Sedimentology
Sedigheh Amjadi; Hamid Alizade Lahijani; Mohamad Hosein Mahmudy Gharaie; Razieh Lak; Nick Marriner
Abstract
AbstractAlthough the second deadliest tsunami in the Indian oceans was triggered in the Makran zone, our knowledge in regard to the number of tsunami events through the Holocene is negligible. In this study the sedimentary environment palaeo-tsunami have reconstructed and identified by Gulf of Oman deep ...
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AbstractAlthough the second deadliest tsunami in the Indian oceans was triggered in the Makran zone, our knowledge in regard to the number of tsunami events through the Holocene is negligible. In this study the sedimentary environment palaeo-tsunami have reconstructed and identified by Gulf of Oman deep sea cores. Sedimentation trends and effective factors on seabed sediments transportation by tsunami events were identified based on sedimentological parameters, foraminifera shells identification, magnetite susceptibility changes and palaeo-ocean currents reconstruction. The results of this study demonstrated that evidence of sea bed sediments transportation due to the strong earthquake in the Gulf of Oman were different through time and location. The palaeoenvironmental studies and historical tsunami events suggested at least five considerable submarine landslides through last 2500 cal. yr BP. The number of the events have dramatically increased during last thousand years. Rendering to the results and historical data, almost seven strong earthquakes were happened in the studied area that their traces have illustrated in this study. According to the city expansion in the southeast coast of Iran and increases number of earthquake events in the Makran zone adoption management plans in order to decrease probably tsunami damages are required.
Geological Environment and Engineering
Farah Rahmani; Abdolreza Jafarian; Razieh Lak; Javad Esmaeili
Abstract
The present study aims to determine the concentration of heavy metals and toxic metalloids in rice of Sari paddy fields in the Mazandaran province of Iran. In this study, sampling was performed from 32 stations of the rice seed section. The soil-plant relationship was investigated in 6 stations using ...
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The present study aims to determine the concentration of heavy metals and toxic metalloids in rice of Sari paddy fields in the Mazandaran province of Iran. In this study, sampling was performed from 32 stations of the rice seed section. The soil-plant relationship was investigated in 6 stations using samples taken from rice soil and other plant parts such as roots, stems, leaves, and bran. Soil and plant samples were prepared using ICP-OES and ICP-MS methods, respectively, and then analyzed chemically. The results of the chemical analysis of rice samples showed that the mercury (Hg) concentration is usually about 0.07 ppm. However, it reaches about 0.09 ppm in some points (30% of the samples). The mean concentration of lead (Pb) is 0.91 ppm, which is close to its allowable limit. In some samples, elements arsenic (As), cadmium (Cd), nickel (Ni), and zinc (Zn) are different from normal concentrations. The study results attribute the origin of lead elements to the use of chemical zinc fertilizer in rice fields and paddy fields, as Pb concentration in areas with zinc (Zn) fertilizer consumption is about 3.99 ppm. The as concentration in Isa Khandagh is 1.15 ppm, suggesting a high deviation from the normal level. In addition, the concentration of trace elements in rice crops in different regions of Sari city compared with rice crops in some foreign cities shows a high correlation for chromium (Cr), cobalt (Co), Arsenic (As), magnesium (Mg), manganese (Mn), sodium (Na), and Zinc (Zn).
Hydrology
Ghazaleh Mohebbi Tafreshi; Mohammad Nakhaei; razieh Lak
Abstract
Land subsidence is a nonlinear and complex process that data-driven computational intelligence models can model it. In this study, the accuracy and efficiency of hybrid fuzzy logic gene expression planning hybrid model in estimating land subsidence risk and its factors in Varamin aquifer standardized. ...
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Land subsidence is a nonlinear and complex process that data-driven computational intelligence models can model it. In this study, the accuracy and efficiency of hybrid fuzzy logic gene expression planning hybrid model in estimating land subsidence risk and its factors in Varamin aquifer standardized. For this purpose, after selecting and gathering information from 15 factors affecting the subsidence event based on research records in the GIS environment, they were first standardized by fuzzy membership functions and then gene expression programming method was used to integrate the layers. Finally, using seven important statistical benchmarks based on radar image data, the model was validated in 4 different scenarios in input data and operators. The results showed scenario 1 with input parameters of bedrock level, Debi of pumping wells, groundwater drawdown, geology and operators, +, - ×, ÷, sqr, exp, Ln, ^ 2, ^ 3,3Rt, sin, cos, Atan, is the best model in training and testing. Accordingly, the groundwater drawdown parameter had the highest effect on land subsidence in the study area.
behnam pashazadeh; Davood Jahani; razieh Lak; Hamid nazari; masoud zamani pedram
Abstract
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 ...
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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.
K. Nezhadafzali; R. Lak; M. Ghoreshi
Abstract
Mud volcano is a natural and spectacular phenomenon that usually appear in form of a dome but some are found as a basin. Mud volcanoes comprise a mixture of water, gas and mud. They are found in most parts of the world, particularly in the Alps and Himalayas belts. In Iran, most of the mud volcanoes ...
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Mud volcano is a natural and spectacular phenomenon that usually appear in form of a dome but some are found as a basin. Mud volcanoes comprise a mixture of water, gas and mud. They are found in most parts of the world, particularly in the Alps and Himalayas belts. In Iran, most of the mud volcanoes appear in coastal plains of the Caspian and Oman Seas. Mud volcanoes are known as indicators of oil and gas resources, and they are used to predict the existence of oil and gas reservoirs in Earth subsurface. The Napag mud volcano, as the largest and most active one in Iran, is located on the northern coast of the Oman Sea and is an interesting natural occurrence in the country. It is associated with a 39-m-high cone-shaped hill and several active and inactive vents. Mud eruption with different rates occurs usually every 3-5 minutes, and flows out from the western disrupted side of the edifice downslope toward the surrounding plain. In this research, a sediment sample was taken from the mud-flow during the field work, then analyses was analyzed for major, accessory and trace elements using ICP-OES machine in the laboratory. In addition, an analysis of the grain size of the sediment sample was carried out and the data were processed by the SPSS software. Results show that the sediment particles are of clay and silt in size. Al and Fe elements constitute 89.8 and 4.4 % of the sediment, and their high frequency is related to the high percentage of clay in the sediment. The evolution of the Napag mud volcano was investigated in three different stages: (1) Explosive, (2) Effusive (fast eruption with high rate), (3) Extrusive (slow and gradual eruption of material with high viscosity).
A. Pouresmaeil; F. Hadavi; R. Lak
Abstract
In this study, a core with 10.5 m lenght and in shallow water in Bandar Abbas (Shahid Rajaee Port area) was studied based on calcareous nannoplankton. In this study, 52 samples of sediment cores were taken and prepared. Most species were photographed by light microscope. For the first time 21 genera ...
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In this study, a core with 10.5 m lenght and in shallow water in Bandar Abbas (Shahid Rajaee Port area) was studied based on calcareous nannoplankton. In this study, 52 samples of sediment cores were taken and prepared. Most species were photographed by light microscope. For the first time 21 genera and 35 species introduced in this area. In the core mentioned Gephyrocapsa oceanica and Emiliania huxleyi are the dominant taxa, based on the abundant presence of these species can be concluded that the Persian Gulf basin is a marginal sea in the lower latitudes and shallow areas have been formed and in this area productivity of nannoplankton is high.
K. N. Afzali; R. lak
Abstract
United Arab Emirate has recently started to build some artificial islands in the southern part of the Persian Gulf. Constructing of these Islands, such as each marine structure, have special effects on the morphology of the sedimentary Basin. This investigation focused on the documentation of morphological ...
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United Arab Emirate has recently started to build some artificial islands in the southern part of the Persian Gulf. Constructing of these Islands, such as each marine structure, have special effects on the morphology of the sedimentary Basin. This investigation focused on the documentation of morphological and environmental effects of making artificial islands by the UAE in the Persian Gulf. This research is based on remote sensing studies and sedimentology investigation. Remote sensing studies carried out with comparing satellite data related to 1998, 2003, 2007 and 2008. Sedimentology investigation of the three sediment samples taken from the coastal part of the artificial islands was carried out. The deliberations indicate that construction of these islands have negative effects on geomorphological features in coastal part of the Persian Gulf in UAE region. The Sedimentation around the islands leads to the reduction of water depth. The kind of the sediment is usually carbonates and their origin in the western part of the islands is affected by marine longshore currents. However, there are two sources proposed for the sediments in the eastern part of islands; intrabasinal (direct precipitation) and detrical. The construction of linear barriers along the coast leads to the building of restricted lagoons between the coast and barriers. It is estimated the rate of progradation of the coast (sea ward migration of the shoreline) is 120 m from 2008 to 2009.
K. Nezhadafzali; R. Lak; M. Sarvati; F. Bayatani
Abstract
Mud volcanoes are natural and site-seeing phenomena in the world, particularly in the Alps and Himalayas belts. Mud volcanoes usually appear in form of a dome or a pool. The mud volcanoes comprise water, gas and mud. with plenty of applications, like tourism, mud therapy, supplying of essential ...
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Mud volcanoes are natural and site-seeing phenomena in the world, particularly in the Alps and Himalayas belts. Mud volcanoes usually appear in form of a dome or a pool. The mud volcanoes comprise water, gas and mud. with plenty of applications, like tourism, mud therapy, supplying of essential body trace elements, and their usage as mud for pottery. In Iran most of the mud volcanoes appear in coastal plains of the Caspian and Oman Seas. A mud flow was formerly found between Minab and Jask in Hormozgan Province. These types of exclusive, beautiful and natural phenomena require more attention by tourism industry. On the other hand, mud flow must be introduced as the most important geotourism phenomenon of northern coast of the Oman Sea. In this research, after data collection, including topography and geology maps, AIRS satellite data and aerial photos, remote sensing verifications were implemented. Then, mud flow determination was completed by field work studies and checking. A sediment sample was taken from each mud flow in the field work, then analyses of major, accessory and trace elements were carried out by using ICP-OES. About 30 small and big mud volcanoes around of Gavak mountain and 6 mud volcanoes at Gatan and Tojak area were determined in Hormozgan province that they have not been introduced before. The biggest mud volcanoe (Aryana) has cone with 73m hight at Gatan area and the smallest one has cone with less than 1m at Gavak area. Meantime, hydrogeochemical studies or determination of the percentage of available elements for all mud volcanoes were implemented. Since this geomorphological phenomenon indicates tectonic activity of a region, hence there is a possibility of mild earthquake and faulting occurrence. This issue must be considered in construction of buildings and certain fixed structures, such as bridges. Emitted gases through mud volcanoes relatively indicate the internal conditions of the Earth, particularly existence of oil and gas reservoirs. Mud flow is an index for availability of oil and gas reservoirs. They are used for prediction of availability of these reservoirs inside the Earth.
F. Fayazi; M. Nahkaei; R. Lak
Abstract
Maharlou lake located in southwest of Iran is an intra-continental sedimentary basin. Its area is about 280 km2 extended with an average water depth of 1.5 m during wet seasons. The water level in the lake is controlled by several factors such as runoff volume from Maharlou catchment, ...
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Maharlou lake located in southwest of Iran is an intra-continental sedimentary basin. Its area is about 280 km2 extended with an average water depth of 1.5 m during wet seasons. The water level in the lake is controlled by several factors such as runoff volume from Maharlou catchment, underground water seepage, and direct rainfall over the lake and also evaporation. Generally, hydrochemical analysis of water resources showed that the water types are mainly bicarbonates and sulfates due to geology of the surrounding areas. Hydrochemical investigation has been carried out for a time period between 1975 and 2002 using previously published analyses together with new collected water samples. 230 samples were collected during summer 2001, summer 2002 and spring 2005. Results show a change in the brine type through time; with an Mg-SO4-Cl type in 1970 to an Mg-Cl-SO4 type in 2001 and currently Na-Mg-Cl brine type, in recent time, which is comparable with Great Salt Lake in USA. Due to changes in diluted water compositions from HCO3 ≥ (Ca + Mg) to HCO3 (Ca + Mg), the path of brine on the Eugster and Hardie flow diagram changes from row III to the path II, indicating that the bicarbonate water comes into the lake from a fault occurring in the lake floor.
