteration around mineralization area all indicate the presence of monometal gold vein ore deposit of shear zone origin replaced by gold vein in cracks which are depended on this structure. Formation and occurrence gold field are influenced by structural properties and tectonic turnover and kind of hosted rock.

Introduction: Geomorphological observations reveal the presence of active faulting and thrusting in the western part of Lut block, SE. Iran. It appears that the right-lateral shear between the Zagros and Makran mountains has caused the active faulting of this part of central Iran.Aim: Reconnaissance and analysis of active faults, identification of general trend of faults and important joints, which are the tectonic fractures in the proposed area.Material and Methods: The topographic map and ETM data preprocessing methods were used to make a Digital Elevation Model (DEM) of the geological structure, at the study area. The image preprocessing was carried out through filtering‚ homogenization‚ edges clearing‚ topographic reflection.Results: The remote sensing data reveal the distribution of active faulting across large areas of deformation. Concidering the satellite image, the general trend of structures is northwest southeast and follows the Zagros trend.Conclusion: The fault structures in the studied region do appear to be active in the late Quaternary and may be capable of producing destructive earthquakes in the future. The most of existing faults are reverse and some of them show strike-slip movement, which is the indicative of the compressive tectonic regime influencing the whole Iran plateau. The compressional force is as a result of the movement of the Arabian plate toward the Iran plateau and causes the development of the structures with northwest southeast trend.

Introduction: Iran`s coals occur in the Alborz range (north) and Central Iran basins. The Zirab is typical coalfield in the Alborz coal basin. These coals are mainly clarovitrinite to clarodurite type which are used as source of coking coal for metallurgical factories. During the research we used 10 typical samples from Zirab coal mine to estimate fragmentation model of natural particle-size distribution of these coals.Aim: Particle-size distributions of rocks are often used to estimate fragmentation model. Prediction of fragmentation properties from coals is the main aim of this research. In order to calculate the fragmentation model at any stage of the extraction (or sizing) operation, we tried to develop a model that combines both natural fragmentation and degradation through natural crushing. The natural fragmentation is calculated with a modified version of the Kuz-Ram model that improves the prediction of the fine portion of the product.Materials and Methods: Our studies showed that during the fall of coals from 4m height, fragmentation followed average range of 5 percent, per time for particles smaller than a 5mm diameter.Conclusions: It means that if the processes would repeat 20 times, 100 percent of coals would crush to the size of less than 5mm. Also, the results showed that a power-law relation between mass and size of coal particles.

Introduction: The studies area with coordination of 54º 30' E and 35º 18' N is located in the Moalleman area, in the South Western of Torud Quadrangle. In the structurally – sedimentary Zoning, this area lies in depression part. In the north part of worked area crops out the equivalent of Karaj Formation, from Sosanvar Village to south of Gandy Kaolin Mine. Lithologically this formation is composed of shale, marl, micrite, limestone, dolostone, radiolarite, tuffite, zeolite, and bentonite, with the age of Lutecian (Middle Eocene).Aim: This paper has been focused on the types, composition, and environment of bentonite layers of Sosanvar Bentonite Ore.Material and Methods: in the study we used from thin sections, XRD, and XRF.Reasons of use of the analyses were select of appropriate rocks and determination of clay type at bentonites and investigation of its ionic exchangeable.Results: According to studies and investigations the bentonites has been formed from acidic volcanic glass (ryolitic to dacitic), and their magmatic series is calkalkaline, but according to some evidences the magmatic series is alkaline.Conclusion: Changing glasses to bentonite has been occurred under diagenesis conditions, in shallow sea (e.g. Lagoon). The type of clay of this Wyoming – type bentonite is Smectite.

Introduction: The permian sequence of the nortwestern part of Iran (east & west Azarbaijan)deposited in two different basin .In the southern flank, they comprises the Dorud, Ruteh and Nesen formations, but  in the Zal and Illanlu areas , they attributed to Vazhnan, Surmaq, Julfa and Ali Bashi formations respectively.Aim: A precise dating of the carbonate sequences based on the analysis of Fusulinid is also provided. The Dorud and Vazhnan formations correspond to the Assilian to Sakmarian of the lower Permian on the basis of stratigraphical position and it’s similarity with Dorud and Vazhnan formations in Albourz Mountains and central Iran.Materials and Methods: The Ruteh and Surmaq formations correspond to the Kubergandian to Murgabian stages of the Middle Permian and the Nesen Formation represent the entire Dzhulfian stage. The formation of Julfa were attributed to Midian – Early Dzhulfian. and finally, the uppermost beds of Permian of Illanlu and Zal sections are refered to the Late Dzhulfian to Dorashamian stages on the latest proposal of the International  Subcomission on Permian stratigraphy concerning stages boundaries.Results: Refined correlation between the Permian sequences of the studied area and Permian sequences of the Alborz, Central Iran, and Abadeh show that transgression of Permian carbonate platform began during the Kubergandian stage. Conclusion: In this study 25 genera and 35 species of fusulinids belong to different families of Fusulinacea such Schwagerinidae, Schubertellidae, Ozawainellidae, Fusulinidae, Neoschwagerinidae , Verbeekinidae and Stafellidae are recognized and most of them are reported for the first time from Azarbaijan, NW Iran.

Introduction: One of the most important problem in the construction industry is lack of well sand matters in our country. Due to this reason, extensive exploration investigation is necessary to supply parts of society requirement.Aim: The aim of this project is preparing of applied map of sand and Sources to use in industry. Materials and Methods: by using of integrated engineering geology, sedimentology, hydrology and geomorphology data with GIS/RS tecknigues. So all the activities is focused on Mehriz region.Result: According samplings in prospect area and their results, .preparing extensive exploration map will be in future plan and finally one type extensive exploration map based on necessity in sand and gravel industry was provided.Conclusion: One separated and varied extensive exploration map has been provided for civil engineering, geology, sedimentology and hydrogeology experts by sedimentary, GIS and RS data.

Introduction: Haji Abad granitoidic body with an area of 90 km2 is located in 135 Km southwest of Tehran, 7 Km south of Boin Zahra city. This batholith with approximate age 39.2( ±3.2) Ma (2) was emplaced in central of Uromieh – Dokhtar.Aim: In this article we studied petrology, genes and tectenomagmatic aspect of this intrusive body base on the new investigations that were accomplished on these types of rocks.Materials and methods: In beginning of this investigation we did field study and took samples. We used XRF method to analyze major and minor elements and XRD method to mineralogical analyze.Results: Haji Abad pluton consists of Syenogranyte, Monzogranite, Granodiorite and Granophyr (SiO2=63-72wt %). Under study pluton in view of magmatic series is calk-alkaline, medium to high K and in view of alumina saturation index is meta-alumina nature. This granitoids are I-type granite and equivalent with magnetite series. Based on tectonic place these granitoidic rocks are granitoids of continental arc, CAG, and different discrimination tectonic setting diagrams represent that these rocks are volcanic-arc granitoides of continental margins (VAG).Conclusion: this intrusive body was formed in subduction and syntectonic orogenic environment (subduction of oceanic edge of Neotethis to north in early Mesozoic –Cenozoic). Field, petrography and geochemically studies indicate that fractional magmatisim has important role in formation of this pluton.

Introduction: Body and Surfer waves have been produced with earthquake. So that regional seismic Networks have been recorded all local events. Travel time of body waves, between source and stations, to be used for crustal study and Joint Inversion modeling.Aim: Travel times of earthquakes between sources and stations in the north of Iran are used to develop P- and S-wave velocity models across southern Caspian. Errors in travel times are minimized using sources for which locations and origin times are constrained by local data (Sari Network).Material and Methods: The method at this survey base on recorded earthquake in the seismic network, North of Iran. There are the minimum errors of the travel time for local data. The body waves do exist with avalute in the Sari seismic four stations. So that, the travel time curves have been calculated for crustal (Pg, Sg) and Mantel (Pn, Sn) waves. Then we can evaluate the velocity of the wave, with use of modeling of body wave. This study determined Conrad and Moho discontinue depth.Results: Apparent velocities are calculated between 10 and 150 km for P (6.25 km/sec) and S (3.55 km/sec). The value of velocity for P (8.05 km/sec) and S (4.71 km/sec) are calculated in distance ranges of 200-1000 km, which is correspond to depth of Conrad discontinuity, 17-18 km. Moho discontinuity is determined to be at a depth of 36-40 km.Conclusion: We use times from stations in Sari north of Iran and published local summary times as a guide for interpretation at greater ranges. Allowing for known differences in local travel-time residuals between the southern and northern of Iran, the P times are best fit by a model that has a small velocity forward at the base of the crust, and the S times are best fit by a model with a more substantial reduction in velocities. Both P- and S-wave traveltimes are concordant with global averages such as the 1-D earth model AK135. Thus, the velocities inferred beneath the crust are relatively low than those of the crust but not necessarily low relative to global averages.

Introduction: Seismicity is closely related to active Quaternary faults. As a new parameter, FMP is defined to quantify earthquake risk along active faults. The landforms in Tehran quadrangle are mainly controlled by two sets of Quaternary faults, striking northwest-southeast and east-west. The questions are: what are the activity levels of these faults? And will these faults cause destructive earthquakes?Aim: The present study evaluated the movement potential of the major Quaternary faults in Tehran Quadrangle.Materials and Methods: A new method is used to evaluate fault activity by considering the mechanical relationships between fault geometry and regional tectonic stress field. This method has been used to evaluate the fault movement potentials of all the major Quaternary faults in Tehran quadrangle.Result: The fault movement potential of the northwest striking fault set ranges from low to high, suggesting that some fault sets have the sufficient potential for generating destructive earthquakes, except the Telo-e-paeen fault, Kuh-e-Sorkh fault and Bayejan fault. The fault movement potential of the east-west striking fault set like North of Tehran fault is medium, suggesting that this fault set has not the sufficient potential for generating destructive earthquakes.Conclusions: According to this research, the contemporary movements potential along fault zones of various orientations are different under the action of present-day regional north – northeast compressive stress field in studied region. The Mosha fault zone, Niavaran fault, Pishva fault zone, Nava fault, EmamZadeh Davood fault and Pourkan-Vardij fault have high FMP (0.9 or 90%) and the Kuh-e-Sorkh fault zone has very low FMP (0.0 – 0.5).

Introduction: Tarbur Formation (Campanian-Maastrichtian) is acarbonecous lithostratigraphic unit which is distributed in Fars and Lurestan. Really the Tarbur Formation is a rudistic limestone.This formation is sandwiched between Gurpi (Santonian) and Sachun (Paleocene) Formations. Two Tarbur Formation stratigraphic sections in east of Shiraz are chosen which name Kuh-e Gadvan(type section) and Kuh-e Tir.Aim: In this research, biostratigraphic limits and identification of the benthic foraminifers have been studied. Also, study of the evolution of the reefs in these stratigraphic sections are the main objects of this study.Material and Methods: In order to study of introduced objects, field and lab study have been done. 430 samples of two stratigraphic sections have been sampled and prepared thin sections. With using of different sections, index foraminifers have been identified. Also based on the Danhum’s classification (1962) qualitative and quantitive microscopic study have been done.Results: Biostratigraphic limitis of the Tarbur Formation in Kuh-e Gadvan section  is differ from that in Kuh-e Tir section. According to the identified foraminifers, the age of the Tarbur Formation in Kuuh-e Gadvan is Campanian to Maastrichtian and in Kuh-e Tir section is Late Maastrichtian to Early Paleocene. New taxa of foaraminifers are identified which are include: Goupillaudina iranica, G. shirazensis, Gavelinella pertusa. Tarbur Formation of the both studied sections is divided into two lithostratigraphic member which are lower part (Well- bedded rusit limestone) and upper part(massive rudist limestone).Conclusion: Although reef is an ecological unit, deposition of lowermost of reef facies in the studied sections are heterochornous. Lower biostratigraphic limit between Gurpi and Tarbur Formations in Kuh-e Tir section is disconformable. Microfacies studies indicate that stabilization, colonization and diversification stages have been detected in both stratigraphic sections.