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مرکز اطلاعات علمی SID1
اسکوپوس
دانشگاه غیر انتفاعی مهر اروند
ریسرچگیت
strs
Author(s): 

MOHAMMADI A.

Journal: 

Journal of Arid Biome

Issue Info: 
  • Year: 

    2010
  • Volume: 

    1
  • Issue: 

    1
  • Pages: 

    68-78
Measures: 
  • Citations: 

    0
  • Views: 

    2354
  • Downloads: 

    400
Abstract: 

Playa lakes are an important source for aeolian and dust storm sediments, because of their location in low land, arid and desert regions with strong wind systems and existence of fine and unconsolidated sediments. Jazmourian playa (Hamun Jazmourian) is an ephemeral lake with a large catchment has located in the Southeast of Iran. During the last 10 years, the playa was dried because of drought. In this study, 26 surface sediment samples were taken for SEDIMENTOLOGY and sedimentary geochemistry analysis. Sieve for the samples, laser, calcimetry, mineralogy, morphoscopy, morphometry and chemical analyses have been done. Results show that the sediments with the size of silt and clay are dominated which are potentially suitably for wide distance and long time transportation. The most important minerals are calcite, quartz, feldspar and halite. Distributions of minerals in playa have a regular pattern. Montmorilonite, chlorite and Illite are the major clay minerals whereas Kaolinite is the minor one which is autogenic. Sedimentary geochemistry results show there are two main debris sources for the elements including igneous, ophiyolite omelange, and evaporate sediments. Elements Ca, Sr and Na mostly precipitate by chemical process in the playa. Because of morphology, climatology and SEDIMENTOLOGY conditions, the Jazmuriyan playa is an important source of aeolian sediments and dust storm in the southeast of Iran and southearn Asia.

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Journal: 

APPLIED SEDIMENTOLOGY

Issue Info: 
  • Year: 

    2016
  • Volume: 

    4
  • Issue: 

    7
  • Pages: 

    82-100
Measures: 
  • Citations: 

    0
  • Views: 

    1060
  • Downloads: 

    404
Abstract: 

Tsunami study as one of the most serious forms of coastal hazards, is favored by many engineers, planners, and politicians. Depositional effects of the tsunami subdivided to sedimentary and geomorphic landforms. This article is about the sedimentation processes associated with tsunami inundation in the northern coast of Oman Sea (Makran). Tsunami inundation features of flooding are very diverse. At first, this paper presents a conceptual model of coastal tsunami sedimentation processes deduced from the case studies and outlines diagnostic features of tsunami deposits, and then reviews the presence or absence of these features in a storm deposits. Random pits drilled in some of the water entries on the northern coast of Oman from Chabahar to Beris and the sedimentological sequence is investigated in them. Experiments such as granuluometry by wet and dry sieve, hydrometry, calcimetry, and X-ray Diffraction (to recognizing minerals) done. Some pits shows finning upward sequences, Rip Rap structure, shell fracture accumulation, and sudden change in sediment. According to the observed sedimentary structures, sorting, tilt, percentage of calcium carbonate and terrigenous debris, possible deposit of tsunami are detected. The aim of this study has also been to evaluate the ability of SEDIMENTOLOGY in detecting evidence of tsunami sediment off the coast of Makran.

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Author(s): 

NAKHAEI M. | FAYAZI F. | MAHMOODI A.

Issue Info: 
  • Year: 

    2011
  • Volume: 

    9
  • Issue: 

    2
  • Pages: 

    447-461
Measures: 
  • Citations: 

    0
  • Views: 

    788
  • Downloads: 

    133
Abstract: 

Zolachay river has an area about 960 square kilometer located in south-west of Salmas city. The evaluation of shape and drainage density of catchment area shows a dense catchment with high flood discharge and erosion potential. The texture variations and particle size growth are investigated at 84 locations in river catchment area. The particle size increases exponentially toward the river downstream. The results indicate that particle size growth is due to tributary entry and lithology changes. In overall view the river sediment particle size distribution shows bad sorting with positive skewness. It is used the trend of particle size mean and median for selecting the proper SDR method. Also the river suspension sediment loads estimated approximately 105 ton per day using the Yang method.

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گارگاه ها آموزشی
Issue Info: 
  • Year: 

    2012
  • Volume: 

    7
  • Issue: 

    4
  • Pages: 

    289-298
Measures: 
  • Citations: 

    0
  • Views: 

    1588
  • Downloads: 

    886
Abstract: 

This research studied the coastal regions of southern Sistan and Baluchestan Province, which play a significant role in the international trade, Coastal management and marine industries. Determining suitable lands is very important for the development and construction of marine structures such as fueling, fishing, commercial jetties and coastal ports without environmental pollution. The research uses the existing references and documents in libraries, field and survey research method, and collecting coastal sediment samples from both surface and depth. By collecting thin sections, the sediments of the area are studied and their types are determined. Finally, combining these two sources of information, potentially suitable and unsuitable areas for the construction and development of jetties, ports and fuelling jetties are determined. In this study, it was shown that factors such as fluctuations in the sea level, tectonic processes, climatic atmosphere, hydraulic processes, especially tidal currents, human interference, and construction activities in the jetties and these coastal regions are the most destructive and constructive forces at work in the coastal regions. It was also revealed that Chabahar and Pozm coasts are clear indications of retrograde beaches of advanced sea. Oman coastal regions are exposed to two groups of marine and land factors due to the continuing uplift and subduction zone processes. Geological reasons are considered as the main factors. The rock units, affected by alteration processes such as dissolution, degradation and alteration of its components, have eroded severely. This fact makes the beaches prone to shock waves and local loading. In some places such as western Passabandar and eastern Ramin, these factors alone caused the separation and collapse of the rocks and, as a result, the withdrawal of the coast. While in some other areas, like sea walls separating the Pozm and Chabahar and Goater coasts, hydrodynamic factors such as waves' effect climatic conditions, monsoon winds, and wind erosion are the complementary factors in the erosion and the withdrawal of the rocky beaches.

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Issue Info: 
  • Year: 

    2019
  • Volume: 

    4
  • Issue: 

    4
  • Pages: 

    435-456
Measures: 
  • Citations: 

    0
  • Views: 

    585
  • Downloads: 

    216
Abstract: 

Introduction: Sedimentary environments are the best place to keep records of past events and evidence of fundamental events occurring on the surface of the earth within sedimentary units and their discontinuities. The identification and separation of these sedimentary units have often been the goal of many geological projects with different scientific and practical objectives. Detection of the alluvial deposit has always been of high importance when combined with their study. These hybrid studies are usually carried out in direct (sampling) and indirect methods (geophysical methods). In previous studies, in almost all researches, the necessity of carrying out SEDIMENTOLOGY studies to better interpret the identified sequences and their adaptation to GPR studies has been emphasized by the researchers. This combination of studies, in addition to separating different units in terms of grain size, may include other factors such as the presence the quality and depth of fluid (ground water and water table), uniformity of particle size (sorting), particle size, and sedimentary structures. The main objective of this research is to identify sediments and ambient environments of alluvial soils by integrating the data from sedimentation from wells and GPR. The study area is located in Guilan province, between Kouchesfahan and Lasht-e-Nesha cities in the coastal plain of the Caspian Sea. The climate of the study area is humid and the annual rainfall is an average of 800 mm. From geomorphology point of view, the northern boundary of the Alborz is in accordance with the cluster of tertiary deposits and the coastal plain of the Caspian Sea. Under the sea terraces and alluvial plain covers, there are the Miocene-Pliocene-Quaternary marine rocks that have been displaced by the retreat of the Caspian Sea. Material and Methods: Firstly, GPR data (using 100 megahertz antenna, MALA) was taken to 11 km long land along the Kouchesfahan road to the Lasht-e-Nesha. Then, according to the radar profiles, they were drilling 7 sedimentary boreholes for media depth 2. 7m to combine with SEDIMENTOLOGY data. Global Positioning System is used to determine the location. the resulting data for the processing stages entered the Reflex-W software. After performing the necessary processing considering the radar facies and the depth of penetration of the waves in the radar profiles, suitable points for drilling boreholes were selected for a sampling of subsurface sediments (7 stations). The average depth of the drilled boreholes is 7. 2 m. 42 Sediment samples were taken in each well based on the visible changes, including sediment type, grain size, color, moisture, and organic matter content. In the laboratory, grading experiments were carried out after the preparation of the samples (drying and separating organic matter), direct measurement of the dimensions with morphoscopy, dry sieving, and hydrometric method. In addition to the initial analysis of grain size, other statistical parameters such as the average of diameter, mean, sorting, skewness were measured. Results and Discussion: Investigations have led to the identification of five radar facies (Reflectors no-continuous undulating with concave-convex pattern, Reflectors continuous with concave-convex pattern, Reflectors no-continuous with different angle, Reflectors no-continuous parallel with low angle, Reflectors no-continuous with low angle and attenuation high and nine sedimentary facies; silty very fine Sand (Zs), fine Sand (s), sandy Gravel (sG), gravely fine Sand (gS), organic matter (O), silty coarse Sand (zs), coarse Sand(S), muddy slightly gravelly sand (g)Ms, which represent different parts of the river environment, including the river canal and floodplain. In this region, the amount of fine-grained particles and organic matter increases from the south to the north. The facies are likely to be part of the old channel of the Sefidrud River when the channel has been redirected to the east. Changes in the percentage of grain size in the boreholes have irregular variations, which the number of fine grain particles is increased from the upstream to downstream of the region. Grains tend to be coarser from the bottom to the top of the boreholes and finer toward the shore. Sorting are bad and very bad in most samples, which indicates the deposition of finer grain particles among coarse grains. From the upstream side, in most drilled boreholes, sediments show a finning and a coarsening upward sequence that indicates the energy fluctuations of the environment over time. Conclusion: The results of this study showed that wet, fine-grained with high organic matter content environments cause the destruction of the wave and including the radar method's limitations. Also, in urban environments and through the passageways, vehicle overpasses and power rails affect radar profiles and cause the radar profile to be illegible. In the studied area, the depth of effective influence of the waves is not more than 3 meters. In this research, based on valid scientific classification, 5 radar facies and 9 sedimentary facies related to different sedimentary environments were identified. The results showed that radial facies, with respect to depth, particle size, moisture, organic matter and evaporates content limitations, can be very good for identification of various sediments, especially at low and near depths. By performing this research and matching the sedimentary and radial facies, the ability of the two methods in another interpretation was also identified and such adaptations can be applied in other areas with great confidence.

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Issue Info: 
  • Year: 

    2015
  • Volume: 

    1
  • Issue: 

    2
  • Pages: 

    7-8
Measures: 
  • Citations: 

    0
  • Views: 

    132191
  • Downloads: 

    23290
Abstract: 

Extended Abstract: Introduction: Geological time has been evaporited sediments form by solar-driven concentration of a surface or nearsurface brine. Large, thick and extensive deposits were dominated by rock-salt (mega-halite) or anhydrite (mega-sulfate) deposits tend to be marine evaporites and can be associated with extensive deposits of potash salts (mega-potash). Examinations of sedimentologic and mineralogic characteristics of the closed-basin cores due to the very high susceptibility to precipitation and evaporation balance are beneficial for determination and evolution of late Quaternary sedimentary specification. Playa defined as an intra-continental arid zone basin with a negative water balance for over half of each year, dry for over 75% of the time, with a capillary fringe close enough to the surface such that evaporation will cause water to discharge, usually resulting in evaporites.

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Journal: 

GEOSCIENCES

Issue Info: 
  • Year: 

    2009
  • Volume: 

    19
  • Issue: 

    73
  • Pages: 

    187-177
Measures: 
  • Citations: 

    0
  • Views: 

    81164
  • Downloads: 

    31395
Abstract: 

Determining and studying collected lithic assemblages, biota remains and deposited beds (regarding to SEDIMENTOLOGY) of two rock shelters in the age of Late Pleistocene to recent interval in central Iran were the aims of this research. Mobarekeh (Qaleh Bozi) and Yekeh Chah (near Golpayegan) are two sites in which remains of consumed and hunted biota by human were checked by this research. Lithic assemblages are studied considering their sources. Mousterian lithic assemblages from Qaleh Bozi caves and rock shelters (Hassan Abad Caves) are made of silica pebbles (limestone with Nummulite or cherty beds in the age of Paleocene to Eocene time interval) that hominids had collected from the Zayandeh Rud River in the Middle Paleolithic Period. Finally it should be stated that lithic artifacts in Yekeh Chah are mostly Quartzite sandy shale (probably belong to Jurassic). Black beds (charcoal lenses) in Qaleh Bozi and Yekeh Chah caves were sampled and washed for Detemining biota remains and sedimentary components. All washed samples from two localities had remains of: burned wood (charcoal), large vertebrate mammals (mostly horse), vertebrate and micro vertebrates (fish, rodent, reptile and amphibian), egg of birds, seeds and grass. SEM photos related to hunted and consumed birds' beak and nails from Mobarekeh and Yekeh Chah con finned that the food of man in those localities could be similar. This research is first report the presence of hunter-gatherer horn inids in Central Iran (Mousterian). Lithic assemblages are collected from Separab Naein in the age of Mesolithic and from Tapeh Ashena (Chadegan) in the age of Neolithic as well.

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Journal: 

GEOSCIENCES

Issue Info: 
  • Year: 

    2016
  • Volume: 

    26
  • Issue: 

    101
  • Pages: 

    69-78
Measures: 
  • Citations: 

    0
  • Views: 

    422
  • Downloads: 

    215
Abstract: 

The elongated Elyato River catchment, covering about 52. 89 Km2 areas, is located in southwestern Fariman. To understand the grain size variation and effective factors in downstream fining, 35 samples from central axis of Longitudinal Bars have been collected and analyzed. The results indicate that the grain size decreases downstream as exponential. The lithological and geomorphological changes and faulting are effective in the slope percentage changes downstream. Based on petrographic studies, sediments on the river’ s substrate are igneous rock fragments such as gabbro and serpentine group. However, based on sedimentological studies, we show that the sediments of Longitudinal Bars are mostly poorly and very poorly sorted, near symmetrical to very positive skewness and mesokurtic and platy kurtic kurtosis. Six sedimentary facies including grain supported gravel (Gcm), matrix supported gravel (Gmm), grain supported gravel with horizontal bedding (Gh), massive sand (Sm), laminated mud (Fl) and massive mud (Fm) are recognized along the wall of the studied river. These sedimentary facies have formed in 3 architectural elements including channel (CH), Gravel bars and bed form (GB) and fine grain clastic deposits (FF). Based on sedimentary facies and architectural elements, sedimentary model for this river is proposed as gravelly braided river system.

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Issue Info: 
  • Year: 

    2018
  • Volume: 

    18
  • Issue: 

    49
  • Pages: 

    187-198
Measures: 
  • Citations: 

    0
  • Views: 

    561
  • Downloads: 

    289
Abstract: 

Paleo-climate reconstructions based on multi-proxy such as SEDIMENTOLOGY is current in climatology investigation. In this way, National Institute of Oceanography and Atmospheric Science cored 960cm from Arzhan wetland SW of Iran than we have investigated of SEDIMENTOLOGY. Primarily the core was measured on magnetic sensibility per 1cm and secondly was subsampled according to magnetic sensibility and were analyzed include TOC, CaCO3, and Grading laser and etc. Finally four samples of pace of plant were selected and have been dated in carbon 14 dating laboratory of Poznan, Poland, and calibrated trough of core based on Calib rev. 7. 1. Dating have determined that core had covered 15000 Cal. BP. According to this investigation, we obtained 5 period of climate conditions during Pleistocene to Holocene in this area. 15000-13000 Cal. BP. Late Pleistocene climate conditions were colder and wetter period that indicate end of the Ace age. 13000-11000 Cal. BP. Climate begin to warmer and dryer. 11000-9000Cal. BP. because of this period shows many fluctuations in all proxies we named this period to the period of transfer from ace age to interglacial period. 9000-7000Cal. BP there have been warm and cold conditions compare to late Holocene. 7000-Present indeed in this period radiantly modern pattern of atmospheric circulation has been performed due to all of proxies in late Holocene begin to fixed on the same pattern. So probably atmospheric circulation from meddle Holocene begin to get harmonic to present. Any way for determinate of paleo-climate in this area we need to use of multi proxy investigation in area.

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Journal: 

GEOSCIENCES

Issue Info: 
  • Year: 

    2006
  • Volume: 

    15
  • Issue: 

    58
  • Pages: 

    114-125
Measures: 
  • Citations: 

    1
  • Views: 

    1151
  • Downloads: 

    494
Abstract: 

The Kashaf-rud formation is a sequence of siliciclastic sediments outcropped in the southeast of Kopeh-dagh region. Its lithology consists of conglomerate, sandstone, limy sandstone and shale. However, Tapeh Nader area presents different lithology, comprising sandy limestone, limy sandstone and shale with belemnite, ammonite, barchiopoda, gastropada, bivalve, bryozoa, ostracoda, coral, and crinoid. The genus of these carbonate rocks are biosparite or bio oo sparite that shows coastal environments in this area, whereas, original facies of Kashaf-rud formation is detrital facies. Many evidences display that turbidity currents were efficient on the creation of these sediments, i.e., turbiditic classic sediments, massive sandstone, pebbly sandstone, and conglomerate. The most important fossil in this formation is Ammonites, of which 13 genera and 18 species were recognized and classified in two biozones (Garantiana and Parkinsoni zones).

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