KHARAZMI JOURNAL OF EARTH SCIENCES (JOURNAL OF SCIENCE (KHARAZMI UNIVERSITY))
Year:2019 | Volume:5 | Issue:1 |Papers Count:7

Understanding of the geological characteristics of artificial stone is of particular importance. Appearance, size and dimensions, specification of particle surface and minerals forming aggregates are among the characteristics of rock materials that affect the homogeneous and cladding environment. Volume variations, water absorption, resistance to atmospheric agents and wear resistance are the most fundamental features of engineering stone in artificial stone. In this research, to investigate and compare the resistance properties (Uniaxial Compression, Brazilian, Point Load, Ultra Sonic) and the physical properties of artificial stones made with additives (polyester resin, vinyl ester resin, glass fiber and aggregate type) with three granite samples, we will cover the Alamut granite, Takab granite and Nehbandan granite. The results of the study show that the glass of fiber glass samples compared to non-woven glass made of resin and aggregates, has more 15% of tensile strength, 14% of uni-axial compressive strength and 12% of the point load index. As well as, resistance of samples made with a leaden resin is 1. 64 times more than polyester resin specimens. Based on this study, the mixing plan and percentage ratio combination is the most important principle in the strength and strength of artificial stone

The Eocene volcanic rocks exposed in the NW Sechangi area of Lut block, include pyroclastic deposits and lavas. These volcanic rocks are basalt, basaltic andesite, andesite, andesite-trachyandesite, trachydacite, dacite and rhyolite-ignimbrite in composition. Based on our field observations, the volcanic rocks erupted in four stages in the aquous to subaerial environments. The volcanic rocks are exposed as alternation of acidic and basic-intermediate rocks resembling bimodal volcanism. According to our petrographical investigations the acidic rocks include pyroxenite microenclaves which probably originated from the remains of a sub-continental lithospheric mantle. In the discriminating magmatic diagrams the volcanic lavas show shoshonitic to high-K calc-alkaline trends. In the normalized REE patterns and spider diagrams they display enrichments of LREE and LILE relative to HFSE, comparable to subduction-related volcanism. In the tectonomagmatic diagrams they cluster within the continental margin field. Interpretation of the geochemical diagrams indicates that the basic-intermediate volcanic rocks were produced by partial melting of lithospheric mantle which were previously enriched by the subduction components (fluids-melt) effects of which may not be distinguished from the crustal effects. The acidic rocks record some crustal elements which indicate involving of the crust in the generation of these rocks. It appears that after the closure of the Neotethys branches in Late Cretaceous and subsequent lithospheric thickening in the Lut block, the Eocene volcanic rocks in the Sechangi area were formed in collision extensional environment.

Niabad-Qalaje ophiolitic complex is part of Sarvabad ophiolites in Kurdistan that exposed in northwest of Iran and the north of Kermanshah Ophiolites. The complex located in north of Zagros orogeny, consists of lens form, tectonically dismembered ophiolitic sequences located along the main Zagros trust. The ultramafic part includes serpentinized dunite and wherlite, serpentinite and chromitite that outcropped as consecutive lenses. Small lentiform chromitites present podiform and shear fabrics. The major minerals in peridotites are olivine (Fo= 88-91), clinopyroxene and chromian spinels. Low Ti value and high content of Al and Cr# in peridotite chromian spinels reveal a high rate of partial melting (25-35%). Mineral chemistry and whole-rock chemistry clearly indicate that the Kurdistan ultramafic cumulates and chromitites record an episode of boninitic magmatism. Boninitic melts in Niabad-Qalaje ophiolites were formed by partial melting of a depleted peridotite which made up the residual mantle after MORB-type melt extraction. The chemistry of peridotites shows the abyssal to supra-subduction zone source. Comparing the lithological and geochemical characteristics of the studied ophiolites with some other complexes in the world denotes that the Kurdistan ophiolitic complex formed in a fore arc basin close to the Sanandaj-Sirjan zone continental margin.

In the southeast of Iran, titaniferous magnetite deposits associated with the gabbro rocks occur in Kahnuj ophiolitic complex. Mineraloghraphy studies have revealed the primary and secondary ore mineral consist of titanomagnetite, ilmenite, hematite, goethite, martite, pyrite, chalcopyrite, pyrrhotite and silicate minerals (plagioclase, pyroxene, hornblende, olivine, alkali feldspar). Trellis-sandwich textures and ilmenite-titanomagnetite intergrowths are resulted from oxidation of former Ti-rich magnetite at different temperatures. Chemical analyses show that the ilmenite and magnetite (titanomagnetite) contains 46. 51 to 52. 68 and 4. 00 to 19. 71 wt. % TiO2 and 1. 00 to 2. 98 and 0. 00 to 1. 74 wt. % V2O3, respectively. The ulvö spinel (Mol % Usp) (Fe2TiO4) in titanomagnetite shows a composition ranging from 4. 58 to 56. 87 wt. %, and ilmenite lamellae are varying thickness and ilmenite type 1 to 3 contain of 88. 23 to 93. 94, 93. 04 to 99. 80 and 99. 09 to 99. 73 wt. % of the ilmenite (Mol % Ilm), respectively. Compositions of intergrowth Tm-Ilm pairs (type 2) were plotted on T/fO2 diagrams. The Tm-Ilm pairs show varying degrees of re-equilibration to subsolidus temperatures (551 to 830° C) and fO2 (-21. 6 to-23. 97). The Tm-Ilm pairs from Dar Gaz cluster around the QFM buffer curve for 1. 5 kbar total pressure.

Lat-Blukan district situated on N-Qazvin and western Alborz zone contains various extrusive and intrusive bodies with Eocene age. They are divided into three main facies that are volcaniclastic deposits (including tuff, lapilli tuff, agglomerate, tuffaceous sandstone and shale and also the carbonate intercalations), the trachyandesitic lava flows and subvolcanic bodies (including dioritic bodies, dacitic domes and parallel dyke swarms). Because of many sedimentary structures, such as layering and graded bedding together with middle Eocene microfauna in the tuffaceous deposits, a shallow-depth sedimentary basin interrupted by the explosive volcanic eruptions is concluded. On the other hand, the overlying lava flows were formed by the subaerial effusive eruptions through vertical fractures (i. e., feeder dykes) that is verified by the columnar jointing and soil horizons under many lava flows. Finally, the intrusive facies, including the dacitic domes and dioritic bodies are the latest stage of the magmatic cycle in the region that their intrusions were controlled by the geologic structures. The main NW-SE trend of the parallel dyke swarms provide a NE-SW local extensional environment controlled the intrusion of dyke swarms (s3) with prominent NW-SE trend parallel to s1. Moreover, it seems that the microdiorite intrusion and dacitic dome in Lat area were emplaced in the local tensional curved spaces of the Lat strike-slip fault and also the NE-SW sinistral strike-slip faults. On the other hand, the dacitic dome of the Bolukan area was likely intruded in the tensional spaces of two reverse strike-slip faults. Thus, it seems that the dyke swarms had been emplaced forcefully; whereas the microdiorite bodies and dacitic domes were intruded by the ballooning and passive mechanism.

Most local people in the agricultural areas of Sistan and Baluchestan Province (Iran), generally consume shallow groundwater from farm wells. This study aimed to assess the water quality and health risk potentially of As, Pb, Cr and Ni for drinking purposes in Zarabad aquifer. Also the geochemical processes controlling chemistry of Zarabad aquifer were studied. Piper diagram shows two major hydrochemical facies of Na-Cl/SO4 and Na-SO4/Cl in the groundwater samples. Based on hydrogeochemical results (Composite and Gibbs diagrams), chemistry of groundwater is influenced by water-rock interaction, evaporation and ion exchange. Arsenic, Ni and Pb for 27, 53 and 80% of the groundwater samples show higher concentrations than the maximum acceptable limit for drinking water. According to the WQI values all of the water samples were considered unsuitable for drinking purpose. The results of principal component analysis (PCA) indicate that As, Ni, Pb and Cr have more influence from anthropogenic sources such as application of fertilizers and pesticides in the agricultural lands. The result of health risk assessment shows that the consumption of heavy metals (such as As and Pb) contaminated groundwater poses an emerging health threat to the populations in the study area, and hence needs regular monitoring and management measures.

This paper focuses on the application of Geoinformatic methods (simultaneous using of remote sensing, geographic information system, global positioning system, terrestrial and aerial photogrammetry) in optimal operation and exploration risk reduction of oil and gas reservoirs. To approach the purpose, two aspects of remote sensing (satellite image) and terrestrial and aerial photogrammetry have been investigated. The main role of satellite images is usually structural identification and alteration detection using geometric and radiometric analyses. Lithology investigations of the area are studied together with hydrothermal alteration of rocks, hydrocarbon index and geobotany model. Photogrammetric analyses are performed with the goal of qualitative interpretation of the scene and creating 3D models for the desired area. In the present research, the Saracheh area in Qom province, which is according to geological evidence and exposed hydrothermal alteration zones, has been studied. To achieve this goal, image processing of ASTER multi-spectral imagery of Terra satellite was utilized. Moreover, classification methods by means of SAM and SID algorithms for detecting mineral alteration zones and lithological grouping have been carried out. Finally, extracted information layers of terrestrial, aerial and spatial data were combined together to validate the results with independent data. The desired oil and gas potential map is produced according to multi-criteria decision making (MCDM) procedure. Field surveys and interpretation of photogrammetric photos and other evidences indicate that the potential mapping of the hydrocarbon resources is accurate and the results are consistent with the field observations at a high level of reliability (more than 75 percent accuracy).