نصیر عامل

The kalasur_Kharil granitoid complex with Oligocene age, is located in SW Kaleybar of NW Iran, Alborz-Azarbaijan zone. The rocks are intruded into the Cretaceous volcanic and sedimentary rocks. The composition of plutonic rocks are consist of gabbro-diorite, diorite, quartz monzodiorite and granite. The major minerals in gabbro-dioritic and dioritic rocks are plagioclase, clinopyroxene, amphibole, biotite and major minerals in quartz monzodioritic and granitic rocks are potassium feldspar, plagioclase, quartz, amphibole and biotite. On the basis of mineral chemistry, the composition of clinopyroxenes is in diopside range. Amphibole minerals are calcic in study area. The calcic amphiboles indicates that the rocks of the studied area belong to type I granitoids. The Khari- Kalasour amphiboles are magnesio hornblende. The biotite in Kharil- Kalasur granite with Fe/(Fe+Mg)>3 is magnesio-biotite. The feldspar composition is albite-andesine in granite, labradorite, andsine and orthoclase in dioritic and quartz monzodioritic rocks. Mineral chemistry of the biotite, amphiboles and pyroxenes indicate that this rocks are calc-alkaline and have been crystallized in a subduction zone setting.

The studied area is located in the northwest of Iran, East Azarbaijan province, and at a distance of about 30 km from the north of Sarab city. This area is part of the structural zone of Alborz. Based on petrographic and field studies, the lithology of the area includes an intrusive mass of quartz monzonite porphyry, the mass of granodiorite porphyry, dykes branching from the mass of granodiorite porphyry, and basalts. The main mineralogy includes plagioclase, quartz, potassium feldspar, clinopyroxene, biotite, and amphibole, alteration minerals in the studied rocks include sericite, chlorite, kaolinite, and iron oxides and often have porphyric, glomeroporphyric and Poikilitic texture. The most important variations include phyllic, argillic, and propylitic zones. Sulfide minerals observed in the area are mostly pyrite, chalcopyrite, sphalerite, and molybdenite, which have been converted into iron oxides and hydroxides (hematite) at some points. The mineralized texture is mainly scattered grains and veins. Examining the changes of rare earth elements and rare elements of porphyry masses shows positive anomalies of elements Li, Pb, Th, and U and negative anomalies of elements P, Zr, Ti, and Nb. A specific enrichment of LREE/HREE elements can be seen. The ratio of Eu/Eu* in altered samples is lower than that of healthy samples, and the ratio of Ce/Ce* is almost the same for healthy samples and most of the altered samples. In addition, the subtraction factors of (La/Yb)N, (La/Sm)N, and (Gd/Yb)N in altered samples are higher than in healthy samples. Light rare earth elements show an increasing trend and heavy rare earth elements have increased and decreased during the region's transformation process. The enrichment of U and Th elements is probably due to the prevailing acidic conditions and surface absorption by clay minerals and also due to the presence of zircon in the mineral network. Elements with high field strength show enrichment in most of the altered samples compared to the source rock, and only the Hf element shows depletion.

The mud volcanoes of Sivan region are unique phenomena that are closely related to the folded and fine-grained sedimentary units of the Miocene. These mud volcanoes are in the form of eroded and inactive or semi-active cones, as well as mud ponds in the region. The results of the analysis of the sediment samples, in terms of texture, place them in the mudstone and clayey silt groups, in the Folk and Shepard classifications, respectively. Quartz, feldspars, mica, various heavy minerals, clay minerals (Illite and chlorite) and rock fragments (metamorphic, carbonate and volcanic) are the components of these sediments. Mineralogical evidence indicates the origin of sediments from metamorphic and possibly volcanic rocks of the region. The amount of calcium carbonate in the mud samples varies between 19 and 45%, and accordingly, the sediments of the mud volcanoes are calcareous mud, argillaceous marl, and marl. The formation of Sivan mud volcanoes can be related to some factors such as the presence of fine-grained sediments of Miocene, the thickness of sediments, and the influence of overburden pressures and regional tectonics. Also, the presence of a hidden salt dome according to the geological map as well as surface features can be effective factor in the formation and activity of the mud volcanoes in this area. In terms of the composition of sediment, water and formation mechanism, these mud volcanoes are comparable to mud volcanoes on the margins of the Caspian basin, which can be related to their sedimentation-tectonic conditions.

The studied area is located in the northwest of Iran within the western Alborz- Azerbaijan zone. The host rocks of the studied xenoliths are basaltic andesite and andesite. Xenoliths in volcanic rocks include gabbroic and diorite xenoliths. The main minerals of xenoliths include plagioclase, amphibole and clinopyroxene with minor minerals including biotite, orthopyroxene and opaque minerals. The main texture of xenoliths is granular and microlithic porphyric. Based on mineral chemistry, the composition of plagioclase, amphibole, pyroxene and biotite is oligoclase to andesine, chermakite to hornblende, augite and stonite respectively. Based on AlIV value (less than 1.5), amphiboles of xenoliths are placed in the active subduction-related continental margin. The thermo-barometric measurement of xenoliths, using the amount of total aluminum cations, indicates a pressure of 5.8 ± 0.6 kbar and a temperature of about 802°C in the crystallization environment. The studied clinopyroxenes with sub-alkaline composition show good compatibility with magmatic arc tectonic environment. Also, clinopyroxenes are formed in low to medium pressures, which indicates their crystallization during magma ascent at different depths. The amount of ferric iron in clinopyroxenes indicates the high fugacity of oxygen magma. The clinopyroxenes of diorite-gabbroic xenoliths were formed at a pressure of 12 kilobars and a temperature of about 1050°C.

The study area is Tasuj region, in East Azarbayjan Province, which consists of the mountainous and Tasuj plain. The purpose of this study is identification the areas with high potential for subsidence, earthquake and landslide in the Tasuj region, based on the factors affecting their occurrence and using the hierarchical analysis process (AHP) method. In this study, the effect of groundwater drawdown and the risk of subsidence due to it were evaluated. The average amount of water table drawdown in the study area was calculated about 6 meters and areas with high subsidence risk were identified. For the mentioned hazard zoning, 15 criteria, such as water table, water table drawdown, slope, aspect, distance of stream, land use, elevation, lithology, distance of fault, earthquake depth, fault length, distance of epicenter, earthquake magnitude, distance of road and rainfall were used. According to the results of this study, the criteria of water table, distance of faults and lithology, respectively, have the greatest effect on the risk of subsidence, earthquake and the potential for landslide occurrence. Also, most of the areas associated with high risk of subsidence, earthquake and landslide are located in the central and southern parts of the plain, eastern and northern parts of the region and mountainous and steep areas in the north and east of the region, respectively. Therefore, by studying the resulting zoning maps and identifying high-risk points in the basin, their harmful effects on natural resources and other parts can be reduced.

In this study, some samples of bed sediments from Rasht rivers were obtained and 19 organochlorine pesticides (OCPs) were determined for specifying the contamination profiles, distribution characteristics, effective factors and hazard of carcinogenic compounds. OCPs as Persistent Organic Pollutants (POPS) haskhown vast distribution, persistence and accumulation in the environment. Their high toxicity to humans and non-target organisms are a significant threat to human health and biodiversity.

Identify and determine the concentrations of organochlorine pesticides analysis were conducted on bed sediment samples by liquid-liquid micro extraction method and then by gas chromatography flame ionization (GC-FID) and via external standard calibration curve drawing.

Based on the analysis, total concentration of OCPs is in the range of 2.6-60.2 ng/g, with an average of 20 ng/g. The main sources of pollution are Heptachlor, HCHs, DDTs and Endosulfans and highest contamination of the dominant pollutant DDE isomers belonges to sediments of Pir Bazar River.

The results are showed that there were various amounts of new and past entries. The analysis shows that the potential source of high levels of DDTs and HCHs residues of pesticides returns to the pastconsumptions.

The Saray volcano is located on the East of the Urmia Lake. This extinct stratovolcano mainly consists of Leucitite lavas and related pyroclasts. Dykes with composition of Leucite phonolite, Lamprophyre, Trachyte and microsyenite intruded into leucitite. Field evidences indicate that minette and trachytic dykes intruded into each other. A microsyenitic stock and dykes outcrops in the central valley of this volcano. The trachytic pyroclasts eruption is the last activity of the Saray volcano and probably caused the destruction of volcanoe’s caldera and formed its current shape. Leucitites maimly consist of leucite and clinopyroxene phonocrysts, minettes consist of biotite and clinopyroxene phenocrysts and trachytes consist of biotite, sanidine and clinopyroxene phenocrysts. The Saray magmatism has potassic to ultrapotassic nature and its geochemical features indicate that this magma should be originated from a micaceous garnet clinopyroxenite mantle. The coexistance of leucitite, lamprophyre and trachyte, could not be explained only by the function of fractional crystallization in leucitite magma. Sanidine is the most abundant feldspar in the Saray volcano. Sanidine megacrysts crystalize in a medium size magma chamber with continuing temperature cycling, so that the magma temperature remains close to the liquidus temperature of the K-feldspar for a long time.

The studied volcanic rocks are located in 35 km North West of Tabriz and consists of dacite, andesite, basalt and basaltic andesite. Based on structural geology evidences, this area is part of west Alborz – Azerbaijan zone. Plio - Quaternary volcanism is started with explosive eruptions of acidic and intermediate materials and in last and young stage basaltic lava erupted from faults and fractures that are visible with layered structure. Prismatic basaltic lavas covered pyroclastic rocks and andesitic lavas. The main constituent minerals in these rocks are olivine, plagioclase, amphibole and pyroxene. In the diagram to determine the magmatic series, samples belong to two magmatic series calc-alkaline and alkaline and show characteristics of bimodal magmatism. Studied volcanic sequence show a reverse volcanic series that it is results of characteristics of bimodal volcanism. In spider diagrams which normalized with chonderite and primitive mantle amounts, these rocks show enrichment of HREE and HFSE elements and depletion of LREE and LILE like Ti, Nb and Ta (TNT). According to the trace elements diagrams La to La / Sm and La / Yb to Yb ratio, magma genesis can be formed from a low rate of partial melting of garnet lherzolite mantle and with ascending and emplacement of magma in the upper level of the crust partial melting of crustal rocks produced acidic and intermediate volcanic materials. Tectonomagmatic diagrams show that these rocks formed in post collision volcanic arcs.

The study area is located about 30 km northwest of Maragheh in East Azerbaijan. The lamprophyric dyke intruded the Shemshak sedimentary rocks. Based on stratigraphic evidences, the age of dyke is probably Early Cimmerian. The principal minerals of the lamprophyric dyke consist of plagioclase (andesine -oligoclase), biotite (eastonite), phlogopite, olivine and clinopyroxene (diopside) with ocellar texture. The average chemical composition of clinopyroxene and plagioclase is En42.3, Wo46, Fs11.7 and Ab51.74, An30.92, Or17.34 respectively. According to the mineralogical and geochemical evidences, the studied lamprophyre samples are kersantite belonging to calc-alkaline lamprophyre.The plotted spider diagrams for the rock samples indicate the light rare-earth elements (LREE) and incompatible elements enrichment compared to heavy rare earth elements (HREE). The parent magma is probably generated from garnet lherzolite mantle with low rate partial melting. The studied lamprophyre dyke formed in intraplate and post collision environment which translocated possibly in basins and ruptures in related with fault systems.

The study area is situated in the south of Sahand volcano in the northwest of Iran. The volcanic rocks in this area are part of young activity of Sahand volcano, erupted as flow lavas and tuff or tephra units consisting of ash, punce, lapilli, agglomerate and volcanic breccia which overlay the Pliocene sedimentary units. The r composition of rocks is predominantly dacite with porphyry texture with fine grain matrix and glassy and trachyte textures. Geochemical data show that the subalkaline dacite rocks is adakitic composition and are characterized by high amount of Sr, LREE, LILE and high ratios of Na2O/K2O with differentiated pattern of REE, low ratios of HREE and Y. Depletion in Nb, Ti and HREE and enrichment in LILE and LREE are all evidences of subduction adakitic magmatism. The adakitic rocks in the study area were probably formed by slab break off and melting of oceanic isolated crust. Post collisional magmatism related to the Neotethyan subduction caused the formation of adakitic magmatic rocks in the south of Sahand and the northernmost of the Uromieh-Dokhtar magmatic zone.