Quaternary Journal of Iran

Abstract In desert areas high temperature and low precipitation limit growth and development of plants. Under this circumstances wind becomes the most important erosion and transportation factor in these areas. There are four great sand masses in the central part of Dasht-e-Kavir namely Rig-e-Jen, Rig-e-Sargardan (Shotori or Halvan), Rig-e-Kharturan, and Rig-e- Chah-e-Jam. These great sandy masses show an especial pattern, so that all of them are located almost on an irregular circle around Dasht-e-Kavir. Their circular alignment can be resembled to a circulation around Dasht-e-Kavir. So far, the placement of these sandy masses was interpreted under the influence of topography and stoss-side of current features around Dasht-e-Kavir. However, the elongation and combination of these sandy masses don't show a good correlation with their relative location. As a result, the main question is that: circular arrangement of sand and gravel masses around Dasht-e-Kavir was the consequence of which factors and what is the relationship between wind direction pattern on Dasht-e-Kavir and situation of these sand and gravel masses? Distribution and morphology of these sand and gravel masses around Dasht-e-Kavir is the result of currents of convergent winds under dominance of influence of thermal low pressure system during hot season. The latter issue is the central hypothesis of this research.
 
Study area
Daht-e-Kavir is located in central Iran Tectonic Zone. This plain is covered with thick clastics and evaporitic deposits in the second part of Tertiary. As a result, the topography of this plain is almost relatively smooth and vast. Among all morphological features development of four vast sand dunes is outstanding. They are known as: Rig-e-Sargardan, Rig-e-Shotori (Halvan), Rig-e-Kharturan and Rig-e-Chah-e-Jam.
 
Materials and Methods
Statistical data from meteorological stations were used to interpret wind and pressure patterns on the earth surface. Aerial photos and satellite image data were used to determine the location of sand dunes and ergs and morphology of sand dunes. Additionally, some data were gathered through field works. For investigating and analyzing climatic conditions, wind rose diagrams of the area for different time periods were prepared. According to the role of pressure as the most important climatic factor and its direct effect on generation, intensity and change in wind direction, studying the climatic systems and pressure patterns on synoptic maps is important. As a result, the data for wind and pressure patterns in three levels of 850, 1000 and HP were gathered and the maps were drawn by Grads software. According to the type of climatic patterns, the type of climatic systems and their role in distribution and morphology of sand dunes were identified.
 
Result and Discussion
Generally, speaking, general circulation of atmospheric currents in the region in the summer is under the influence of subtropical high pressure system. So, the precipitation is very scarce. In this region most of the precipitation is influenced by passage of dynamic cold low-pressure systems which pass from northern part of Iran. Passage of these currents from the northern Alborz slopes is sometimes spread over the divides of the studied basin and causes precipitation in the northern parts of this region. Sometimes warm and wet monsoonal currents from Indian Ocean affect the high lands up to 2 -3 kilometers high while confronted with low-pressure systems of mid-latitudes causing instability and showers. In the cold periods of the year, when the subtropical high-pressure system in Iran moves towards lower latitudes (lower than 20 N), passage of mid-latitudes low and high-pressure Mediterranean currents is facilitated. The result of these changes is precipitation which takes place during winter.
Intensity of sunlight, scarce precipitation and low humidity result in severe dryness in the region. This is especially in the summer when it's very hot during the days and almost cool at night. Consequently, day and night temperature difference is very high and in the dry lands up to 95% of sun rays affects the ground. Under these conditions, the high temperature difference between central parts of the Dasht-e-Kavir and mountainous regions around it results in pressure difference between these two regions and consequently causes severe convectional instability and generation of severe winds between these two regions.
 
Interpretation of rose diagrams represents that prevailing wind direction during warm periods in the northern half of Dasht-e-Kavir is often eastern. In the west of Dasht-e-Kavir the winds are northward. Then in the southern half of Dasht-e-Kavir the trend of prevailing winds is also westward that change course to southward towards the eastern part of Dasht-e-Kavir. The most important point is that morphology of the sandy features is in complete correspondence with the above mentioned directions. Comparison of seasonal rose diagrams and morphology of ergs in Dasht-e-Kavir show that summer rose diagrams have the best correspondence with the morphology of sandy features on Dasht-e-Kavir. As a result, morphology of ergs in Dasht-e-Kavir is mainly controlled by the regime of summer winds especially in July and August months. On the other hand, in cold periods, wind current system dominantly changes. The winds in this period have lower speed and are much more irregular and show more instability. As a result, they don’t have a major role in sand transportation in this period and can’t have a significant influence on the morphology of the ergs.

Abstract Characteristics of the natural environment is the most important factor for the formation of human settlements, especially in the ancient eras. Geoarchaeological surveys are the efficient way to discover the environmental features of ancient settlements at the time of their establishment. Geoarchaeology is the application of geological and geomorphological techniques to archaeology and the study of the interactions of hominines with the natural environment at a variety of temporal and spatial scales (Brown, 2008: 278). Micromorphology is one of the appropriate techniques used in this field. Chaltasian ancient enclosure is a prehistoric settlement located on the central parts of Jajrour fan and the aim of this study is the geoarchaeological survey of the Chaltasian prehistoric enclosure in Varamin Plain, using micromorphological techniques.
Materials and Methods
Varamin Plain is situated in the south sastern corner of Tehran on the alluvial sediments of Jajroud River. Chaltasian ancient enclosure is a prehistoric settlement located on the central parts of Jajrour fan. Information needed for this research obtained through a library studies (text and image resources) and field (field visit, trenching and sediment and cube sampling). One trench on the ancient mound was excavated and 22 samples from it were determined. Then, laboratory methods, including Mansel color recognition method, electronic screening, calcimetry and micromorphology were performed in order to analysis the sediments. Also, nine thin sections were prepared for micromorphology testing.
Results and Discussion
The sediment and cube sampling from the trenches on the eastern mound was performed (a total of 22 sediment samples and nine cubes from ancient mound). Most of the sediment samples are very pale and pale brown but colors of some samples are darker or lighter. Being darker is due to the presence of organic materials, particularly coal in ancient layers. Layers closer to pink are more weathered and have nodules more often than the layers with typical brown color. Also, large amount of carbonates gives white or gray color to the soil. For example, the sample 424 on the ancient mound, with white color, has the highest rates of calcium carbonate among the other sediments. After testing and analysis the grain size, it was found that the most of the tested sediments from the ancient mound are sandy silt and silty sand. Fine-grained soil is one of the most important factors influences the site selecting of the ancient settlements thus the economy and livelihood of the ancients, especially in pottery making, dependent on the soil type and existence of the majority of ancient settlements including Chaltasian ancient enclosure in the central part of Jajroud fan has proved it. In this study, man-made elements, filling, the frequency of nodules, the microscopic structure and the relative distribution are the factors studied using micromorphological techniques. The microscopic structure of all thin sections examined was complex and the relative distribution of them was open porphyric. Existence of coal in ancient layers is caused by human intervention and the increase of the amount of coal reflects an increase in the involvement and impact of human activities on sediment layers. Section number 9 has the highest amount of coal that would be caused by the use of the ancient inhabitants of this region as a place for accumulation of household waste, food waste and ash of baking pottery kilns. The amount of clay and pottery at all sections is almost the same. All nodules in thin sections studied, are typical ferruginous nodules and the maximum value was 10% at section number 8. Probably, sections number8 have been exposed longer than the other sections. The type of filling in all sections is dense incomplete and sections number 9 and 10 with 5% has the highest rate of filing. Since this type of filling has a direct relationship with the amount of calcium carbonate, therefore, these two sections have the highest amount of calcium carbonate.
Conclusion
The results showed that the maximum amount of coal, plants, filling and calcium carbonate in the section number 9 have been detected. Since existing these factors have a direct relationship with the amount of human activity in ancient layers, it can be concluded that the highest level of intervention and activities of the ancient inhabitants of the Chaltasyan ancient enclosures have been occurred at this layer. Also, granulometry tests indicated that all sediment samples are silty sand and sandy silt and it provided suitable soil for agriculture and pottery making which had significant influence on aite selecting of Chaltasian ancient enclosures.

Abstract The Sabalan volcano is one of the youngest volcanic calderas in east of Turkish-Iranian Plateau and is a young member of the Alborz Magmatic Arc (AMA). This stratovolcano is located in northwest of Iran and northern of Bitlis- Zagros Suture Zone. Turkish–Iranian Plateau covers an area about 1.5-2 million km², and it is marked by high elevations (typically1.5–2 km above sea level) and low relief compared with mountains ranges to the south and north, where convergent deformation is more active (e.g. Zagros, Alborz, Kopeh Dagh and Greater Caucasus ranges). Magmatism is an important feature on the Turkish–Iranian high plateau in the Arabia–Eurasia collision zone. The Arabia–Eurasia collision is the most recent Tethyan orogeny in southwest Asia. Some of the lavas are erupted close to the suture in the late Cenozoic initial Arabia–Eurasia collision (Kheirkhah et al., 2013). The reduction in magmatic production by the end of the Eocene and many of the recent centers in the Turkish–Iranian Plateau are indicated that the magmatism was activated since the Eocene. The Eocene and perhaps especially the Middle Eocene was a time of intensified magmatic activity within southwest Eurasia. The compositions of these rocks are typically calc-alkaline and the magmatism is interpreted as an example of arc and back-arc volcanism. Eocene and Oligo-Miocene lavas and plutonic rocks are also distributed in NW Iran and Ahar volcanic belt. The most magmatic in this plateau had activities in volcanic from the Late Miocene to Quaternary. Magmatism has occurred intermittently within SW Eurasia between the Oligocene and the present day, across much of the region north of the original suture (Kheirkhah et al., 2009).
Materials and Methods
Sabalan is a Plio-Quaternary stratovolcano spreading over about 700 km² and with elevations up to 4821 m. It is one of the eight major volcanic cones of an Oligocene to Quaternary volcanic province, which covers more than 200,000 km² in the border regions of Iran, Turkey and Azarbaijan. The Sabalan Quaternary volcanic structure is characterized by two stage development. A succession of ignimbritic and lava flows is ascribed the first stage. In the second stage, extrusion of conspicuous volcanic domes and the formation of minor pyroclastic and lava cones have taken place (Alberti et al., 1976).
Results and Discussion
The Quaternary Sabalan volcanic activities are indicated with trachy andesites which mostly are erupted from the main caldera and are interbedded with ignimberites. The youngest flows of these volcanic activities are predominated by pumice and scoria flows. Based on studied microscopic sections and geochemistry analyses by XRF and ICP methods, the young volcanic lavas consists of andesite, trachy- andesite, trachy- dacite, dacite and rhyolite with pyroclastic flows (ignimbrites, volcanic ash), which show high-K calc-alkaline nature. The Quaternary Sabalan lavas show high K calc-alkaline to shoshonitic signatures. The calc-alkaline andesitic rocks of these volcanic activities have high contents of K, Sr and Ba and resemble the high-K andesites. The content of transition trace elements (Co, Ni and Sc) in the rocks of the Sabalan is low. The available geochemical data indicate that these rocks were derived from upper mantle garnet peridotite presumably overlying the subduction zone and enriched in LILE prior to partial melting. The magma probably underwent fractional crystallization of olivine and spinel lherzolite.
Conclusions
By Geochemical studies, it is suggested that this lavas indicate some properties of assimilation, fractional and crystallization (AFC) process. These characteristics show that these lavas were erupted above an active continental margin. The data are consistent with the hypothesis of the volcanic rocks of this volcano probably being related by low-pressure fractionation involving. geochemical investigations of these rocks such as LREE-enrichment compared with HREE, Pb positive anomalies, and depletions in Ta, Nb and high ratio of Ba/Nb. These characteristics indicate that the primitive magmas were related to an active continental margin, under affected of component’s subduction of Neotethyan ocean beneath central Iranian plate. It is assumed that these rocks are originated from low degree of partial melting (<0.1) from lithospheric mantle source, which composition supposedly corresponded to garnet-spinel lherzolite. Sabalan Quaternary volcanism attributed to the events of post collisional subduction zone. It isn’t improbable that the mantle source was preliminarily enriched with REE as a result of metasomatic transformations by the component of subduction zone or crustal contamination, especially by upper crust.

Abstract Geological time has been evaporited sediments form by solar-driven concentration of a surface or nearsurface brine. Large, thick and extensive deposits were dominated by rock-salt (mega-halite) or anhydrite (mega-sulfate) deposits tend to be marine evaporites and can be associated with extensive deposits of potash salts (mega-potash). Examinations of sedimentologic and mineralogic characteristics of the closed-basin cores due to the very high susceptibility to precipitation and evaporation balance are beneficial for determination and evolution of late Quaternary sedimentary specification. Playa defined as an intra-continental arid zone basin with a negative water balance for over half of each year, dry for over 75% of the time, with a capillary fringe close enough to the surface such that evaporation will cause water to discharge, usually resulting in evaporites. The negative water balance includes all sources of precipitation, surface water flow and groundwater flow minus evaporation and evapotranspiration. Hoz-e-Soltan Lake, with 195 km² catchment area and 25-50 cm depth, locates at 85 km of southwest of Tehran-Qom highway, in Central Part of Iran. It is sited between 34º56´ and 35º31´ north and 50º53´ and 51º20´ east at western-north of Hoz-e-Masileh. The maximum superficial relief is about 1940 m to the north and 1150 to the south. It is surrounded by Ali-Abad and Kushk-e-Nosrat mountains in north and northeast, Manzarieh and Chahar mountains in west and Mohammad-Abad and Badamcheh mountains in south and southeast. Orogenic movements and volcanic eruptions at the end of Cretaceous and early Eocene led to formation of Eocene volcanics in the north and some central parts of Iran, and particularly around the Hoz-e-Soltan basin. As a result of faulting takng place following the volcanism at this area, a graben was formed, which was later filled by the salt Lake. This graben formed a closed basin, which has since become partially filled with interbedded terrigenous-clastic and evaporite sediments. The evaporate facies present conform approximately to a ″tear-drop pattern″. This research was conducted with the aim to determine sedimentary facies and identify evaporate minerals as well as the change in the type of mineral composition within the sediments that were formed during the Holocene period reflecting the balance in water input and output in the studied basin.
Materials and Methods
In this study, 9 core samples (max length 700 cm) were selected from the intact bottom of the Lake using an auger core sampler. The core samples were then dissected in halves longitudinally, underneath the sediments, Playa environment was detected. In total, 113 sub-samples were prepared from various core samples of sedimentary facies, which were then analyzed using grain and mineral analytical methods such as granulometery and mineralogy (XRD). High-resolution digital photographs of cores were performed with 12 megapixel Canon camera imaging. Samples were dried in an oven at 60 ̊C for 48 hours in laboratory. Analysis of particles larger than 63 micron and smaller than 63 micron (silt and clay) was performed by using a wet Vibratory Sieve Shaker ANALYSETTE 19 and Laser Particle Sizer ANALYSETTE 22, respectively. Also the analyses of all clastic, carbonate and evaporite minerals were determined semi-quantitative. Sedimentary components were studied by binocular Nikon microscope with a maximum magnification of 94.5 (6.3 × 1.5 × 10) and scanning electron microscope. All of analyses were done in the laboratory of Geological Survey of Iran.
Results and Discussion
After obtaining the results of different laboratory studies such as granulometery, mineralogy, chemical analysis, scanning electron microscope, morphometry and morphoscopy from 3 cores (HS1, HS2 and HS3) and processing the data, final investigations were done. Sediments in the central part of the Lake is almost entirely chemical (evaporate and carbonate) and in the margin of the Lake is detrital-chemical. Quartz is the most abundant mineral with different amounts in the studied cores. Feldspar is less abundant. The highest amounts of detrital sediments were seen in the margin of the Lake, particularly in western-north, west and western-south. There is alternation of detrital sediments with chemical and biochemical sediments resulting from the wet and drought periods. Between the carbonate minerals, calcite is the most abundant mineral as cement in the alluvial fans and sand dunes. The amount of calcite is increased from the center to the east and eastern-south of the Lake. Quartz and calcite dominated in mud flat and saline mud flat sub-environments. Halite with an area of 75 km² is the most abundant lithofacies in the Lake. There are two main types of halite: massive halite and hoper halite. Gypsum is in the lens form, semi-translucent prismatic crystals in white, grey and yellowish brown colors. Halite and gypsum dominated in salt pan and ephemeral Lake sub-environment. Generally, the colour of sediment in mud flat sub-environment is brownish red, saline mud flat is red and yellow with large crystals of diagenetic gypsum, salt pan is white, green and grey and ephemeral Lake is light to dark grey.
Conclusion
On the basis of granulometery results, 5 sedimentary types were recognized in the sub-surface sediments: slight gravel-bearing sandy mud, slight gravel-bearing muddy sand, mud, sandy mud, and muddy sand. The results of these analysis showed that the Lake sediments are composed of 3 types of sediments: detrital, carbonate and evaporate sediments. Quartz, feldspar and clay minerals dominated of detrital sediment, but other minerals such as mica, magnetite, hematite, amphibole, zeolite, anatase and pyroxene were found. Calcite dominated of carbonate sediment and in some samples aragonite were found. Calcite, gypsum and halite dominated of evaporitic minerals, but other minerals such as anhydrite, carnalite, polyhalite, tenardite, basanite and hexa-hydrate were found. 

Abstract Coccolithophores are unicellular marine phytoplankton characterized by calcareous scales called coccoliths. Cocclithophores appeared in the fossil record during Late Triassic. They live at different depths in the photic zone owing to their requirement of sunlight for photosynthesis. Their distribution in the upper water column is influenced by surface oceanic circulation and different parameters such as temperature, salinity (Winter et al., 1994).
The Gulf of Oman is located between 22 and 26°N and 56 and 62°E and opens on the Northwestern Indian Ocean and on the Arabian Sea. The general orientation of the gulf is northwest-southeast. The basin narrows down and gets shallower towards the Strait of Hormuz-the western most boundary of the Oman Sea. The Negour Area is located 25 and 20°N and 61 and 8°E.
Materials and Methods
In this study, a total of 52 surface sediments were chosen of the Oman Sea. The location of the surface sediments are presented in Figure 1. Samples were investigated using a Scanning Electron Microscope (SEM) (model: LEO 1450 VP with maximum 30v, Sputter coater (Au-Pd) model: SC 7620) (Plate 1). In order to control the SEM preparation and to study general changes in the floral composition, a light microscope study was also undertaken using simple smear slides (Bown and Young, 1998). 
A wedge-shaped piece was cut of the dry filter, mounted on an aluminum stub and sputter coated with gold. The samples were examined with an Olympus BH-2 microscope polarizing light at a magnification of 2500X (Plate 2). For the distinction of some species such as Calcidiscusleptoporus (Murray and Blackman 1898) Leoblich and Tappan 1978 and Emilianiahuxleyi (Lohman 1902) Hay and Mohler, in Hay et al., we used gupsum plates. For the preparation of smear slides, at first the area around the sample was cleaned. A little amount of sample was cut completely and placed on a drop of distilled water over a glass slide. Next, the relatively concentrated solution was scattered using a tooth pick with two flat sides and dried in oven rapidly. Then, the slide was labelled and a lamella was placed over the dried sample and adhered with specific adhesive similar to the procedure used for preparing of marl and gypsum samples. It can be used for other lithologies except for hardest sediments. To ensure accuracy, 300 nannofossil specimens were counted per slide (relative abundancy). The determined species were photographed by a digital camera and then counted up to 300 numbers that its diagrams have drawn for paleoecology interpretations.
Discussion
Calcareous nannofossils are generally well preserved in all the samples. In this study we have 3 groups of nannofossils. Some species have a high abundance such as Gephyrocapsaoceanica Kamptner 1943, Helicosphaeracarteri (Wallich 1877) Kamtner 1954, Pseudoemiliania lacunose (Kamptner, 1963) Gratner (1969c) and Emilianiahuxleyi (Lohman 1902) Hay and Mohler, in Hay et al. Some species are rarely found such as Umbilicosphaerasibogae (Weber-van Bosse 1901) Gaarder 1968, Braarudosphaerabigelowii Gran & Braarud, (1935) Deflandre (1947), Calcidiscusleptoporus (Murray & Blackman 1898) Leoblich and Tappan 1978, Calcisoleniamurrayi Gran 1912, H. sellii Bukry & Bramlette (1969b), Pontosphaeramutipora (Kamptner, 1948) Roth (1970) (Fig. 2) and some species are reworked from the Cretaceous and Neogene such as Sphenolithusabies, Sphenolithusciperoensis, Sphenolithusmoriformis, Sphenolithus radians, Reticulofenestraminuta, Reticulofenestrapseudoumbilica, Reticulofenestraumbilica, Discoasterbrouweri and Discoasterdeflandrei.
Rrelative abundances of the species are as follows (Negour area):
1. Abundant taxa: The most abundant group is represented by Gephrocapsaoceanica Kamptner 1943 (average 75.66%), Helicosphaeracarteri (Wallich 1877) Kamtner 1954 (average 4.3%), Gephyrocapsaericsonii McIntyre & Be (1967) (average 5.9%) Pseudoemilianialacunosa (Kamptner, 1963) Gratner (1969c) (average 5.19%) and Emilianiahuxleyi (Lohman 1902) Hay and Mohler, in Hay et al. (average 2.02%).
2. Rare taxa: In this area, some species are rare, such as Helicosphaerasellii Bukry & Bramlette (1969b) (average 0.16%), Calcidiscusleptoporus (Murray & Blackman 1898) Leoblich and Tappan 1978 (average 0.95%), Umbilicosphaerasibogae (Weber-van Bosse 1901) Gaarder 1968 (average 0.91%), Pontosphaeramultipora (Kamptner, 1948) Roth (1970), (average 0.12%), Coccolithuspelagicus (Wallich, 1877) Schiller (1930) (average 0.86%), Gephyrocapsamuellera Breheret (1978a) (average 1.68%), Gephyrocapsaparallela Breheret 1978 (average 1%), and Braarudosphaerabigelowii Gran & Braarud, (1935) Deflandre (1947) (average 0.2%).
 
The distribution of G. oceanica Kamptner 1943 mirrors warm water masses and shows a high Primary Productivity. High abundances of this taxon are located in marginal sea depositing in low latitude, shallow basin and near to coast. Coccolithuspelagicus (Wallich, 1877) Schiller (1930) is generally considered a cold-water indicator in high latitude. Gephyrocapsamullerae Breheret 1978 is considered a cold-water species (Kaemo and Sato, 2000). H. carteri (Wallich 1877) Kamtner 1954 consider it a warm-water species (Roth, 1994). Bigelowii Gran & Braarud, (1935) Deflandre (1947), which in the Mediterranean Sea seems to be related to turbidity of near shore waters and/or to low salinity in surface waters (Svábenická, 1999).
In this study, high abundancy of G. oceanica Kamptner 1943 suggests, Holocene sediments in the Negour areas were deposited in the warm waters and the Oman Sea were shallow basin and with high Primary Productivity. High abundances of this taxon are located in marginal sea deposited in low latitude, shallow basin and near to coast. G. muellerae Breheret 1978 and C.pelagicus (Wallich, 1877) Schiller (1930) species with very low abundances represent the sediments is deposited in low latitude and warm climate. Abundancy of H. carteri (Wallich 1877) Kamtner 1954 in surface sediments of Negouraera can be confirmed that this area is a warm basin with high productivity of calcareous nannoplanktons. Due to the low abundance of B. bigelowii Gran & Braarud, (1935) Deflandre (1947) that is rare in the samples has been observed. It shows high salinity in the surface sediments of this basin.
Results
In current study, samples of the Oman Sea (Negour area) surface sediments were selected and after their preparation were studied and photographed. For the first time, 10 genera and 15 species introduced in this area. Some nannofossils are the dominant taxa, such as Gephyrocapsaoceanica Kamptner 1943, Pseudoemilianialacunosa (Kamptner, 1963) Gratner (1969c) and Helicosphaeracarteri (Wallich 1877) Kamtner 1954. Some species are the rare taxa, such as Braarudosphaerabigelowii Gran & Braarud, (1935) Deflandre (1947). In this study, we also observed many reworked species, specially mostly of them belong to Neogene. Based on the fossils founded and low diversity of them, we concluded Oman Sea (Negour area) is a marginal sea deposited in low latitude, shallow basin and near to coast. This basin was suitable for productivity of calcareous nannofossils with eutrophic conditions.

Abstract In the recent decades, with increasing in human need to produce more food and their encountering with high risk geological phenomena like earthquake and bioenvironmental pollutions, the importance of the quaternary system and realizing its different aspects for geologists were increased. This research considers the scientific phenomena occurred in Hashtgerd area. It is located between 35°52′30″N and 36°00′00″N latitudes and 50°37′30″ E and 50°45′00″E longitudes. Topographic elevations in the province vary between 1310 and 1610 m. This area has placed in the southern slopes of the Alborz Mountains and in the northern edge of the central desert of Iran and 40 km west of Karaj. Morphologically this area located on an alluvial fan which is 16 km². In the northern part, sediments seem older and brighter and have higher cementation and often are related to Paleo-quaternary sediments. The young quaternary sediments have been placed on this alluvial Fan and the sediments are getting more loos and more red toward south. The age of deposits in this area is Pliocene up to present. The Pliocene deposits are the oldest and the agricultural soil and the alluvial deposits are the youngest. The most available dominant lithology is also Tuff.
Materials and Methods
After determination of study area, the geological maps (Karaj 1:100000), topography maps (Hashtgerd 1:25000) and Aerial photographs of the area in the scale of 1:50000 were provided and investigated. After second time field study for getting familiar with the area, access routes and determination of sampling points, 34 point sampled and the coordinate of these point were recorded. The samples were sent to the laboratories of applied geological research center of Iran. For sediment grading test, shaker sieve, for fine sediment grading tests, lasers and XRD test for identification of clay minerals were used in order to understand their sources. In each sampling station physical feature of sediments has been noted and 20 rubbles above 3cm in size sampled for analyzing shape, size using caliper and also their rounded and sphericity. Required Cumulative graphs (in phi and MM) for each station was calculated by the Sediment Sizer software. Sedimentary structures of the region, the granulation and direction of the ancient flow have been studied and the photographs were taken of all of the features. To obtain the ancient flow direction in the sediments, measurements were carried out by compass include pebbles deep and strike, then using obtained data from the region and by help of Rockwork software, the direction of ancient flow has been determined. 
Results and Discussion
In the most of stations, the grain size varies between 20 cm up to sand, silt and clay. So that at the beginning of fan, grain size are coarser and closer to the end grains, the grain size are smaller which indicates high energy in the upper part of the fan and low energy in the final part of the fan. Pebbles are often made of tuff and the fabrics are more Imbrications. The color of sediments due to deposition in the oxidation environment is mostly red. The grading results show that 56% of deposits are muddy sandy gravel, 29% of them gravelly mud, 9% muddy gravel and 6% gravelly muddy sand. Pebbles in this area vary from very angular to very round and their sphericity vary from slightly stretched to almost isodiametric. Roundness and sphericity of grains increases in the region with increasing in distance from the source. More than 90% of samples placed in positive category based on tilting or asymmetry and distribution of the grains. Positive tilting and bad sorting is characteristic of alluvial deposits and alluvial fans. This is due to large amounts of suspended materials such as silt and clay in the environment that after sedimentation, large amount of this material remained in it and caused bad sorting and positive tilting of sediments. In terms of grains form, it is not seen any specific trend in sticks and blades pebbles, but the percent of iso-dimention pebbles increases from east to west and the percent of disc form pebbles increases from north to the south.
Conclusion

According to the Folk nomination 1974, more than 50% of deposits in the measurement stations in the area are placed in the range of muddy sandy gravel indicating the sediments are near to their origin.
Very bad sorting and positive tilting in the sediments are characteristics of the alluvial fans.
The spherical and rounded shape of the grains from north to south and east to west of the region increases and this represents an increase of displacement in the sediments in this direction and shows the direction of ancient flow direction (northeast - southwest) on the region.
Fractures of the cumulative curves in different stations presented three sources for deposits in the region.
More than 70 percent of the constituent particles of sediment in the area are related to the Tuffs. This indicates the main source of Karaj Formation sediments.
Disc form pebbles increase from north to south and pebbles with equal dimension increase from east to west in these stations related to the way that pebbles move and also their lithology.
Based on XRD test results existence of Sio2 in Tuffs, causes the highest frequency of quartz minerals. Calcite and feldspar are the highest abundance after Quartz. Existence of Chlorite in the most of stations also confirms dominant lithology of Tuff in this area.
The ancient flow direction in more than 90% of the measurement stations is North East - South West.
All plotted graphs used for identifying ancient flow direction are modal ionic with the high dispersion and indicate alluvial fan environment.

Abstract The Earth's current surface forms and phenomena are the result of climatic processes of last periods. These processes, because of climatic variations of regions, had different effect on the earth surface. The origins of the modern forms of earth related to transformations of two million years ago that scientists have called it the Quaternary period. Study of glacial erosion system is noteworthy for two view: first, there is still frozen areas in our time; Second, because during the Quaternary glacial, glacier surface was extended to today, therefore were involved in the formation of large areas that have already been released from the glacier. The case study is Gorganrood basin.
Materials and Methods
The geomorphic forms in such a loess hills, circus glacial and karst phenomena were studied environmental changes. The determined based on satellite images and topographic maps, circus glacial of area and determined snowline by the method of Wright in the last glacial period, then, based on the region gradient (high temperature) was drawn the map of isotherms presented by using of relationship and height of permanent snowline of area in the quaternary. One of the ways it can be determined is the permanent snow line in the cold Quaternary periods, Wright's method.
Discussion
According to calculations done of the standard error rate is less of linear than exponential relationship between rainfall- height, the regional climate is such that the results of the estimation of precipitation for the basin heights follow greater than exponential functions. The results of studies on the Quaternary climate of area and present time indicated that the mean annual temperature at the present time varies between 17.7° C in the plains to 6.8° C in the highlands. After the reconstruction was obtained an average temperature in the Quaternary period of about 3.7° C in low- height areas and about 7.3° C in the highlands. Using relationship annual temperature and altitude, zero isotherms or the permanent snow line curve, is obtained equal to 4175.8. Considering the past temperature conditions, evaporation rate was much lower than today, although precipitation may no significant difference with present. Going back the Caspian Sea, while its level changes isn’t subject to the terms on the open seas; indicates wet and dry climatic conditions  in the region during the Quaternary.
Conclusion
By comparing the present thermal conditions and Pleistocene period, we concludes that the temperature difference in the region is 10.4°C. Weighted average temperature of area in the past and the present is respectively of 4.4 and 13.9°C. As a result, the temperature difference between the present and the Quaternary Period in the basin is about 9.4°C. According to the evidence and morphological features of the region and climatic conditions for their formation, came to the conclusion that moisture conditions has been noticeable in the past. So, today existence evidence as lapie, alternate layers of loess and river sediments in fluvial terraces (Aq Ghomayshi), deposits that originated from the bottom of lake, river and glacier interactive Morin lower part of the local and regional Los confirmed the weather conditions.