Quaternary Journal of Iran

Abstract Vegetation is very sensitive to climate change and is an important factor for identifying the changes of climate and environment. In 12000 to 6000 years ago there was extreme climatic conditions in the southwest Asia with hotter and longer summers than the current conditions. As a result of such climatic conditions, many shallow lakes and seasonal rivers have been disappeared and vegetation altered. Plants that were more adapted to environmental conditions and dry seasons like annual plants includes (peas, lentils, wheat ) by the  changes in legume and shape of the grain, completed their annual life cycle. Studies have shown that the climate has changed between cold and dry conditions during glacial and hot and humid periods in interglacial in north and west of Iran. The lake sediments and paleo sol layers in loess deposits indicate there was an increase humidity during period between the last interglacial and pre end glacial period (Kehl, 2009). The Palynological results of paleo ecological sites in west of Iran have shown that there were steppes of Artemisia and chenopodiaceaes in glacial periods that represent cold and dry climate in this region. About 6500 years ago, Zagros oak forests have replaced by pistachio-oak vegetation. Studies in parts of Iran such as Zaribar Lake, Urmia Lake, Mirabad Lake and comparison with the Van Lake in Turkey showed that they have almost the same vegetation changes. In all of these studies, the end of the Yongerdryas and the beginning of the Holocene by a sudden increasing in chenopodiaceae vegetation (which represents cold and dry weather) and gramineaes ( which represents warm and dry weather) are characterized (Davoodi et al,2014). Generally, the global climate cycles and events in different parts of the Iran are rarely studied and our understanding of paleo climate and paleo ecological conditions is very insignificant. Pollen data from lakes or tree rings data have the potential for identify the paleoecology conditions in Iran.
Result and Discussion:
Climate and vegetation changes in Iran in Holocene:
Palynological studies in Komishan wetland (located on the southeastern part of Caspian Sea) has provided significant results about vegetation changes and sea level fluctuations. Delay in forest growth at beginning of the Holocene, which is in areas of eastern Turkey, there was also on the plateau of Iran and the south of the Caspian sea and in the northeastern slopes of the Alborz mountain (Gomishan). Pollynological studies and radiocarbon dating in Neur lake showed about 12800 years ago, in the late glacial ratio of trees pollens has been negligible,in the transition to the early Holocene pollens of trees and shrub vegetation such as Ephedra gradually increased. During Younger Deryas in Neur,the grasslands replaced with trees.In early Holocene at 9800 years ago Artemisia increased in Neur because it seems that there was a more milder phase in the north of Iran.  An increase in Oak and herbaceous palnts pollens such as artemisia showed that between 8000 and 9000 years ago there was wet phase in the  Neur basin. The presence of  high  amounts Alnus  pollen in the north of Iran  has shown that there were humid climate in the northern parts of Iran at 3000 years ago. Evidences suggests that highest levels of Caspian sea occurred between 1900 and 2100 years ago.

vegetation and climate in Holocene in the west of Iran

In the west of Iran during the 40000 to 20000 years ago, there was scattered vegetation (shrubs and trees). In late Pleistocene (22000 to 14000 years ago) there was arid and semi arid steppes in this region. In interglacial period in Holocene (10000-6000 years ago) precipitation increased Gramineae replaced with chenopodiaceae and Almond and Pistacia atlantica grew up such a change in vegetation indicates an increase in precipitation.In the Zagros mountain 7000 years ago Pistachio trees have existed which represent dry climate in early Holocene in this area. In mid Holocene moisture increased and vegetation was changed to Oak-Pistachio forests.In the early Holocene in western regions of Iran winter rainfall has increased and have been dry conditions in summers,In 6000 years ago in mid Holocene there was warm and humid climate in this region and Oak forests expanded. In the west of Iran, Almond and pistachio forests were more than Oaks, it indicated that humidity in spring and summer was more than other seasons in early Holocene. 
In the Last glacial  Period The Ephedraceae shrub steppes has been developed(Djamali et ak,2008).In middle of the last glacial period the water level of Lake Urmia increased, In transition between last glacial to Holocene in the west of Iran, dominant plants were ephedraceae,pistachio,Oak, Juniperus excels and Betula alba.Untill 9000 years ago dominant plants in Urmia basin was Artemisia steppes,In this basin, forests has been developed between 8000-9000 years ago.The results of Studies showed that Pollens in the west of Iran decreased in 2500 to 1500 years ago and replaced with Artemisia pollens (Talebi et al,2015). In Late Holocene Pollens such as Oak pollens has icreased (1600-1200 years ago) and there was a humid climate in the west of Iran.Also the level of Urmia lake was higher than present and the water salinity was lower.Presence of Reilla spores and low magnetic sensivity and calcium carbonate values confirmed this fact. in 1200 to 900 years ago water level in  Urmia lake decreased,  on the edges of lake ,Halophytes increased. The semi desert steppe developed in area. Pollen of Artemisia and Chenopodiaceae, Senecio vulgaris, chamomile and  Acantholimon has increased that indicate the dry and cold climate. At 650 to 450 years ago lavel of lake increased. Pollens of Juniperus represents a cold and dry climate in this region.
In the late Pleistocene and Younger Deryas period, the south Zagros had a Cold climate with steppe vegetation(Davoodi et al,2014). Davoodi et al(2014) concluded that bigining of Holocene in Parishan lake was about 10200 years ago and lasted to 8170 years ago. In this period Artemisia and Chenopodiaceae have decreased and Geraminea have increased. So we can concluded that the humidity in spring and Summer have increased but it was not enough to grow Oak trees, of course Almond and Pistachio trees grew well. Precipitation required for the growth of almond and pistachio forests is about 300 mm but for Oak forest it is 500 mm.Evidences indicated that climate in early Holocene in the southern Zagros Mountains was dry and hot. In 8170 to 7570 years ago Gramineae vegetation decreased    around Parishan Lake and cold resistant plants such as Cousinia, Umbelliferae and Cichorioideae plants has increased (والتر،1971). In this period dry climate has dominated and summer precipitation has decreased. In 7570 to 5600 yaers ago Oak forests expanded also Almond trees and Asparagus trees increased around the southern Zagros.in this period humid climate has dominated.  In western and southern parts of Iran, In 5600 to 2700 years ago Climate was warm and humid.
North west-West of Iran
The vegetation and climate of southern and southeast of Iran  in Holocene:
Distribution of grain size,petrographic characteristics and sedimentary cores chemical measurements show that:

There was a  full of water lake in Sistan basin, in the late glacial to Early Holocene. MLW(Mid Latitude Westerly currents) and ISM (Indian Monsoons) precipitations has fed the area.
In Early Holocene to Mid Holocene  ITCZ  moved to  the south so ISM weakened, as a result, dry periods started in Sistan basin. High pressure gradient between Sistan depression and Hindu Kush Mountains caused severe and persistent dust storms.
In mid Holocene to late Holocene hydroclimate regime in Sistan basin has controlled by MLW precipitations. The frequent fluctuations iin the water level of Lake Hamoon represent the unsustainable climate  in early Holocene to mid Holocene.
There are not enough information about pollens in the south-southeast of Iran and we can only reconstruct vegetation 1900 years ago. Results show that 910 years ago in this region plains turned into deserts.
Climatic anomalies in Medieval in 1145-910 years ago xerophytes grew in south and southeast of Iran. Impagidinium paradoxum in gulf of Oman Indicated the absence of ocean water drainage.

 By using pollen data and sedimental cores Miller et al (2016) reconstructed vegetation in south of Iran and reconstructed vegetation areas:
The overall dominance of Poaceae, at the expense of Amaranthaceae and Asteraceae and the decrease in clay abundance throughout the LIA suggests a shift from desert to grassland vegetation, implying wetter conditions during the LIA in S Iran. Modern ecoregions within close proximity to the coring locality where grass is a dominant component of the vegetation composition include the Zagros Mountain Forest Steppe and the Baluchistan Xeric Woodlands, where annual precipitation exceeds more than 150 mm per year, Additionally, the abundance of I. paradoxum and Dubridinium sp. is low suggesting an increased amount of freshwater discharge into the ocean. The high abundance of S. ramosus a species particularly observed where the upper water salinity conditions are reduced permanently, again suggests more freshwater discharge into the ocean near the coring vicinity. The low pollen to dinocyst (PD) ratio values during the LIA indicates more marine organic flux, likely due to increased nutrient supply promoting an increase in dinocyst populations. A decrease in Betula and a slight increase in Amaranthaceae abundance are evidenced during the last c. 100 years, which may
 
Conclusion:
Climatological and vegetative evidences suggests that cold periods in Iran have been accompanied with increase in air aridity. Probably in cold and dry periods Siberian anticyclone was strengthened and led to weakening and southward shift of monsoons. Perhaps at that time cyclones of westerlies were also weakened. In northern Iran prevailing winds were from north or northeast, have originated from central Asian deserts. Evidence of these winds are Quraqom desert sand dunes and the spatial distribution of loess deposition in Kopet Dag and north of Iran. During the glacial periods direction of prevailing winds have been northwest to northeast for tropical currents (Kehl, 2009). In the Quaternary period in Iran climate has changed several times, glacial periods has dry and cold climate than now, also many of studies concentrates on west and north parts of Iran and there is no enough data and information for the east and central parts

Abstract Introduction
Landslide susceptibility maps are of high importance in identifying and separation of landslide-prone areas and safe places for future economic development of a region located in a country such as Iran with a diversity if seismic and geological and topographical conditions. In this study by investigated the landslides occurrence influencing factors, RELR statistical model was used to preparing a susceptibility map in Izeh-Baghmalek region. Because of the fact that the influencing area of occurrence of landslides is very small in compared to the total area of the region and in practice, we can consider them as points, the RELR statistical model was used. Landslide occurrence as dependent variable and geology, land use, vegetation, elevation, slope, aspect and distance from road, settlement, rivers, and faults and etc. were considered as the independent variables in the RELR model. The effect of each parameter was calculated using the model and the probability value obtained from RELR model are presented in as susceptibility maps. The quality of the landslide susceptibility map was evaluated and according to which, it can be used for planning, management and cost reduction planning in detailed landslide studies in the study area

Abstract 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.
Materials and methods
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).
Results and discussion
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).
Conclusion
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.

Abstract In this study, the quality of groundwater resources of Farouj plain (northeastern Iran) was evaluated for drinking and industrial usage. For this purpose, 12 groundwater samples were collected to be analyzed. Temperature, pH and electrical conductivity (EC) was measured at the filed. Concentration of major anions (HCO₃^-, SO₄^2-, Cl^-) and cations (Ca²⁺, Na⁺, Mg²⁺, K⁺) was measured at the Ferdowsi University of Mashhad. Compositional types of the water samples were determined as Na-SO₄ and Na-Cl after data plot on the Piper diagram. It is also possible to identify the rock and minerals affecting the chemical composition of water by using the Piper diagram.
Dominant cation of the water samples is Na⁺ and dominant anions is HCO₃^-. Origin of sodium is attributed to dissolution of evaporate and also Na-feldspars of the Paleo-Quaternary volcanic rocks in the region. Origin of bicarbonate ion is attributed to dissolution of carbonate rocks of Tirgan Formation and also dissolution of the plagioclase in volcanic rocks. In terms of total hardness (TH), the samples are relatively hard to very hard. The most important underground water reservoirs in the study area is quaternary deposits, which partly formed by deposition of eroded Neogen red-bed sediments in the area, and affected on water quality due to their relatively high permeability to increase the water hardness.
In order to evaluate the process controlling the water chemistry, physicochemical data such as TDS,   Cl/(Cl+HCO3) and Na/(Na+Ca) were plotted on the Gibbs diagram and accordingly two main process including “Evaporation and “Water rock interaction” were determined for the source of water composition in the studied area. The Schoeller diagram showed that the water has well to inappropriate quality for drinking. Using various indices of Langelier's index, the Ryznar index, Puckorius scaling index and aggressiveness index of corrosion and sedimentation, it was concluded that the studied samples are completely inappropriate for industrial usage as they are almost sediment scaling.

Abstract Geomorphological evidences of glaciers have remained of climate changes during the Quaternary period, which is largely dispersed in mountainous areas. Renduleh and Babuleh mountains are located on both sides of a glacier valley in the Maku-Baneh Mountain on the borders of Iran, Turkey and Iraq. The hillslopes of the Renduleh and Babuleh Mountains in the west of Oshnavieh city have recorded many effects of ice actions. Evacuation of destroyed materials and transported by the glacial have formed Oshonvieh city and several villages in this region. In the research, these glaciers were examined.
Case Study
The case study is the part of the Maku-Baneh Mountains in Kordestan Province. The aspect of tectonic is located in the Sanandaj-Sirjan zone and it follows the Zagros trend, but it is conformity to the Central Iran's Stratigraphy.
Materials and Methods
This research, was performed by using topographic maps, scale of 1: 50000 and 1: 25000 Oshnavieh and Naghadeh, geological maps 1: 250,000 scale of West Azarbaijan and 1: 100000 of Oshnavieh and Naghdeh, panchromatic images pixels size 2.5 meters of IRS satellite of India Year 2016 and Landsat 7 satellite images of ETM, climatic data from Piranshahr synoptic stations, Naghadeh and Orumiyeh, Oshnavieh climatology stations and Qasemlou and Pegeland evaporation stations, Aster elevation data from Terra satellite, field observations and sampling of sediments. First, using topographic maps in the glacier areas, the position of several large and small cirques were identified. Based on the extracted cirques, the snowline was calculated using the Wright method and the field observations and visited the regions for several times. In this regard, the effects of the glacial process were identified. The position of the cirques and valleys of the glaciers and the lateral and end moraine were recorded by GPS. In order to study the environmental conditions, 8 sediment samples were taken for granulometric and morphoscopic analysis. The cumulative frequency curves and sorting of grains were calculated and thin sections were prepared from 1 mm to 1.063 micron deposits, and  used for Roundness, angularity and sorting by polarizing microscopy.
Result and Discussion
The results of the survey of panchromatic images, topographic maps and field observations have been determined the position, number and height of the Cirque in the study area. Field observations showed the maximum density of glacier cirques is at 2600-2800 meters and that most of the cirque are located in the north and northeast directions where they received the least amount of energy from the sun. There is a relatively evolved cirque on the summit of Rendeuleh, which is located in the northwest direction, but its glacier valley extends to the southwest. Based on the Wright method, the 60% of cirques are at a height 2,600 meters, so the regular snow line of the area is set at this altitude, which in most places corresponds to the end of the cirques and the glacier valleys. The sediment diagrams have the highest compliance with the parabolic environment and showed weak and poor sorting of sediments. The sediment analysis showed that the samples were graded from a mixture of fine and coarse grains, and the irregularity and sorting were weakened. According to the Convex curvature graphs, the sediment were deposited by streams which not capable of carrying them. The sorted samples taken in the region are numbered more than one such that the A, B, C, E and F samples have a value greater than 2 and the D,G and H sampled has a numerical value between 1 and 2, which, in general, is based on the Folk index, sorting is very bad. Also, the results of morphoscopic studies indicate that the percentage of angular grains is high, which is one of the characteristics of sediments in the affected areas of the glaciers. The results of the morphoscopy of the samples shown that the angular grains in all samples are above 50%, and the rounded are less than 20%.
Conclusion
Renduleh and Babuleh mountainous is located in the west and northwest of Oshonvieh, near the western neighbors. The effects and evidence of glacier condensation and erosion, especially in the northern slopes, are well visible. The research founded have shown that the permanent snow-line was at a height of 2600 meters the last glacial period, and several large and small cirques glacier with U-shaped valleys and lateral moraine in the valleys indicate glacial formation in The last glacial period. In fact the remaining glacier terraces on the left of the northern hillslopes of the Renduleh glacier valley is lateral moraine. A, B, C Samples are located at altitudes higher than the snowline and from the circus and glacier valleys. In the post-glacial period, a large part of the sediments have been transferred to Oshnavieh River by the ice-melting and the Oshnavieh city has been developed on these sediments. The identification of the glacial deposits boundary with respect to their characteristics, in addition to the scientific value of retrieve the glacial past, is important in terms of their relationship with the location of urban and rural settlements and human facilities.

Abstract In this research, 69 water samples taken from springs and production wells were evaluated to assess the groundwater quality in the Bazman, Iranshar and Espake area. Investigations were carried out using graphical methods such as Piper, Stiff, Schoeller and Wilcox and various qualitative indicators to identifying water facies and specific uses. The groundwater samples, therefore, were categorized into five water types including Na-Cl, Na-Cl-SO4, Na-Cl-HCO3, Na-SO4 and Na-HCO3. It was also found that most of the samples are undersaturated with respect to anhydrite, halite, thenardite, calcite, dolomite, gypsum and aragonite minerals. According to diagrams, halite minerals dissolution is the source of the salinity of groundwater for study area. In addition, calcite, dolomite and gypsum minerals control hydrochemical chractrestices of the groundwater in this area. According to the Schoeller diagram, some of the groundwater sample, except N3, B8, S4, S5, S11 and S14, are suitable for dinking. While, Wilcox digram shown groundwater resources are not appropriate to irrigation use. It is due to high sodium adsorption ratio (SAR) in groundwater of study area; because of its direct relation to the adsorption of sodium by soil.
Introduction
Bazman, Iranshahr and Espake regions are located in Sistan and Baluchestan province, southeastern of Iran. In this volcanic area, there are several thermal and cold springs. The use of geothermal water resources for irrigation is not commom  world wide as these resources are limit. These groundwaters having a different hydrogeochemistry. Therefore, this research investigates the hydrochemistry of hot and cold groundwater resources in this volcano area.
Materials and methods
In order to measure concentration of ions in groundwater, water samples were collected from 14 springs and 53 production wells. The wells in the study area relate to the three areas  of Bazman, Iranshahr and Espake. The water samples were poured into acid-washed polyethylene bottles which had been carefully washed out with the water of each sampling point. Then the samples were quickly moved to the laboratory and were put in a refrigerator. Electrical conductivity, pH, redox potential (Eh), and temperature were measured in situ using a portable digital EC (AQUA-TC 485) and pH (WalkLAB-TI900) meters which were calibrated before being used. The samples were then filtered to separate the suspended particles. The major ions were analyzed by using standard methodologies.
Results and discussion
EC of the water samples ranges from 507 to 10250 μmhos/cm. The Piper and Stiff diagrams suggested that the groundwater samples could be classified into five “water types”; namely, Na-Cl, Na-Cl-SO4, Na-Cl-HCO3, Na-SO4 and Na-HCO3. It was found that the groundwater samples were chiefly of Ca-HCO3 type. The water type in western springs of the study area is NaCl-HCO3. Bicarbonate shows the presence of carbonate bearin minerals in the groundwater from Jamal formation. In most groundwater samples, the molar ratio of Na/Cl  shows which this ratio is more than 1. This is due to the fact that the dissolution of sodium-containing silicate minerals especially by weathering and cation exchange has increased the ratio. The molar concentrations of HCO₃^- versus Ca²⁺ and HCO₃^- versus Ca²⁺ + Mg²⁺ are plotted. When calcite or dolomite dissolves in groundwater, water samples must be plotted on a 2:1 line. However, this did not happen which indicates that Ca²⁺ and/or Mg²⁺ decreased by direct cation exchange.
Conclusion
The hydrochemical compositions of the geothermal springs are different than those for the cold waters. Both geothermal springs have Na-Cl water type, with chlorine concentration mole more than sodium. This may be due to that the high-depth circulation of the meteoric water in the area provides an enough time for water to achiving the thermodynamic equilibrium. Then exchange of the sodium cation with the medium occurred and therfore sodium mole ratio is much less than chlorine. However the springs to western part of the study area have a NaCl-HCO3 water type, while concentration of chlorine is lower than the sodium. Bicarbonate shows the presence of carbonate bearin minerals in the groundwater. In addition, the eastern springs of Bazman which located in sedimentary rocks, have a Na-SO4 water type. It is due to sulfur bearing minerals. Also, salinity in the groundwatr is resulted from mixing and evaporate formationed. According to the Schoeller and Wilcox diagram, the water samples except S4, S5, S11 and S14 are usable for drinking, while are not sutable to irrigation use. It is due to high sodium adsorption ratio (SAR) in groundwater of study area; because of its direct relation to the adsorption of sodium by soil.
 

Abstract 1-Introduction
   Glaciers influenced by climatic factors and therefore as an important indicator in the study of climate change are studied. Although morphometric analyzes of glaciers based on the analysis of optical satellite data can provide an opportunity to measure ice outcrops, but the identification and determination of the buried glaciers underneath the Supraglacial moraines (accumulated debris on top of the glacial ice) and, consequently, the determination of the actual glacial body and their parameters, including the level and volume of the glaciers, are not possible based on optical satellite imagery. On the other hand, the existence of an ice cooling source underneath the glacial debris, which leads to a significant reduction in the surface temperature of the glacial debris, is a distinguishing feature for the separation of covered glaciers.
2-Materials and methods
   The over 2000 km long NW-SE trending Zagros Mountain belt extends from eastern Turkey to the Makran Mountains, forming a morphological boundary between the Iranian plateau and the Mesopotamian and Persian Gulf basins. The Zardkuh Mountain lies along the central Zagros Mountain Range (32°14'-32°38' N; 49°50'-50°15' E) in Chahar-Mahal and Bakhtiari province, Iran. The highest summit of this mountain chain is 4220 m a.s.l altitude. Small glaciers (mostly cirque glaciers) were first reported on the northern slopes of Zardkuh during August 1933. Other research has pointed to some glacial cirques on Zardkuh which have altitude about 3000m and located in small valleys on the N faces of the Zardkuh. Some new researches on the active glaciers of Zardkuh show the greatest glacier concentration around 1) Joft-zarde and Shahe Shahidan (Zarkuh) summits 2) around Sirdan summit and 3) Haft-tanan (Iluk) region. Based on the latest study, the current size of Zardkuh’s glaciers have estimated about 7.1 km².
   In this research, the expansion of natural glaciers of Zardkuh Mountain has been determined by the combined analysis of thermal (Thermal Infrared Sensor (TIRS) of Landsat 8), optical data (Operational Land Imager (OLI) of Landsat 8 and Quickbird image) and digital elevation data, based on Split Window Algorithm. For this purpose, the following steps are carried out: 1) Preparation of Landsat 8 TIRS and OLI images, Quickbird image and Digital Elevation Model with 10 m resolution 2) Radiometric correction and rectification of images to WGS-1984-UTM-Zone_39N 3) Detection of exposed ice of active glaciers using by short wavelength infrared and green spectral bands of Landsat and optical images 4) Creation of 3D model of active glacier by combination of DEM and Quickbird images / Landsat images 5) Estimation of Land Surface Temperature (LST) using by Normalized Difference Vegetation Index (NDVI) and Land Surface Emissivity (LSE) based on the Single Window Algorithm. The NDVI is calculated as a ratio between measured reflectivity in the red and near infrared portions of the electromagnetic spectrum. The land surface emissivity (LSE (𝜀)) is calculated based on the Proportion of vegetation (Pv) and NDVI. 6) Supervised classification of LST layer based on the sampling of ice and supraglacial deposits temperatures for each glacier (the presence of ice under sediments has already been confirmed in field visits) 7) Area calculation of ​​the glaciers based on the classified LST layer. 
 
3-Results and discussion
In this study, Land Surface Temperature (LST) layer were calculated for Zardkuh Mountain based on the single method algorithm. Furthermore, Land Surface Emissivity (LSE), Proportion of vegetation (Pv) and normalised difference vegetation index (NDVI) layers were calculated for the study area. The surface area of exposed ice of Zardkuh glaciers is detected by using the short wavelength infrared and green spectral bands by making  RGB753 color composite which its spatial resolution has improved with Panchromatic band to 15 m and 3D model of glaciers. Based on the results of this study, the area of the exposed ice of glaciers were 123 hectares. The surface area of exposed ice and buried glaciers underneath the Supraglacial moraines of Zardkuh glaciers based on the described methodology, were measured about 201 hectares in August 2017. The area of ​​the Haftanan, Joftzarde, Kuhrang3 and Khersan glaciers has decreased and reached to 32, 31, 30 and 29 hectares, respectively.
4- Conclusion
   In this paper, potential of remote sensing to study the actual extent of Zardkuh glaciers in Zagrous Mountains in Iran by estimating LST distribution with the help of Landsat 8 OLI and TIRS sensor bands provided. Remote Sensing technology data such as Landsat 8 TIRS proved as an efficient one to estimate LST. Single window algorithm methods are applied to calculate the LST from TIRS data. Based on the results of this study, the area of the glaciers (surface and buried ice) in comparison with previous studies, shows a significant decrease in the past decade.