JOURNAL OF SCIENCES (ISLAMIC AZAD UNIVERSITY)
Year:2011 | Volume:21 | Issue:81 (GEOLOGY ISSUE)|Papers Count:14

Introduction: 1:50000 map of Saiin Qaleh is located between eastern longitude 49o, 00' to 49o, 15' and northern latitude 36o, 15' to 36o, 30' in 1:250000 geological map of Zanjan. It contains many of metallic and nonmetallic deposits, especially copper, that most of them have hydrothermal type in genesis.Aim: Determination of relation between fractures and joints which are exist in research area with the type of mineralization in Tarom Mountains (Saiin Qaleh).Materials and Methods: The genesis of research area's deposits is studied with putting together the results of field evidences and fractures and joints sampling and their connection with mineralization.Results: At the first, tuffs and breccias and then Andesites and sub plutonic rocks are formed in Tarom region. Khorramdarreh granite has been sufficient role in hydrothermal deposition. Veins have NE – SW trending that it's maximum principal stress azimuth. Silica tuffs are the better host rocks than Andesites for mineralization.Conclusion: Extensional fractures have NE – SW trending that it's maximum principal stress azimuth. These open fractures have considered as main structural controller of copper deposits in Saiin Qaleh area.

Introduction: Many environmental problems are caused by irregular extension of Tehran. The most important problems are petroleum installations in the south of Tehran aquifer, lack of due attention to the environmental standards produced by local petroleum companies, existence of oil plume and its extraction and finally unsuitable condition of industrial and urban wastewater. Aim: To study the pollution of the Rey industrial area, 33 groundwater samples were collected and analyzed.Materials and Method: For investigation of condition of pollution extension and its agents, in addition to collecting previous geochemistry data, 23 wells, 7 qanat and 3 wastewater is sampled in 1385. Data obtained from groundwater sampling compared with world standards and exhibited by hydrocarbons spatial maps (including: 20 Aliphatic, 12 Aromatic and TPH).Results: The Samples are analyzed for determination of 32 aromatic and aliphatic hydrocarbons, TPH. To study the groundwater pollution of Rey industrial area, industrial and urban spatial risk maps are used.Conclusion: The results of laboratory analysis of groundwater samples and the study of the maps of  aforementioned parameters express explicitly that the major part of these resources are not appropriate ones to be used for drinking and farming consumptions. Lack of due care and investigation to the pollution problems of the Rey industrial area will create numerous environmental issues for this area and even for Tehran city in near future. Investigation of source of oily pollutions indicated that these area was strongly influenced by wastewater of industrial and petroleum companies, Firozabad conduit and leaching irrigated lands with its. Attention to condition of area, apparent that coupled method of soil and water remediation is appropriate.

Introduction: Ahar-Jolfa is located in northwestern part of Iran, and it was one of the most active magmatic regions in Iran during Tertiary. Magmatic activities along this axis started in Late Cretaceous, and carried on through Quaternary but not continuously.Aim: To study the magmatic phases that occurred within Ahar-Jolfa axis, and their association with mineralization along this axis.Result: With regards to the outcrops of magmatic rocks along this axis, four separate magmatic phases can be specified.1. Late Cretaceous to Middle Eocene magmatic phase where volcanic rocks and small shallow intrusive bodies are evident and widely seen in the area.2. Late Eocene to Early Oligocene magmatic phase in which only batholiths with composition of gabbro-granite formed, and accompanied with copper mineralization of skarnic and veiny types.3. Miocene-Pliocene magmatic phase where volcanic rocks and small intrusive bodies are seen together and main mineralization within Ahar-Jolfa axis is associated with this magmatic phase.4. Quaternary volcanic phase that produced Quaternary basalts along Ahar-Jolfa axis, and all basalts in Azerbaijan as well.In this paper the data used in petrologic, magmatic and mineralogical analysis includes the results from studying 200 thin sections, 70 XRF analyses and 35 I.C.P. analyses on Au, Cu, Zn, Pb, As, Mo, Sb elements (FA3 method applied for Gold content and IC3E method for the rest of the elements).Conclution: From alteration standpoint, there are three separable alterations observed within Ahar-Jolfa axis with different specifications.1. Regional alteration: it is widely seen along this axis, and its zoning starts from argillic in the bottom, hematitic in the middle, and silisic on the top. This alteration is controlled by lithology, fault zones, and ancient kalderas in the area. In regards to mineralization, this alteration is barren.2. Local alteration: this alteration is seen scarcely in form of fairly small areas along Ahar-Jolfa axis and various zones can be detected including propyllitic, potassic, silisic, algillic, and phyllitic. This local alteration is mostly seen in the areas with shallow intrusive bodies with age of Miocene-Pliocene. This alteration is generally found fruitful. 3. Silisic alteration: it displays a wider age range, and is mostly seen in form of silisic veins with generally gold anomalies, but the gold content and grade is not economically significant.

Introduction: Gurpi formation is one of the most known Formation which has a widespread Zagros, west to southwest of iran. The age of mentioned formation has been reported santoniana to Paleocene. In order to comprehensive stratigraphic and geographical idea about distribution of Gurpi sedments and its age, study of these sediments is unavoidable.Aim: in these research, microbiostigraphical study of the Gurpi formation based on foraminifera in Tang-e-Higoun situated in north of Dehdasht, Kohkilouyeh and Boyerahmad province were considered, and identified and investigated forminiferal species diversity for age determining of the examined sediments.Material and Method: The Gourpi Formation's in these studies section with a thick 253.5 m located at north part of Kuh-e-siah anticline. This formation disconfomably overlies the Sarvak Formation and underlies a purple shale of the Pabdeh Formation. The Gourpi Formation lithologically comprises marl and argillaceous limestone. The study of a total 102 sample, including 16 soft and 8 hard samples, 13 genera and 23 species planktonic foraminifera were identified.Conclusion: On the basis of stratigraphic distribution of index species, the age of the Gurpi Formation in this stratigraphic section is Santonian to Maastrichtian, and biostratigraphically comparable with the planktonic foraminiferal biozonation by Caron. The biozons are as follow: 1- Dicarinella asymetrica Total Range Zone, 2- Globotruncanita elevata Partial Range Zone, 3- Globotruncana ventricosa Interval Range Zone, 4- Radotruncana calcarata Total Range Zone, 5-Globotruncanita stuarti Concurrent range zone 6- Globotruncanella citae Taxon Range Zone.

Introduction: The Barik-Ab mine is located in the northeast of Abhar city (Zanjan province). It is occurred in Alborz-Azarbayjan zone. Breccia tuff and rhyolitic to dacitic lavas are the major rock unites in this area which belongs to Karaj Formation.Aim: Investigating ore mineralization process and it relates to the coexist intrusive rock. Determining the alteration zones and ore deposit genesis.Materials and Methods: After field studies, petrology and ore mineralization were distinguished by the study of 35 thin and polish sections. Different analyses were done for petrography studies and ore grade determining.Results: Mineralization occurred mainly as open space filling and dispersed through the country rock. Mineralization of Pb and Zn, are in the form of galena and sphalerite with paragenesis of chalcopyrite, pyrite, bornite and etc. On the basis of analytical studies, the mean grade of Pb in the samples is 8.02%, Zn=3.4%, Cu=2.09%, Au=918 ppb and Ag=93-197 ppm. In the mineralography studies tetrahedrite is observed within galena.Conclusion: During the extensional phases of Oligocene, the intrusive and volcanic masses in this area were possibly thermal source for transporting of the hydrothermal fluids. Mineralization of this mine is similar to the descriptive model of polymetallic vein deposits.

Introduction: Qom- Zefreh fault system, as the main structure in the area, influences on the geological and tectonical conditions. Study of this active fault has the effects on recognition of tectonical conditions.Aim: In this paper, the young geological features, neotectonic activities and their reprints along Ghom-Zefreh fault system investigated to detect the evidences of qualitative and quantitative rate, type and arrangement of tectonical deformations.Materials and Methods: According to the investigations, this fault system is a dextral fault with a reverse component. Horizontal slip rate in studied part of the Ghom-Zefreh fault system estimated about 2.6 mm/year.Results: According to the morphotectonic indexes (Smf, Vf and SL) and longitudinal profile, lithological changes, and other informations, tectonical activity is calculated for different basins of Baronagh, Jezeh, Ghamsar and Ghohrood. Jezeh has the least tectonical activity. Ghamsar and Ghohrood have the same and the highest activity.Conclusion: Morphotectonic and neotectonic considerations are appropriate tools for evaluating and comparison of tectonical conditions of area qualitativly and quantitatively and the results use practicably.

Introduction: Nowcon area located in the south-east of Iran, in Kerman province and 65Km of south of Rafsanjan in mountain area of pariz district and in 5Km of sar-Cheshmeh cooper mine. Under studied area situated Central Iran zone. The most magmatic events in area are intrusion of multiple plutons that have different compositions abd injected in volcanic rocks. Major parts of intrusions are granodiorite to monzogranite and monzodiorite.Aim: first, Determination of precision mineral chemical composition such as amphibole, biotite, alkali feldspar and plagioclase exist in granodioritic and monzodioritic bodies and then thermobarometry by mentioned minerals that can offer useful information about emplacement depth of plutons.Methods: For the performing of thermobarometry operations, some minerals (as previous mentioned) by analyzed electron microprobe analysis and then by using specific diagrams related to minerals, determined thermobarometry and emplacement depth of plutons.Results: based on obtained results, Plagioclases in granodiorits are labradorite-bytownite and monzodiorite are bytownite and rarely labradorite. Alkali feldspars in granodiorites and monzodiorites on the triangle diagram Or-Ab-An plotted 81-84% or and 57-87% or respectively. Granodiorites and monzodiorites’s Amphiboles in the located in calcic portion and are magnezio-hornblend and hornblend-actonilite respectively. Also biotites in ASPE diagram plotted in biotite section.Conclusion: Existence calcic amphiboles and primary magmatic biotites remark relation these rocks with I-Type granitiods, that generated by orogenic phase. Thermobarometry by using Plagioclase-hornblend show resulted average temperatures by different manners (670-780oC) and average domain pressure on intrusion bodies during emplacement are estimated ~1.2Kbar. Based on, density of average rocks of crust represent that emplacement intrusions performed in ~4.5Km depth of crust.

Introduction: Determination of different zones in porphyry deposits is one of important aims in their exploration because this operation especially determination a supergene zone is important for economical study on these deposits. Traditional methods based on alterations and mineralogical studies are not proper in many cases because these methods are based on petrogaraphical and mineralographical studies, only. Later methods were introduced basis fluid inclusions and isotopes are indirect methods and applied for alterations separation. Fractal methods are applicable in surface geological and geochemical studies for many reasons such as using all data, according to spatial distribution and anomalies geometrical shapes.Aim: In this research, concentration-volume method entitled new fractal method is introduced for separation of supergene, hypogene, oxidant and host rock based on major element grade in porphyry deposits.Materials and Methods: Mathematical base of this method by using of power-law function and partition function for fractal and multifractal modeling, concentration-volume is used for zones separation in Kahang Cu porphyry deposit in Zefreh, Isfahan province. First, Cu distribution in this deposit was evaluated by inverse distance squared method and concentration-volume logarithmic diagram that break points show grade boundaries of different zones and boundary between mineralization and host rock.Results: There is a supergene zone that was not detected by traditional methods.Conclusion: Also, alteration, mineralogical and zonation models were constructed based on geological observation and compared by results from concentration-volume fractal method in Kahang deposit. Separated zones by this fractal method are smaller and near to fact and correlated by geological models. Usage of grade parameter that is most important direct and quality parameter constructed reality results.

Introduction: According to structural changes in western Alborz range from south to north, field geology and tectonosedimentary studies carried on western Alborz, We divide western Alborz range to several tectonostratigraphic zones.Aim: Alborz mountain range is very complicated and interpretation and recognition of geodynamic evolution of Alborz is needed to recognition of geological zones.Materials and Methods: study of deformation styles, faults and their effects on sedimentation, unconformities, Lithological variations in the same periods of geological times, specially from Jurassic period, indicate different geological conditions and are used as fundamental factors for tectonosedimentary zonations of western Alborz mountain range.Results: Alborz Magmatic assemblage (3) is a volcanic arc erupted due to subduction of an oceanic plate under a continental crust (3). Southern and Central Alborz comprise of several rock units of Paleozoic and Mesozoic Era which unconformably underlain by Eocene volcanic rocks. These zones are affected by Early Cimmeride, Late Cimmeride, Austrian, Laramide Pirnean, Attican and Pasadenian orogenic phases. The effects of Late Cimmerian and Austrian orogenic movements in the Median and Southern Alborz are visible in the form of unconformities, but in Northern Alborz which is situated in the northern side of Deylaman and Dorfak faults, there is no evidence of unconformity in rock units of lower Cretaceous time. According to geological investigations, a subsidence phase began in Upper Jurassic and continued to Upper Cretaceous in Northern Alborz zone accompanied by volcanic activity. Northern Alborz comprises of Paleozoic and Mesozoic rocks and the folding rate in this area is less than Central and Southern Alborz zones. After Jurassic period, some variations occur in the rock units of Central and Southern Alborz because of different geologic conditions prevailing in these tectonosedimentary zones. Khazar Coastal Plain or Gorgan- Rasht zone consists of a metamorphic basement and is overlain by thick Quaternary sediments.Conclusion: A correlation between rock units, structural forms, petrotectonic data led to the divisions of Western Alborz Mountain into five tectonosedimentary zones named as: South Alborz Magmatic Assemblage,(3) Southern Alborz, Median Alborz (with Manjil- Shahroud valley and Rostam Abad- Asiabar- Alamkuh subzones), Northern Alborz and Gorgan- Rasht Plain. These zones are separated from each other by several large, deep seated faults.

Introduction: Chah- Juleh area is located in 170 km NE of Yazd city and Central Iran suture zone. The local geological setting consists up Zarigan leucogranite, quartz diorite and diabasic dykes. Zarigan leucogranite is the largest intrusive body by Early Camberian age in the study area.Aim: The main of the research was to confirm albitization, hematitization and U minerlization on the basis of field geology, petrography and geochemistry.Materials and Methods: In the research, we analyzed 63 samples by XRF, 11 samples by XRD in AEO laboratory. Also we used field geology and petrographic data of 23 thin sections.Results: Pseudomorph texture, albite replacing in orthose, heterogenous texture, and chess board texture of plagioclase, high Na2O and low SiO2 and K2O confirm the sodic-feric metasomatism in these rocks.Conclusion: According to petrological and geochemical data, Zarigan leucogranite is I- type granites, sub- alkaline to calc- alkaline, volcanic arc type and ranging from leucogranite, quartz diorite to diabasic dykes. Infiltration of sodic solutions caused albitization and hematitization and U mineralization in the area.

Introduction: The thickness of Bidestan member in Nayband Formation type section has been measured equal to 636.7 meters. It's contact (Norian) with Gelkan member (Lower Norian) has the same slope, and usually is determined by a one meter thick layer of gray Oolitic sandy limestone, with dark gray fresh broken surface.Aim: Nayband Formation usually shows a submarine, and continental facies, in this member which is indicative of Nayband formation sedimentary basin deepening in Norian stage.Material and Method: In systematic studies accomplished on 350 thin sections from Bidestan member.Results: In this paper we obtain 78 Species and Genus of Foraminifera, 27 Species and Genus of Bivalves and 3 Species and Genus of Gastropoda where recognized, and their periodic development in Nayband Formation were exactly determined.Conclusion: This paper considered our findings are compatible with Norian to Upper Norian age for this member.

Introduction: Deh Biraban 1:50000 Sheet situated in Sistan and Baluchestan SE Iran zone has potential for precious elements prospecting basis geological evidences. Nowadays, one of the important issues in economic geology is data analyzing and finding relations between different geological parameters in any area. One of the important issues in economic geology is data analyzing and finding relations between different geological parameters in any area. One of the important parameter is investigated relation between elements distribution and faults and fractures trends in studied area.Aim: Aim is finding relation between faults and elements distribution trends in this sheet.Material and Method: In this paper, faults were found in satellite images in the DehBiraban 1:50000 and digitized in first stage. Next, their strikes were calculated and their rose diagram drawn. Then, data from stream sediments were evaluated and at last distribution trends for Sn, W, Au and Hg were determined by Kriging method.Results: Geostatistical methods are excellent for elements distribution trend evaluation according to Samples spatial distributions and range of sample influence determination that the reasons are caused these methods are more applicated in investigation on elements distribution trends.Conclusion: Results show that variography and distribution of these elements trends was confirming with faults trends in this sheet.

Introduction: This article's objective is to explain slip distribution on faults and understanding further the processes of earthquakes and fault slip, and how they are related. Yet, rare were the studies that tried to compare these slip distributions. Few studies did so, but mainly focused on characterizing the earthquake slip complexity. The overall slip distribution patterns were not considered. Hence, the questions related to the average shape of earthquake slip distributions are still opened.The profiles of maximum and mean slip that extracted from the models in this article allow total slip variations along both fault strike and dip to be studied. The general idea that followed is that analyzing many earthquakes together provides a way of smoothing their individual peculiarities (such as specific slip complexities), so that common, general properties, may emerge.Aim: The present study investigated characterizing average slip distributions on earthquakes beyond their individual heterogeneity.Methods: An auto correlation method was used to define an effective length at which zones of zero (or small) slip is not contributing, even when localized between slip patches. A collection of one-dimensional profiles was prepared, each is given as D(x) (D is displacement or slip; x is position along fault length or width). Hence, all profiles are mathematically comparable and can be analyzed similarly, with a general procedure.Results: While earthquakes are complex features with highly heterogeneous mechanical conditions on their planes (due to pre-stresses, static and dynamic stress loading/unloading by neighboring ruptures, host rock properties, etc…), they share some common, generic properties that appear when a large number of events are examined together: most produce triangular slip profiles (»70% are asymmetric) with well defined, long linear tapers. Triangular slip distributions on earthquake faults seem to be self-similar, suggesting that they attest to a scale-invariant mechanical behavior. Most slip profiles are asymmetric, suggesting different behaviors at the two edges of the major asperity.Conclusion: The maximum and mean slip profiles draw a triangular and asymmetric average curve, while three dominant degrees of asymmetry are revealed. The observation of triangular slip distributions therefore attests to a common, general property of faults, regardless of their scales and kinematics. The area broken during this “first stage” appears as the “major asperity” that shapes the total triangular slip distribution.Most of the moment is released by rupture of this area. This rupture produces dynamic stress overshoot in the surrounding fault plane. This overshoot makes some unfavorably stressed (or in inappropriate energetic conditions) portions of the fault plane in conditions to slip. The linear trends in the final slip profile are taken to be associated with the progressive dissipation of the energy provided by the dynamic rupture of the main asperity.

Introduction: The up to 1298 m thick, mainly turbiditic, siliciclastic Alam Formation consists of conspicuous carbonatic alternations at the lower part, and predominantly of a sequence of marine turbidities with frequent volcanic components at the middle and upper parts, deposited on a forearc side of an active margin in a continental shelf to slope setting.Aim: The study and review of ammonoids collected from the Alam Formation and their paleobiogeographical relationships with other areas.Material and Method: In the present study many ammonoids were collected and systematic studied from different levels of the Alam Formation and their paleobiogeographical distributions and relationships surveyed.Results: Ammonoids collected from different levels of the Alam Formation indicate a Late Scythian to Middle Anisian age for the formation. The recognized ammonoids belong to 35 genera and 31 species, including Epacrochordiceras sp., Procladiscites sp., Pseudosageceras sp., Sturia sp., Acrochordiceras aff. hyatti Meek, Propthyhitoides decipiens, Paragoceras mediterrangeum, Kazahstanites dolnapensis, Isculitoides seyedemamii, Dagnoceras nopscanum, Columbits ventroangusts, Subcolumbites perrinismithi, Prenkites cf. malsorensis, Stacheites undatus, Albanites triadicus, Tirolites cassianus, Metadognoceras amiidi, Eophylites davoudzadehi, Leiophyllites stoecklini, L. aff. pitamaha, Hollandites tozeri, Norites gondola, Nicomedites cf. toulai, Hungarites cf. proponticus,  Stenopapnoceras transiens, Ussurites arthaberi, Semibeyrichites ruttneri, Aghdarbandites ismidicus, Paraceratites aff. binodosus, Parapinacoceras cf. damesi, Ptychites aff. pauli, Gymnites religiouscus, G. palmai, G. asseretoi and Monophyllites kieperti.Conclusion: The mentioned ammonoids belong to a single bio-province at southern margin of Turan continent and have common faunas with the Nazarkardeh Formation in Aghdarband area (NE Iran). The paleobiogeographical relationships of Triassic ammonoids of the Nakhlak Group with other areas show the existence of a certain province in the southern margin of Eurasia from the eastern most to western most portion of Paleothetys Ocean. This distribution shows the bio-district distinction of Eurasia (in the north) from Gondwana (in the south) and also shows the boundary between Eurasia (at north) and Gondwana (at south) in northern Iran.