رضا موسوی حرمی

In this study, a continuous wavelet transform (CWT) approach is used to decompose the gamma-ray and porosity logs into a set of wavelet coefficients at different scales. Moreover, discrete wavelet transform (DWT) was used to decompose the well logs into low-frequency components of the signal called the Approximates (A) and high-frequency components called the Details (D). In addition, this method was investigated using a case study of the Upper Sarvak Formation in Dezful embayment in southwest Iran. Moreover, various graphical visualization techniques of continuous wavelet transform results helped to understand the boundaries of the original sequences better. Also, using DWT, the maximum flooding surface was identified from each frequency analysis of petrophysical logs. There is a sharp peak in all A&D related to the maximum flooding surface (MFS), which is particularly visible in the coefficients of the fifth approximation (a5), the fifth detail (d5), the fourth detail (d4) and the third detail (d3). Moreover, sequence boundaries were best detected from the low-frequency content of the signals, especially the fifth approximation (a5). Typically, the trough of the fifth approximation corresponds to the sequence boundaries, where higher porosities have been developed in the carbonate rocks of Ilam and Upper Sarvak. Through the combination of both CWT and DWT coefficients, a more effective differentiation of stratified surfaces was achieved. Moreover, the results of this study show that the wavelet transform is a successful, fast and easy approach to identify the boundaries of the main sequence from well-logging data. Ultimatly, there is a good agreement between the results of core analysis and the results of well-logging data analysis using the wavelet transform approach.

The study of Aptian-Albian sequence in many parts of the Zagros Basin and the Arabian plate has always been limited due to the discontinuity of sediments during this period. The Tang-e Maghar, located in the Dezful Embayment, is one of the few continuous sequences of the Aptian-Albian marine sediments on the Arabian plate, the study of which provides valuable information about the paleogeological status of this period. In this study, in addition to examining the trend of changes in% TOC and% CaCO3 values through the Aptian-Albian transition sequence in order to analyze the state of the oceans, sedimentary micro-losses have also been investigated using a thin section study. In the Tang-e Maghr section, the TOC level at the base of the albino turbulence has reached 5.8%, which indicates the presence of black shale in this section. This important finding, along with the biostratigraphic data of previous studies, in addition to determining the chronostratigraphic position of this shale, has made it possible to accurately match it with other black shale horizons in other sedimentary basins. Changes in CaCO3 levels have also been recorded in different layers with different values. The most important of these fluctuations in terms of paleoecological interpretations have been at the end of Aptian and the beginning layers of Albian, which is known for a significant decrease in CaCO3 levels. This combined with fossil data from previous studies can confirm the acidic conditions of seawater at the time of Aptian-Albian sediment deposition.

In the Kopet Dagh sedimentary Basin in north east of Iran a full record of Mesozoic and Cenozoic strata is present. In the Kopet Dagh Basin, Neyzar and Kalat formations belongs to the upper Cretaceous strata. Neyzar Formation is located on the Ab-Talkh Formation and is overlain by the Kalat Formation and mainly consists of fine to medium grain sandstone in the lower part and limy shale and marl at the upper part of the section (Darvishzadeh, 1370). The main aim of the present study are to investigate on the calcareous nannofossils at the upper part of Neyzar Formation and the lower part of Kalat Formation in order to determine the exact age of the strata in Tange-Neyzar section. For determining the paleoenvironment, the calcareous nannofossils paleoecology has been investigated.

Fourteen samples from the upper part of Neyzar Formation and 6 samples from the lower part of the Kalat Formation have been studied. Systematic sampling in every mater has been done. For studying calcareous nannofossils regarding biostratigraphy and paleoecology simple smear slides (Perch-Nielsen, 1985) were prepared. For calcareous nannofossil biostratigraphy Sissingh (1977) biozonation emended by Perch-Nielsen (1985) and Burnett (1998) zonation have been applied.

From the base of the section, species such as Reinhardtites Levis, Ceratolithoides aculeus, Uniplanarius sissinghii, Eiffellithus parallelus are present. The first occurrence (FO) of Reinhardtites levis is a marker for the middle part of UC14dTP, the FO of C. aculeus indicates the boundary of UC15aTP and UC15bTP subzones, the FO of U. sissinghii marks the boundary between UC15bTP and UC15cTP, and the FO of E. parallelus shows the boundary between UC15cTP and UC15dTP subzones. From the early parts of the section, E. examine is present that its LO indicates the boundary between UC15 and UC16 biozones and is observed up to the end of the section. According to the mentioned taxa, calcareous nannofossil subzone UC15eTP with early late Campanian age was identified at the studied interval. The presence of taxa with cold water affinity like M. decussata, Prediscosphaera spp., Eiffellithus spp., A. cymbiformis and A. octoradiata and the absence of warm water taxa indicate decrease in temperature and cool greenhouse condition. Micula decussata which marks cool, oligotroph and stressful condition (Pospichal and Wise, 1990; Thibault and Gardin, 2006; Watkins and Self-Trail, 2005) is dominant at the studied interval. Prediscosphaera spp. is also abundant and is a marker of cold (Watkins and Self-Trail, 2005) and oligotroph (Friedrich et al, 2005) surface waters. The highest relative abundance of W. barnesae which is a warm and oligotroph taxa (Thierstein, 1981; Lees, 2002; Sheldon et al, 2010) is recorded at the lower part of the section, Lithraphidites carniolensis with warm and oligotrophic affinity is common is stratified photic zones (Friedrich et al, 2005) that its highest relative abundance is recorded at the lower part of the interval. Eiffellithus spp. with the highest relative abundance of E. turriseiffelii at the lower part of the section is considered as an oligotroph taxa (Friedrich et al, 2005). The highest relative abundance of A. cymbiformis with cold surface water affinity (Thierstein, 1981; Barrera, 1994; Watkins and Self-Trail, 2005) is recorded at the lower part of the section. The highest relative abundance of B. bigelowii is also recorded at the bottom of the section. In the Zagros sedimentary Basin, C. ehrenbergii is considered as cold water taxa, but a decrease in the depth is also important (Razmjooei et al, 2020).

According to the calcareous nannofossil taxa at the upper part of the Neyzar Formation and the lower part of the Kalat Formation, UC15eTP subzone equivalent with the upper part of CC22 biozone of Sissingh emended by Perch-Nielsen has been identified. Because of the week preservation of the calcareous nannofossils, U. trifidus was not recorded. Species such as E. eximius and R. anthophorus that are markers of the uppermost part UC15 and CC22 are recorded up to the top the section. Regarding these data early late Campanian age was determined for the studied interval. The dominance of cold water taxa like M. decussata, Prediscosphaera spp., Eiffellithus spp. and A. cymbiformis and the absence of warm water taxa indicate cool greenhouse condition at this time interval similar to other parts of the world.

In this study, the pollution of the Revenj River sediments with heavy elements has been studied. Revenj River catchment with an area of ​​131 Km2 is located 20 kilometers from the city of Torbat-e-Jam (northeast of Iran). To investigate the contamination of sediments with heavy elements, 15 samples of sediments were taken from the area and analyzed by ICP-MS. In order to monitor the contamination of Revenj River sediments with heavy elements, Enrichment Factor and Contamination Factor were used. Chromium with low eenrichment and iron and nickel with no enrichment have similar geochemical behavior and originate from weathering and erosion of ultramafic rock units and have caused low pollution. Arsenic and lead are low pollution and copper is moderately pollution in the area. Shemshak Formation has led to a focus on arsenic and lead pollution at the beginning of the Revenj River catchment. The passage of tributaries over the granite units and the confluence of these tributaries at the end of the catchment with the Revenj River has led to relatively severe enrichment and contamination of copper and lead in the sediments at the end of this catchment. The pollution load index shows the concentration of pollution at the beginning and end of the catchment area, which is in line with the previous indicators.

Upper Cretaceous period can be considered as the peak of diapirism movements in Zagros sedimentary basin (Bosak et al, 1998). After sedimentation of Hormoz salt series, these salts were rising up towards the surface during the Lower Paleozoic (Jahani et al, 2009).  In this study, Cenomanian-Santonian strata in Fars area that consist of Bangestan group (NE-SW trend), have been studied based on effect of local and regional diapirism on these strata.

One hundred and sixty samples from two stratigraphic sections (upper part of Kajdumi Formation, Sarvak Formation and lower part of Gurpi Formation) in Darmadan anticline (Near salt dome and far from it) have been studied. All samples shave been stained with alizarin red-s to enhance differentiation of calcite from dolomite (Dickson, 1966). In petrographic studies, skeletal and non-skeletal allochem percentages have been accounted based on Tucker (1991) and Flugel (2010). Identification of microfacies based on Embry and Clovan (1971) and clastisity index based on Carrozi (1989) have been carried out.

Eight microfacies related to the open marine, shoal, lagoon and tidal flat sedimentary environment areas have been identified:Open marine facies:MF1- Pelagic Foraminifera Glauconitic Wackestone/Packstone MF2- Bioclast Wackestone. MF3- Fine grained Bioclast Packstone MF4- Intraclast Wackestone MF5- Echinoderm and Rudist debris Packstone to Rudstone Shoal microfacies:MF6- Rudist Grainstone Lagoon microfacies:MF7- Orbitolinids Wackestone/Packstone Tidal flat microfacies:MF8- Sandy Mudstone Sedimentary environment Based on lateral and vertical facies changes, marginal carbonate shelf can be proposed as the sedimentary environment for these strata. In this case, sedimentation has happened in deep, outer shelf, middle shelf and inner shelf areas. Moving towards salt dome, facies change to shoal, lagoon and intertidal shallow facies. This can be due to diapirism movements in the area. Due to upward salt dome movement, some evaporitic clasts have been transported to the sedimentary environment (Giles and Lawton, 2002); this can be observed more in near salt dome sections. Diagenetic process in two sections In areas far from salt dome section, there are some diagenetic processes such as: micritization, cementation (equant), bioturbation and, glaconitization processes, but close to salt dome sections, we can see more diagenetic processes such as: cementation (syntaxial), physical and chemical compactions (stylolite), silicification, dolomitization and hematitization. This fact shows that there are more diagenetic processes in near salt dome sections which can be related to the diapirism movement in this area.

Based on petrographic studies, eight microfacies related to the carbonate shelf (from open marine to tidal flat) have been identified. Dolomitization, silicification and cementation (anhydrite and dolomite) processes had happened because of supersaturated fluids (high mg) in this area. Some diagenetic processes such as hematitization and physical and chemical compaction have increased once moving towards the salt dome. Comparing two sections to each other based on petrography, microfacies, diagenesis, energy index allochems, siliciclastic particles, gypsum and anhydrite cements, dolomite, etc. show us that diapirism had happened as a syn-sedimentation and post-sedimentation process.

The Qatar-Cowbandi arc is a giant regional anticline with northeast- southwest direction, runs through the Qatar peninsula, extends northeastward through the Iranian sector of the Persian Gulf. The arc in the Iranian part is subject of the study meditation. In this paper the interpretation of 2D seismic in the interval of top of Laffan to top of Jahrum formations, allows the regional research of the arc in the study area. Seismic interpretation in both horizons have distinct indications for existing a platform in the area with northwest- southeast direction, which smoothly dipping toward northeast, with some highs resulted from salt diapirs activity. According to isopach map provided for sedimentary sequence of Ilam-Jahrum formations, which was prepared based on 2D seismic data, the sediments thickness decreases in the platform area. The platform is interpreted as crest of arc, on which low rate of sediment precipitation occurred due to low accommodation space, resulted from the arc uplifting activity. Therefore, the arc and also salt diapers, should be considered as regional important factor in sequence stratigraphy study for the precipitated sediments.

To assess surface and groundwater quality in Shahid Hashemi Nezhad Gas Refinery region and effluent wastewaters from this industrial unit, 18 water and 5 wastewater samples were studied. Major anions and cations concentration ,pH, temperature, EC and TDS were measured in water and wastewater samples. Most of the water and wastewater samples were classified as brackish and saline water based on TDS content. Calculation of sodium hazard indices of irrigation water showed that only 30% of the water samples were in excellent range according to SAR, and the others have good, fair and poor quality. Among the wastewater samples only one sample showed excellent quality according to this parameter. Majority of water and wastewater samples had fair and unfavorable quality based on %Na and KR. Based on SAR and EC, only one wastewater sample had fair quality. RCS and RSCB showed suitable quality for the water and wastewater resources. Gibbs diagram, chloroalkaline index and binary diagrams showed evaporation, normal ion exchange and evaporative mineral dissolution (halite, gypsum and anhydrite) as effective factors on chemical composition of water resources.

In this research, petrographic and geochemical (major and trace elements) characteristics of siliciclastic rocks of the Mozduran Formation in the eastern Kopet-Dagh Basin have been carried out in order to reveal their provenance such as source area paleoweathering, parent rock composition and tectonic setting. Mozduran Formation is mainly composed of limestone and dolomite, with minor amounts of siliciclastic rocks and evaporites. Siliciclastics rocks (sandstone and shale) of Mozduran Formation are mainly present in the easternmost parts of the Kopet-Dagh Basin. Four stratigraphic sections of Mozduran Formation, namely Kole-Malekabad, Kale-Karab, Deraz-Ab and Karizak, were measured and sampled in the SE of the basin. Petrographic investigation showed that the sandstones are mostly classifies as litharenite and feldspathic litharenite. Geochemical data revealed that CIA values of Mozduran siliciclastic rocks confirm a medium weathering that can be due to semi-arid climatic condition in the source area. Felsic composition of parent rocks and quatzolithic petrofacies of Mozduran Formation sandstones and their constituents such as Qp, Qm, Ls, Lm and F, together with paleocurrent analysis show that these siliciclastic sediments may have derived from uplifted and trusted belt of sedimentary or sedimentary- metamorphic rocks of south Mashhad and metamorphic rocks of north Fariman region. Petrographic and geochemical analyses suggest that these sediments deposited in a continental rifting system.

The cause of fining grain size toward downstream is a subject for decades, because grain size variation can be effected by sediment transport, bed roughness and hydraulic sorting (Frings et al., 2010: 831). Two processes have been considered to explain downstream grain size decreases in gravel-bed rivers: (1) abrasion of single grains that reduce their size and (2) hydraulic sorting or selective transport due to differential transport (Moussavi-Harami et al., 2004: 474). The size of gravel bed material typically decreases with increasing distance downstream, can be attributed to a combination of abrasion during transport, abrasion of gravel in place, weathering, selective entrainment and/or enhanced transport of finer sediment sizes and tributary effect (Pizzuto, 1995: 753). The textural characteristic of sediments is widely affected by several factors including the source area, climate, distance and the sediment transport energy in sedimentary environments (Kumar Maity and Maiti, 2016: 1128). This paper examines the downstream fining and factors that control the rate of fining in the Rayen River in southeast Kerman, which can be used as a model for interpretation of continental silici clastic rocks in the geological record. There are three main aims in this study including textural variation toward downstream, to identify a model for downstream fining and recognize sedimentary facies in the Rayen River.
During the field study, 42 samples were collected from the main channel of the river and the location of the samples were recorded by GPS. The collected sample transferred to laboratory and after drying, dry sieves with 0.5Ф intervals (from -5.5to 4Ф) used for analysis and then the weight of sediment on each sieve was weighted by a scale and then classified in to different categories by the size and using Excel program for calculation of different parameters. Then 10 thin sections from sediments on the sieve with the size 1 phi (0.5mm) prepared and examined for the composition of sediments and abrasion. The textural parameters of sediments, including mean, median, sorting, skweness and kurtosis, were measured using graphic comprehensive method of Folk (1980). The Rayen River is located in Kerman Province and about 14 km southwest of Rayen city. This study area is a part of Hezar volcanic rocks of the Urumieh- Dokhtar magmatic assemblage in south Kerman that show the latest volcano phase of the Eocene in this area and is composed of lava, pyroclastic and siliciclastic sediments. The lava consists of basaltic- andesite, andesitic- basalt and basalt. The pyroclastic deposits are volcanic breccia, volcanic sandstone and the sedimentary rocks including limestone, siltstone and sandstone. These rocks probably resulted from old compound volcanos with successive eruptions (Eocene) that had periodically activity and the eruptions were very explosive (Ahmadipor and Maleki, 2009; 47).
After analysis of sediments and calculation of the percentage of mud, sand and gravel, sediments are classified according to Folk (1980) classification. Measurement of average particle size show that most of this river sediments are sandy gravel and gravelly sand. According to triangular diagrams of Sneed and Folk (1958), most of particles are in the range of bladed and compact bladed. Due to composition of sediments and initial form, based on the andesitic origin of sediments, bladed and compact bladed are observed even in the downstream of the basin. Based on thin sections study, the river sediments formed mainly from volcanic rock fragments, containing minerals such as pyroxene, amphibole, olivine, plagioclase, opaque and quartz. Sedimentological studies along the main channel of this catchment area show that the process of changing the grain size toward downstream follows the exponential pattern decrease. The causes of fining toward downstream in the Rayen River include: •Geomorphological factors such as: decreases in elevation and gradient toward downstream.
•Sedimentological factors including: abrasion and hydraulic sorting.
The most important factor on the rate of abrasion is, composition, size and initial form of particle (Bertoldi et al., 2010; 348). Accordingly, on the upstream parts of the Rayen River, the size of particle is larger and is more angular, and moving downward, the particle is finer and is more rounded. Plotted data of mean and median, show that particle size from upstream toward downstream of the Rayen River and varies from 0.357 to 14.928 and 0.267 to 22.627 mm respectively. Decrease median and mean from upstream toward downstream of river (R2=0.806, 0.858), indicate that the rate of coarse grain in the range of gravel decreased while the finer grain in the range of sand size increased. Calculations of statistical parameters show that the sediments of the catchment area are poorly and very poorly sorted (from 1.64 to 2.63phi) with coarse skewned to strongly fine skewned (from -0.31 to 0.52) and mesokurtic to platykurtic (from 0.007 to 1.318).
Study of sedimentary facies in this river indicate that 3 different type of lithofacies including gravel (Gmm, Gmc, Gh, Gp, Gmg), sandy (Sm) and Mud facies (Fl) are present. These lithofacies have formed in four architectural elements including Channel (CH), Gravity flow deposits (SG), Gravel bars and Bed forms (GB) and Fine grains clastic deposits (FF).
Two process have been considered to describe the decrease of grain size toward downstream in the Rayen River with gravel bed. Hydraulic sorting, where the smaller grains transported faster than coarse grains, and abrasion, where individual grains based on their composition decreased toward downstream, are responsible for grain size decreases. Based on the result, Rayen catchment area is braided river with sandy gravel bed.

The Asmari Formation in Gachsaran oil field has a low lithological diversity and including of limestone in the lower parts and dolostone in the upper parts of the reservoir. The goal of this study is determination of facies, depositional environment, diagenetic processes and their effect on the reservoir quality of this formation. Microscopic studies of 478 thin sections of cores led to the identification of 11 microfacies belong to 3 facies belts including inner (tidal flat, lagoon, shoal), middle and outer ramps. This study also revealed diagenetic processes including micritization, bioturbation, neomorphism, compaction, dissolution, cementation and replacement. In order to investigation of reservoir characterization, the effects of diagenetic processes and sedimentology used on the distribution of porosity and permeability. Based on the results, dolostones with intercrystaline-vuggy porosity, wackeston/dolowackestone with vuggy-channel porosity and Porous grain-dominated Packstone are the best reservoir facies comparsion with other facies in the Gachsaran oil field. Key words: Asmari Formation, Gachsaran Oil Field, depositional environment, diagenesis, Reservoir quality.

The Koppeh- Dagh Basin in the northeast Iran formed after closure of the Paleotethys in the south of Turan plate. Kashafrud Formation in the Navia Section (west of Bojnourd) with a thickness of 749 m is composed of silici-clastic rocks (conglomerate, sandstone and shale). In order to interpret provenance of this formation in the study section, 12 shale samples have been geochemically analyzed. ­The samples are rich in quartz and clay minerals, with respect to (UCC) depletion in Na2O, CaO, MgO, Cu, Nb and Sr and enrichment in Ni, Co, V, Y and U.­ Plotting TiO2 versus Al2O3, Zr versus TiO2, as well as ternary diagram (SiO2/20), (k2O Na2O), (MgO TiO2 FeO) and diagram Al2O3, (Cao Na2O K2O), (FeO MgO) suggest that the original source of this formation was probably from intermediate igneous rocks. Calculated PIA and CIA indicate high chemical weathering and semi- humid climatic condition in the source area. Prepared discrimation diagram using the major oxides (SiO2 versus K2O/Na2O and ternary diagrams SiO2/20, Na2O K2O, TiO2 MgO Fe2O3), shows that the shales of this formation were plotted in the passive continental margin. Paleogeographic reconstruction for this formation, during the Middle Jurassic shows that sedimentation of this formation is mainly controlled by intracontinental subsiding basin and the source of these sediments was from the southeast of the Kopph-Dagh Basin.

Elemental sulfur is byproduct of natural gas refining which during this process, H2S is removed from sour gas and after changes to solid sulfur, it is stored in large block forms. Continuous precipitation of sulfur and its oxidation causes soil acidification and as a result, nutrient cations such as Ca2, Mg2, Na and K will leach from the soil profile. Also, sulfate accumulation led to soil acidification and accelerates the silicates weathering in upper layer of the soil profile. Accumulation of water soluble sulfate in the soil and increase the nutrient cations leaching from the soil depend on sulfate resistance rate. Also, addition of sulfur to the soil for a long time can cause calcium sulfate formation that will cause problems such as increase in soil salinity. Shahid Hashemi Nezhad gas refinery is located about 35 km south of Sarakhs city and about165 km east north of Mashhad. In addition to exploiting, refining and producing 50 × 106 m3.day-1 natural gas, recovered sulfur with %99/9 purity and 2000 tons per day production capacity is one of the byproducts of this gas complex.
22 soil samples were collected from surface soil in Shahid Hashemi Nezhad gas refinery (3 samples) and nearby areas (19 samples) (Fig.1). Soil extracts pH was measured in equilibrium with pure water and with KCl 1M solution in 1:2.5 soil solution ratio. EC of the soil samples was measured in different soil water ratios to obtain the EC 1:1 (Fig.2). Total sulfate content was measured by gravimetry method at geochemistry laboratory of Faculty of Sciences at Ferdowsi University of Mashhad. To get the digestion extract, a mixture of 2 ml concentrated HF, 5 ml HCl and 8 ml HNO3was added to 0.5 gr soil in a teflon vessel, then heated for 60 min at 170° C. After cooling, the solution was evaporated at 130 °C to dry it. Then, the dried salt was dissolved in a mixture of 2 ml HNO3 and 2 ml HCl and diluted with deionized water up to 25 ml. Ca2 and Mg2犉筬쇪 measured through titration of the soil extract with EDTA 0.01 N and in EBT reagent at the first stage, and titration of the soil extract by EDTA 0.01 N and in Moroxide reagent at the second stage. Na and K contents were determined using AAS method at geochemistry laboratory at Ferdowsi university of Mashhad after extraction with CaCl2 0.01 M.
Based on EC values, 77% of the soil samples were non-saline (EC Salinity is the major factor affecting decrease of the samples quality for agriculture. Exposed formations in the area with highly soluble rocks causes to increase the soluble salts in the soil. The second factor is high temperature and low precipitation that led to increase the evaporation from the soil surface and accumulation of salts on the soil. Recovered sulfur from natural gas processing can reduce the soil pH and increases the soluble salts to some extent, especially in the inside refinery samples, and then decreases the soil quality for agricultural purposes. Except for one, all studied samples were classified as non-saline and non-sodic soils. Furthermore, the samples were classified in two classes of flocculated soils and potentially dispersive soils based on SAR and EC. ESP index indicates that there is no serious problem regarding sodium concentration in the soils. The pH values indicate that the samples were almost alkaline soils except for the samples inside the site, which are slightly acidic. Acidity of those few samples are attributed to the sulfur released from gas refinery process and its effect on the soil pH.

The Aitamir Formation (Albian-Cenomanian) composed of siliciclastic rocks and several carbonate horizons. In order to study depositional environment and sequence stratigraghy, two stratigraghic sections studied in east Koppeht Dagh basin near the Baghak and Shurijeh villages. Field and petrograghic studies led to siliciclastic and carbonate facies that deposited in lagoon, barrier, shoreface and open marine environments. Sequence stratigraghy analysis led to identification of three depositional sequences in both sections. Comparision of interpreted sea level curves at studied area with Albian-Cenomanian global curve shows similarities and differences that can be relatedto tectonic setting and sedimentation rate.

Aeolian deposits are important palaeoclimate archives, partly because they are direct records of past atmospheric circulation (An et al. 2012). Distinguishing aeolian signature from lacustrine sediments is important for understanding the frequency and timing of palaeostorms. Efforts have been invested on deciphering aeolian records from lacustrine sediments in the United States (Dean 1997; Parris et al. 2010), Greenland (Mayewski et al. 2004), New Zealand )McGowan et al. 1996( and Japan )Xiao et al. 1997) providing a continuous record of Holocene aeolian activity.
Sistan Basin is a remarkable environment to study Aeolian activity changes in eastern Iran – southwestern Afghanistan. The area is one of the driest regions in the world whose sparse water resources and fragile ecosystems are very sensitive to climate change. In moist periods, fluviolacustrine and palustrine conditions are dominant while in dry periods, aeolian activities prevail. Hence, variations of aeolian deposits in sedimentary successions could be a useful tool to evaluate palaeoenvironmental conditions over the Sistan Basin during the Holocene.
Material & The closed depression of Sistan, lying on the Iran-Afghanistan border, contains four shallow basins (mean water surface at about 471m asl) that receive the discharge of Hirmand River. Sistan is located whitin the Asian part of the desert belt of the temperate subtropical zone of northern hemisphere, with a semi-desert climate (Whitney 2007). In late spring, throughout summer and early autumn the Sistan basin is dominated by the northerly “wind of 120 days”. The winds are related to the north–south pressure gradient between a persistent cold high-pressure system over the high mountains of the Hindu Kush in northern Afghanistan and a summertime thermal low-pressure system common over the desert lands of eastern Iran and western Afghanistan as a result of sustained surface warming (Alizadeh-Choobari et al 2014).
Two cores of H1 and H2 (6.2m and 6.8m long) were retrieved using a Cobra vibra-corer in west of Kuh-i Khawjeh in the dry lake bed Hamoun-e Hirmand in the Sistan Basin. Magnetic susceptibility (MS) determination (using a MS2C Bartington magnetic susceptibility meter), analyzing features of grain-size frequency curves (using a FRITSCH laser particle sizer) and petrography were conducted on sediment samples.
A bulk sample was selected from the lower half of the core H1 for radiocarbon dating. The calibrated date suggests late-glacial age for lower parts of the core H1 (13.5 ka).
Discussion of Results & The core lithology generally consists of clayey silt, silt and sandy silt layers. Based on basic sedimentological data, MS and sediment color we have recognized three main facies, A (lateglacial - early Holocene), B (early- mid Holocene) and C (late Holocene).
Since the late-glacial, the climatic regime of interior west Asia has been under the influence of various atmospheric circulation patterns and intensities (Fleitmann et al. 2007). High pressure cells of the Siberian Anti-cyclone (Siberian High: SH) from the north, low pressure cells belonging to the Indian summer monsoon (ISM) from the south, and mid latitude westerlies (MLW) governed the regional climate during thid period.
Data revealed that during the lateglacial - early Holocene, dominance of low pressure system of ISM on Sistan Basin and the western Hindu Kush provided a moist environment with less wind action. As shown by primary modal peak of grain-size distribution curves (20-30 µm), massive clayey silts with low MS (4.2 - 5.2 ×10-4 SI) and abundant plant remains, charophytes and carbonate shells in facies A are deposited in a highly productive lake with no signs of wind action. This period is also characterized by weakening MLW as well as elevated sea surface temperature in Atlantic Ocean and Arabian Sea. In addition, this humid period in the Sistan Basin is concurrent with the early Holocene long-term weakening of SH, inferred from increases in concentration of Kþ in GISP2 ice core (Mayewski et al. 2004) causing dramatic decrease in north-south pressure gradient between the Hindu Kush Mountains in northern Afghanistan and the desert lands of the Sistan Basin. High solar irradiance and weakening and northward migration of territory influenced by the SH also pushed the ISM domain northward (Mayewski et al. 2004) affecting Sistan catchment basin.
During the early- mid Holocene gradual weakening ISM (Sirocko et al. 1993) in addition to strengthening SH and MLW (Bradbury et al. 1993) caused dominance of severe wind storms in Sistan, as shown by modal peak more than 100 µm in facies B. During the mid-late Holocene, episodic high aeolian inputs in the basin by high energy dust storms comparable with the present day “winds of 120 days” are evident. Traces of palaeostorms during this time is evidenced by high oscillations of MS and presence of some sand-bearing lacustrine sequences in both cores. During this period, southward migration of ITCZ led to weakening of the ISM (Fleitmann et al. 2007), and consequently drought periods in Sistan Basin and semi-arid conditions over NW Himalaya (Dortch et al. 2013). Establishment of a high pressure gradient between the Sistan depression and the high Hindu Kush Mountains caused the occurrence of severe and frequent dust storms over the area.
Our results suggest that the late Holocene in the Sistan Basin (facies C3) was characterized by frequent changes in MLW and SH activity. Palaeoclimatic records show since the mid Holocene to the present time, the climate of Sistan and its catchment area more or less oscillated around a steady state comparable with modern situations (Hamzeh et al. 2016). During this time, the hydroclimatic regime and Aeolian activity of the Sistan Basin and NW Himalaya have been mostly governed by MLW-associated precipitation. Periods of prolonged droughts are indicated in proxy records of NW Iran such Lake Neor (Sharifi et al. 2015), presumably consistent with high MS values in our record. It is possible that weakening of ISM, along with distal influences of the MLW during the late Holocene exposed the Lake Hamoun basin to frequent droughts. Frequent lake level fluctuations show unstable climate of the Sistan Basin during mid to late Holocene with frequent wind storms.

The Fahliyan Formation of Khami Group is hosting important hydrocarbon reserves in Iran and also is a main reservoir rock in the Abadan Plain oil fields which is Neocomian in age. In the studied wells its thickness is about 440 meters. In the Abadan Plain, the Fahliyan Formation transitionally overlies the argillaceous limestone of the Garau Formation and its upper boundary changes into marl and argillaceous limestone of the Gadvan Formation. According to thin sections examinations prepared from cuttings and cores plus electrofacies analysis 11 microfacies and 2 lithofacies are recognized. This formation consists of two carbonate and mixed carbonate-siliciclastic (mixed zone) members. The Lower Fahliyan was deposited in carbonate ramp environment while, the Upper Fahliyan was deposited in a mixed carbonate–siliciclastic environment. To determine electrofacies, the rock types were modeled with using MRGC method. Best correlation between petrographical and electrofacies is 12 cluster model (in MRGC method). These results suggest that the electrofacies model is in agreement with heterogenetic rock type such as mixed carbonate–siliciclastic environment observed in petrography. Also, in homogenous rock type such as carbonate ramp environment electherofacies can’t completely determine geological facies. Based on petrographical and electrofacies this formation is composed of three third order sequences with type sb2 sequence boundaries. But, the third sequence in mixed carbonate–siliciclastic zone is terminated with sb1 sequence boundary just below the Gadvan Formation.

Introduction The siliciclastic sediments of Kashafrud Formation (Bajocian–Bathonian) in the Kopet-Dagh Basin (Madani, 1977; Afshar-Harb, 1979) are composed of conglomerate, sandstone and shale. It is reported that these sediments were mostly deposited in deep water environment in the eastern Kopet-Dagh basin (Poursoltani et al., 2007; Taheri et al 2009; Poursoltani and Gibling, 2011). The study area is located in west of Bojnurd in the western parts of the basin with a thickness of about 749 m and consists of three units. It covers unconformably the limestone of Triassic Elika Formation and overlaid by carbonate sediments of Chamanbid Formation. The purpose of this research is to interpret depositional environment and sequence stratigraphic analysis of the Kashafrud Formation in order to understand the paleogeography of Middle Jurassic time.
Methods This research is based on field observations of one measured stratigraphic section in Navia area and petrographic studies of 69 samples. Lithofacies are classified, using Miall codes (2000, 2006) and thin sections are used for determination of composition and texture of coarse grain rocks. 10 shale samples have also washed for micro- paleontological study and three samples, including shale and sandstone, have studied with SEM and EDX by LEO-1450 V model in Central Laboratory of Ferdowsi University of Mashhad. We also measured 44 directional structures azimuths for paleocurrent analysis.
Results Based on field studies, three lithofacies are recognized in the study area as follow.
Conglomerate lithofacies are observed in the basal part of the studied section with 7 m thickness and is composed of Gcm, Gt and Gmm lithofacies. They are mostly grain-supported with graded bedded, poorly sorted with rounded pebbles, low sandy matrix and trough cross-beds (Gt). Gmm is identified by increases in sandy matrix, moderate sorting and quartz pebbles content.
Sandstone lithofacies consist of St, Sp, Sm, Se, Sl, Sr, Sh, Sm and St lithofacies. St is the most abundance sandstone lithofacies in unit 1. In this lithofacies grain size decreases upward and changes to thin-bedded and fine grain sandstones. Sp with planar cross bedding has Ophiomorpha trace fossil in unit 2. It has low angle and planar cross bedding that vertically changes to Sr lithofacies. Sr (Rippled lamination and layered sandstone) is present in both units 1 and 2 but it has Palaeophycus and Thalassinoides trace fossils in second unit. Sh lithofacies is recognized by parallel or horizontal bedding and lamination. This lithofacies is less abundant in unit 1 and interbeded with mud rocks lithofacies, while in unit 2 it seen with Sl lithofacies. Sl (Low angle cross-bedded sandstone) and is the most abundant lithofacies in unit 2 and mostly fine grain and associated with Sh and Sr. Se (Erosional scours) is mostly observed at the base of sandstones and associated with Sp and Sm.
The Kashafrud sandstones are mostly sublitharenite and minor amounts of litharenite with mineralogically supermature and textural submature.
Mud rock lithofacies consist of laminated (Fl) and massive (Fm) fine grain rocks. The Fl lithofacies is mainly composed of silt-size grains with Palaeophycus, Planolites and Rhizocorallium trace fossils in unit 3.
Discussion Kashafrud Formation is interpreted to be deposited in fluvial and deltaic environments. Fluvial environmentis supported by fining upward cycles, abundance of sandstone, well-rounded grains, trough cross-bedded and Plant remnants in red shale. They have mostly sublitharenite composition. Calculated chemical weathering index indicated that the rocks at the source area have been highly affected by high weathering condition that can be related to warm and semi-humid climatic conditions (Sarbaz et al., 1395, in press). Paleocurrent analysis also revealed that the probable source of these sediments can be located in south of the Kopet-Dagh basin.
Deltaic sediments are composed of proximal and distal delta front as well as prodelta. Proximal deposits consist of several coarsening upward cycles including shale and fine to coarse grain sandstones with a thickness of about 7 m. Dominant sedimentary structures are horizontal and low angle cross-lamination, wavy ripple cross-lamination, massive beds, hummocky and trough cross-beds as well as plant fragments. These evidences show that sediments may have been affected by interaction of long-shore waves as well as storm events (e.g. Edwards et al., 2005; Hampson, 2010).
Distal delta front form the main parts of sediments including fine-grain black to olive green shale and siltstone with fine sandstones interbeds. Major lithofacies are Fl and Fm with Palaeophycus, Planolites and Rhizocorallium trace fossils. These intervals may have been deposited below wave base under low energy conditions (Einsele 2000; Alvan and Eynatten, 2014).
Prodelta sediments are mostly composed of clayey and silty shale. Based on vertical variations of these sediments to silty and fine to very fine grained sandstones of distal delta front, they may have been deposited in low energy and probably more reduction conditions (Hoir et al., 2002). The study of small foraminifera of deltaic shale led to identification of 14 different species of 12 genera. The community of these microfossils, which is reported for the first time, show that deposition may have taken place in the shallow water near shore environment within about 50m depth (e.g. Murray, 1991).
Sequence stratigraphy Kashafrud Formation in this section is composed of two depositional sequence (DS1 and DS2). The lower boundary of the first sequence (DS1), based on angular unconformity (above Triassic limestone of Elika Formation) and fluvial conglomerate deposits, is type I (SB1). The upper boundary of DS1 is SB2 and is located in proximal delta front deposits with no subaerial exposure evidences. The thickness of the first sequence is about 400 m and consists of LST, TST and HST. The LST is composed of continental sediments (137 m) that is covered by transgressive surface. This surface reveals by massive shale (50 m) of distal delta fronts and maximum flooding surface is located in the upper part of these deposits. HST (215 m) is composed of 12 shallowing and coarsening parasequences. DS2 with thickness of about 349 m is separated from DS1with sequence boundary type 2. This depositional sequence is only composed of TST with Fm and Fl lithofacies that transitionally changes to deeper water black shale that follows by marl and fine grain carbonate sediments of the Chaman-Bid Formation. Therefore, the maximum flooding surface is probably located within the Chaman-Bid Formation. Interpreted sea level fluctuation curve of the study area can be related to regional geological history and sometimes can be relatively correlated with global sea level curve (Haq et al, 1987)

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.

Carbonate deposits of members 1 to 2 of the Mila Group (Middle Cambrian) in Central Alborz that call the Deh-Sufiyan Formation in this research, were studied in Shahmirzad, Tueh-Darvar, Mila-Kuh and Deh-Molla sections. The Unit 2 of Deh-Sufiyan Formatrion in Central Alborz of Northern Iran consists mainly of shallow marine carbonates and contains a variety of limestone conglomerates. Limestone conglomerate is an important component of Unit 2 of Deh-Sufiyan Formatrion, but its origins remain enigmatic. These limestone conglomerates have a diverse set of characteristics that range clast to matrix supported with scattered flat pebbles. These conglomerates are largely comprised of oligomictic, rounded lime–mudstone clasts of various sizes and shape (equant, oval, discoidal, tabular, and irregular). According to composition and characteristic sedimentary structures and fabric, limestone conglomerates in the Unit 2 of Deh-Sufiyan Formatrion consist of: (1) Intraformational limestone conglomerate beds were formed by depositional processes (2) Limestone pseudoconglomerate beds were produced by diagenetic processes. The common characteristics of the Unit 2 of Deh-Sufiyan Formatrion pseudoconglomerates, such as oligomictic lithology of lime–mudstone clasts, mosaic fabric, disorganized/edgewise fabric, variable and gradational fabric, transitions adjacent or underlying facies and the complete lack of depositional structures, are typical of pseudoconglomerates formed by early diagenetic sediment deformation under shallow burial conditions. These characteristics are different those of intraformational limestone conglomerate showing primary depositional features such as normal or inverse grading, internal stratification, (hummocky) cross-stratification and sharp erosional bases. Diagenetic conglomerates in ribbon rocks resulted soft-sediment deformation of ribbon rocks during early diagenesis. In contrast, the dimension and thickness, sizes of the clasts, clast-rich beds, size ingredient of matrix, tendency to amalgamate with amalgamation scours within depositional conglomerates suggest that high energy and strong erosion above storm wave base was responsible for the disintegration of the carbonate material.

Marusk Catchment with an area of 131.87 square kilometers is located in the Northwest of Neyshabur. Baghi River as one of the main tributary of this catchment has been studied with a length of about20.1km.For sedimentological studies a total of 32 sediment samples taken from the active mid-channel of the river that after drying, the granulometry has been analyzed by dry sieving method. After the sample sieving, statistical parameters (median, mean, sorting, skewness and kurtosis) were calculated.3 sedimentary discontinuities have been detected in the sediments of the river. First and second discontinuity is due to input of sediments from the alluvial fan and tributary into the main channel, respectively, and third discontinuity is due to changes in lithology. To determine the percentage of erosion in the formations in this region and determine the amount of sediment yield in each of formations, Abrasion Los Angeles Test is done. Based on this method, Dalichai Formation with according to its lithology and also a great expansion in the region is main formation for sediment yield in this area. In the study area, coarse-grained sedimentary facies (Gmg, Gci), medium-grained sedimentary facies (Sm) and fine-grained sedimentary facies (Fl) were identified. According to sedimentary facies, the architectural elements of SG and FF have been identified. Sedimentary models proposed for this river are including braided gravelly river with sediment gravity flow and shallow braided river with gravel-bed load.

Asmari Formation (Oligocene-Miocene) is one of the most important reservoir in the Aghajari oil field in the Dezful Embayment in south west of Iran which is composed of limestone, dolomite and sandstone units. The purpose of this study is to identify, differentiate and interpret the diagenetic processes and their impact on the reservoir quality of the Asmari Formation in wells 64, 30 and 149 of Aghajari oil field. The most important diagenetic processes that affected the Asmari Formation include dissolution, compaction, fracturing, dolomitization, cementation and anhydritization. Processes such as dissolution (by creating vuggy and moldic porosity), fracturing and dolomitization increase the reservoir quality while and processes such as anhydritization, compaction and cementation reduced the reservoir quality in zone of 3 and 4. Also one of the reasons for increasing the reservoir quality of Asmari Formation is the present of sandstone units in the Dezful Embayment. These increases in reservoir quality can be related to sorting and rounding of grain size, geometry and distribution of sandstone in this oil field. These processes led to creation of the best reservoir quality in quartzarenite and limy sandstones facies. Finally, zone 3 has a better reservoir quality than zone 4 that it is due to impact of diagenetic processes as well as increases sandstones thickness.

Farub Roman River with a length of about 19 km in the Northeast Neyshabur is a perennial river. To determine the sedimentary parameters in this river, 55 samples were taken from the main channel of this river and then granulumetry analysis and statistical parameters were calculated. The mean sorting of sediments is1.609phi (Poorly sorted) and skewness is 0.393 (Strongly fine skewed) and Kurtosis is 0.965 (Mesokurtic). This river is of braided type with load gravel bed. In this river, four sedimentary discontinuities and five sedimentary links are detected. Grain form of the river is in the range of very bladed, and major of deposits are in gravel range. Facies that could be identified in this river are: Gci (grain supported gravel), Gmm (matrix supported Gravel), Gmg (graded and matrix supported Gravel), Gh (grain supported gravel with horizontal bedding)) for gravelly facies, sand with horizontal bedding (Sh) for sandy facies and massive mud (Fm) for muddy facies. The facies formed in these structural elements are such as Channel (CH), Gravity flow deposits (SG), Gravel bars and Bed forms (GB) and Fine grain clastic deposits (FF). Based on the results, sedimentary model for Farub Ruman River is of braded type with loaded gravel bed.

Silisiclastic deposits of Member 5 of the Mila Group in Central Alborz that call Lashkarak Formation in this research, were studied in Shahmirzad, Tueh-Darvar, and Deh-Molla sections in order to reconstruct their depositional environments and sequence stratigraphic framework. The integration of sedimentological and ichnological characteristics of estuary and open marine deposits of the Lashkarak Formation has led to more reliable determinations of the relative degree of influence imposed by river influx, waves, and storms on the coastal regime. Relying on the facies characteristics and stratal geometries, the siliciclastic successions of the Lashkarak Formation are divided into two facies associationswave-dominated shoreface-offshore complex andwave-influenced estuary. High resolution sequence stratigraphic data have been used to subdivide the strata into two third-order sequence sets contains five fourth-order parasequence sets. Lowstand fluvial deposits of the first stage of the valley-system fill occur in sequence 1. These fluvial deposits are overlain by coastal-plain and wave-dominated estuarine strata during TST and HST. A drastic change to open-marine conditions is marked by a marine flooding surface during HST. Open-marine strata are dominatly lower-shoreface and offshore-transition deposits. Although the interpreted depositional systems and stratigraphic architecture of sequence 1 of the Lashkarak Formation resemble transgressive incised-valley-fill successions, the greater thickness and larger size of the Lashkarak valleys suggest valley development during a relative sea-level fall. The sequences 2 of the lashkarek Formation is composed of transgressive and highstand systems tract couplets interpreted as reflecting eustatic sea-level changes and the continuous creation of accommodation during eustatic sea-level changes. These sequences indicate the transgressive and regressive cycles coeval with eustatic sea-level fluctuations during Ordovician.

Introduction Barchan dunes and nebkhas are great geomorphologic phenomena of desert areas in south of Damghan. The purpose of this study is to analyze the sedimentology of sand dunes and nebkha deposits in the Haj Aligholi Desert. More than two-thirds of the Iran's area is arid and semi-arid land. The diversity of flora is limited in these areas because of low humidity. This causes the wind to easily effect on the surface of these lands and carries the sand size and finer grains and deposited in another place. Barchan sand dunes are the most abundant type of sand dunes in the Haj Aligholi Desert. Dispersed vegetation plays an important role in sediment transport and nebkhas formation in this area. Nebkhas or sand dunes are formed usually in hot and humid and semi-arid regions and widespread where the sand can be trapped by vegetation. The study area is located about 35km south of Damghan in 54°, 10' to 54°, 30' E longitude and 35°, 45' to 36°, 00' N latitude. Material and Methods 27 and 15 samples were collected respectively from the sand dunes and nebkhas to determine the sedimentary parameters. Grain size analysis was carried out using dry sieve with a set of 0.5 phi screens for measurement of statistical parameters (mean, median, sorting, skewness and kurtosis). For morphometric investigation the parameters of sand dunes (lee side, stoss side and crest) and nebkhas (long axis, short axis and height length) were measured. Result and Discussion The mean diameter of the grain size, the average of sorting, skewness and kurtosis in the sand dunes are about 2.435 phi (fine sand), 0.530 phi (moderately well sorted), -0.268 (coarse skewed) and 1.054 (mesokurtic), respectively. The mean diameter of the grain size, sorting, skewness and kurtosis in the nebkhas are about 2.800 phi (fine sand), 0.540 phi (moderately well sorted), -0.070 (near symmetrical) and 1.640 (very leptokurtic), respectively. The comparison between the index of kurtosis and sorting show that with increasing of the grain's kurtosis, the grain's sorting increased. After doing regression for each of the independent variables versus the dependent variable to height was calculated. The results show that the attribution of the stoss side and the crest show the best correlation. Therefore, with stoss side and crest components, we can calculate the height of sand dunes from the high-resolution images satellite. To compare the relationship between the longaxis's length and short axis's length, as well as the long axis's length and height of the nebkhas obtained the regression equation in the study area. The results show that this both variable are suitable for measured of long axis in the nebkhas. In this study, both types of nebkhas (active and passive) were identified that cause of the deactivation of them is dropping in the level of groundwater, which its witness is embayment and cracking on the surface of the ground. Due to the prevailing of northwest wind seems to be the accumulation of sediments at this area is closely related to the groundwater table and soil moisture of this region. Conclusion The average of sorting calculated for sediments of sand dunes and nebkhas was moderately well sorted showing two source for sediments (bimodal) and it cause to decrease the amount of sorting. The average of skewness of sand grains skewed to the coarse grains. We can found type movement of sediments that it is saltation. Northwest wind that blowing in study area controlled sand dunes type and position and cause of this claim is morphology and situation of sand dunes. The results of regression revealed that the attribution of the stoss side and the Crest in sand dunes and and also in nebkha dunes the attribution of the short axis and height show the best correlation. In the study area both nebkha (active and passive) found which phenomena annihilator of nebkha is falling groundwater level that it's increasing the desertification.