نشریه کواترنری ایران
پیاپی 29 (بهار و تابستان 1402)

Chalus Road, as one of the main axes of communication between the north and south of Central Alborz, has always witnessed the occurrence of numerous rockfalls and this causes countless damages. In this article, the method of dispersion and the reasons for the occurrence of these spills are investigated. For this purpose, the method of risk zoning of rock fall using rock engineering factors has been used. The results show that between the Karaj Dam and the beginning of the urban area, there are at least nine main areas where rock falls affect the road axis. Asara shales, middle tuff member, and Quaternary units respectively have the highest amount of rockfall origin. Except for some areas, there is no defined connection between the tectonic fracture zones and the starting points of rockfalls. Statistical studies show that most landslides occur at the end of winter and the beginning of spring. Regardless of the fact that tectonics has caused the fragmentation of the rock units of the region, the time of occurrence of the events shows their direct relationship with the Quaternary climate. It is suggested that the road department implement stability systems and rockfall control in identified high-risk areas in order to prevent future disasters

Bandar Genaveh earthquake accured in the foredeep of Zagros, as it is one of the most active seismic belts of fold and thrust belt in quaternary (Etemad-Saeed et al., 2020). Major deformation in this zone is caused by the development of blind thrust which cause the growth of folds and the subsequent increase and intensity of orogeny (Berberian 1995). The main purpose of this research is to investigate the vertical surface changes associated with the earthquake using the Sentinel 1 satellite radar.The area affected by the earthquake includes a series of double-plunge folds, extending northwest-southeast.This area is located on BolKhari anticline with the northwest-southeast extension as one of the surface deformations in the foredeep of the Zagros orogenic belt (Sanaei et al. 2019).

In order to calculate the amount of vertical displacement during an earthquake, two radar images of the Sentinel 1 satellite with IW mode on April 14 and 26 have been used (https://sentinel.esa. int/web/sentinel/missions/sentinel-1). Each Sentinel 1 image has three IWs and each IW contains 9 bursts. The studied area is covered by IW3 and parts 6 to 8 of the obtained images. The extraction process of vertical displacement was done using SNAP (https://step.esa.int/) software.

The output image of the displacement before and after the earthquake shows a surface change with a maximum vertical displacement of 16.5 cm and negative 0.9 cm from the satellite. In other words, the area affected by the earthquake has risen by 16.5 cm and subsided by 0.9 cm. These surface changes are observed in the form of an ellipse with a large diameter extending northwest-southeast and parallel to the Golkhari anticline and at the end of its northwest plunge. This displacement ellipse is spindle-shaped with the elongated part towards the northwest.In order to investigate the changes in the vertical movement of the earth's surface, two profiles were drawn in the two directions of northwest-southeast and northeast-southwest, parallel to the major and minor diameters of the deformation ellipse A-Bprofile along the small diameter shows a subsidence along the northeast and asymmetrical uplift with a lower slope in the northeast and a higher slope in the southwest part. Profile C-D, which is drawn along the southeast-northwest direction and shows a slight subsidence at the southeast end and an asymmetric uplift with a greater slope in the southeast part.In general, the following evidence can be evidence to the progress of the orogenic foredeep towards the southwest and northwest, or in other words, the growth of the Bolkhari anticline in the direction of the northwest caused by growth of a blind trust fault during Genaveh earthquake.1- Displacement profiles show a subsidence in the southeast and northeast and an asymmetric uplift with extension to the northwest and southwest. This displacement can be seen as uplift along with the dextral movement caused by the thrust fault with the progress of deformation or rupture of the fault from the southeast to the northwest parallel to the axis of the anticline.2- The highest uplift has occurred at the end of the northwest plunge of the anticline, which can be seen as evidence of the progress of this plunge towards the northwest.3- The epicenter of the earthquake (USGS as a base) is in the northeast of the displacement ellipse and even other are located either in the southeast or northeast part and indicate the starting point of rupture from these parts to the south and northwest.4- The most destruction and damages are related to the areas and villages located in the northwestern part of the anticline and in the area of the most surface displacement, which are well matched.5- The dispersion of aftershocks shows their concentration on the area with the highest uplift. Other aftershocks with less concentration are scattered in the form of a crescent from the southeast to the northwest and on the northeast slope. This pattern of aftershocks can be an evidence of the existence of the main fault with the northwest-southeast extension with a slope towards the northeast, whose effect started from the northeast and continued parallel to the long axis of the deformation ellipse.6- Almost half of the displacement ellipse is located beyond the mountain-plain border and in the plain's edge, which indicates the uplift of the plain, or in other words, the joining of these parts to the mountain front and the progress of a deformation front.

The radar interferometric analysis shows a vertical surface deformation with a spindle-shaped ellipse parallel to the Bolkhari anticline and with a maximum elevation of 165 mm along the northwest plunge of this anticline and on the border of mountains and plains. Comparing displacement ellipse with mainshock, aftershocks, surface destruction and mountain-plain boundary shows the uplift and progress of the mountain boundary towards the plain in the northwest and southwest with the growth of the Bolkhari anticline.

Introuduction:

The Iranian plateau is located in the middle part of the Alpine-Himalayan orogenic belt, and it is one of the active regions of the world (Agard et al., 2005; Allen et al., 2004; Berberian and King, 1981). The Zagros orogeny was formed in the western part of the Iranian plateau by the closure of the Neo-Tethys Ocean and collision of the Arabian and Eurasia plates (Agard et al., 2011; Jackson, 2011; Berberian, 1983). The Zagros orogeny is subdivided into four major zones from the NE to the SW: the Urumieh-Dokhtar Magmatic Arc (UDMA); Sanandaj-Sirjan Zone (SSZ); High Zagros Belt (HZB) and the Simply Folded Belt (SFB) (Mohajjel and Fergusson, 2013). The study area around the Hamedan city is located in the Sanandaj-Sirjan zone, and the perpendicular component to the Zagros trend has caused the formation of major reverse faults.There are many faults in the south-eastern part of the Hamedan city and they generally have a reverse mechanism and some of them have entered the city at the NW termination. These faults include Siahkamar-Alavi, Yalfan-Arzanfood, Keshin-Simin, Tafrijan-Mangawi and Anglas-Varkaneh faults. Generally, no detailed structural and geomorphological study has been done on these faults. Therefore, the aim of this study is to investigate the morphotectonics evidences related to the southeast faults of the Hamedan city using the fractal pattern of the faults and measuring the morphometric indices and field observations.

The data used in this study, to calculate the morphometric indices and fractal dimensions of faults, were the geological maps, digital elevation model (DEM) and field observations. To investigate the active tectonic associated with the south-eastern part of the Hamedan city, the ASTER digital elevation model (30-m resolution) have been used to drainage and basins extraction. Then, the study area was divided into 40 basins for calculating the morphometric indices. Then, the stream length gradient index (SL), hypsometric integral index (Hi), basin shape index (Bs), drainage basin asymmetry factor (Af) and transverse topographic symmetry index (T) have been calculated and the corresponding map were constructed. Then, these maps are combined using hierarchical analysis process (AHP) to construction a final map of relative tectonic activity.

Fractal dimension diagrams of faults in four box of the study area are calculated as: Da=1.5724, Db=1.5428, Dc=1.6551, Dd=1.6864, De=1.8088, Df=1.6436. As a result, the fractal dimension related to box b shows the minimum value (1.5428) and the fractal value of box e shows the maximum value (1.8088). Therefore, it can be concluded that the amount of fractures has increased from the NE to the SW and a high density of faults is observed in the south and SE parts of the Hamadan city. According to the values obtained from Af index, 12 basins are classified in class one, 6 basins in class two and 22 basins in class three. Several basins in the eastern part and two relatively large basins in the northern and southern parts of the studied area are also classified in class one. According to the values obtained from Bs index, three basins are in class 1, five basins are in class 2 and 32 basins are in class 3, and the lithology of the region (slate and phyllite) may be effective in this classification. According to the values obtained from Hi index, in the study area, most of the basins, except for two basins in the northeastern part of the studied area, show low relative tectonic activity. Results of T index indicate that 13 basins are classified in the first class, 26 basins in the second class, and two basins in the third class. And most of the basins, especially in the central part, have high to moderate tectonic activity. The western basins of the region have high values of SL index, which shows the high tectonic activity of the region. Ten basins in the central and south-western parts of the study area are classified in class one, and most of the basins in the eastern half of the studied area are classified in class three with low relative tectonic activity. Based on the final map of relative tectonic activity, the eastern half and also the northern part of the study area show moderate to low relative tectonic activity and these parts are divided into class two and three. Most of the eastern half parts of the study area are classified in class 3 with low relative tectonic activity. The western half of the study area and especially the central, southern and southwestern parts are classified in class 1 with high relative tectonic activity.

There are several faults with a general NW-SE trend in the southern and southeastern parts of the Hamedan city, which have caused the deformation of the rocks in the study area. The density of fractures increased from the northeast to the southwest of the study area, and the highest density of faults is observed in the southern and southeastern parts of the Hamadan city. In the northern and northeastern parts, due to the presence of recent deposits, the density of fractures is low, indicating low tectonic activity. The field evidence of these faults and fractures are observed as the fault zones and numerous fractures. Also, the formation of asymmetric basins and thrusting of different units are other geological effects related to these faults in field observations. The Yalfan-Arzanfood fault with the reverse mechanism has caused thrusting of the andalusite-schist units and Cretaceous limestone over the slates. The NW termination of this fault has passed through the north-eastern part of the Ekbatan Dam and has caused deformation of the adjacent units of the dam. The Keshin-Simin fault has created numerous fractures with a relatively parallel pattern in the schist units. These fracture zones are more than one meter in some parts and reach several centimeters close to the main fractures. The north-western termination of this fault cuts the Hamedan city from the south-eastern side and there is a large concentration of population along this fault.

Burial of urban waste is one of the main problems of the current century. To the extent that it has affected the vital resources of human life. Langrod City in Gilan province, like any other city in the world, is involved in the problem of urban waste. Failure to set up the compost plant of this city in the Atakor region has caused a huge amount of waste to be stored and the infiltration of toxic leachate for more than a decade and many problems for the residents. The purpose of this study is to investigate the pollution status of Quaternary soils in the region. The method of this study is based on eight pollution indices including land accumulation index (Igeo), enrichment factor (Ef), modified pollution degree (mCd), pollution factor (CF), pollution load index (PLI), toxic risk index (TRI). , modified hazard quotient (mHQ) and potential environmental risk (RI). The results show that the quaternary soils of the region are contaminated with heavy metals. Both earth-born and man-born factors have played a major role in these pollutions. Erosion of metamorphic units is the main factor in the accumulation of some heavy metals in the form of ground deposits. The location of the waste depot can be considered the only man-made factor of pollution in the region. It should be noted that, except for the two metals lead and zinc, the contribution of man-made pollution is much lower than the earth-made factor. Setting up a compost factory and building a sewage drainage network can have a significant impact on reducing the rate of pollution.

Mass movements include all movements that occur under the influence of mass weight. The effect of fault zones and tectonic activity on landslides and the relationship between them can be evaluated by examining the density of landslides in the fault zone and their boundaries and the impact of tectonic activity on landslides. The impact of tectonic activity by the occurrence of an earthquake and the creation of a driving force, tectonic uplifts, the creation of conditions and materials prone to landslides through the creation and development of fractures and cracks caused by faulting, the creation of cracks and fissures in rocks and acceleration The process of mechanical and chemical weathering, creating gouges and cutting faults; Increasing the permeability of rocks is a change in the amount and direction of the slope of the geological and topographical layers.

The study scope includes the entire country. The location of all the landslides detected in Iran and the known faults of Iran, the slope of the landslides and field observations and technical investigations of three cases of landslides near the faults have been investigated. The research method in the present study is based on library studies and field observations. In this regard, the information related to the state of geology, tectonics and landslides that occurred in Iran is examined in a library form, and then the information of previous landslides has been collected and compared to Field investigation of old and new landslides is discussed. After completing the geological information, faults, landslides and their location, he analyzed the data and analyzed and compared the location of landslides with faults using Arc Gis software. And the slope of their place of occurrence is done. Also, as an example, several cases of landslides that have occurred in the area of ​​active faults have also been investigated and the effect of the fault zone on the occurrence of landslides will be analyzed. Finally, by analyzing the results of comparing the occurrence of landslides with the location of the faults, the evaluation of the active tectonics is carried out.

The relationship between tectonic activities and the occurrence of landslides has been investigated by different researchers and confirmed in different regions. Therefore, considering that tectonic activity is caused by the occurrence of earthquakes and the creation of a driving force, tectonic uplifts, fractures and crushings caused by faulting, the creation of cracks and fissures in rocks and the acceleration of the process of mechanical and chemical weathering, the creation of fault gouges and cutting A fault as a material prone to landslides, increasing the permeability of rocks, changes in the direction and slope of geological layers, etc., cause landslides, the relationship between tectonic activity and landslides was investigated. Therefore, by comparing the location of the landslides detected in the country with the active faults of the country, it was found that the density of landslides is higher in the area near the active faults. As it was determined in the observations and field investigations of three selected landslide samples in Zagros, Azerbaijan and Alborz region (including the landslides of Qala Rostam, Kafcherin and Qafe Bala Qala), the activity of faults causes fractures, crushing, increased permeability, Changes in the slope and layering of rocks, and most importantly, have caused landslide-prone materials. However, it was not possible to convert this impact into quantitative data due to geological conditions and lack of data, and it was enough to interpret and describe this impact qualitatively. Also, by examining the location of the landslides that occurred in the country and the slope of the landslides, it was found that a high percentage of landslides occurred at slopes higher than 15 degrees, and qualitatively, it can be related to the slope and elevation of the mountain. established with tectonic activity and described the effect of tectonic activity on the occurrence of landslides.

By comparing the location of landslides detected in the country with active faults in the country, it was found that the density of landslides is higher in the vicinity of active faults. So that in the range of 500 meters and 2000 meters of active faults, the number of detected landslides is 65% more than the areas far from the fault, and a high percentage of landslides occurred at slopes higher than 15 degrees, which is due to It is influenced by tectonic activity due to the increase in the slope and elevation of the mountains. According to the field investigation of three landslide samples, the effect of fault activity on the creation of landslide-prone materials was determined. Therefore, one of the main factors of the occurrence of landslides and the frequency of their occurrence in the fault areas and close to the faults can be considered as the effect of tectonic activity and faults, which through the occurrence of earthquakes and the creation of a driving force, tectonic uplifts, fractures and crushing caused by faulting, creation of joints and cracks in rocks and accelerating the process of mechanical and chemical weathering, creation of fault gouges and fault cuts as materials prone to sliding, increasing the permeability of rocks, changes in the direction and degree of slope of geological layers, etc. In other words, it can be said that tectonic activities have increased the occurrence of landslides in the country. In terms of the vulnerability of residential areas and other important facilities located near active and quaternary faults, in addition to seismic waves and surface rupture during an earthquake, they are also threatened by the risk of landslides. Therefore, it is necessary and necessary to adopt engineering measures in the construction of houses located in fault zones to prevent damage caused by landslides, as well as not to build on sloping land and away from the boundaries of fault ruptures.

In order to investigate urban soil areas of Isfahan for heavy metals, in the summer of 2022 from 23 sampling stations and after preparation, the samples were chemically analyzed by ICPOES method with 4-acid digestion. The soil accumulation index shows that CdA metals have a large consumption rate. The results of the enrichment factor of all metals indicated that the origin of all the metals except Pb, Cd, and As studied in the soil of urban areas was terrestrial and their accumulation was terrestrial. The pollution factor results showed the highest pollution factor for Pb and Cr metals. The results of the pollution load index showed that 8 samples have pollution and 15 samples have no pollution in the soil of the urban areas of esfahan. The results of the study of ecological risk and environmental risk of heavy metals showed that all the studied samples, except for 9 samples for Cd metal and 1 sample for Pb metal, have low ecological risk. Also, the findings of the study of the environmental risk index according to the values obtained for the soil of the urban areas of Isfahan showed that the environmental risk of heavy metals is low. According to the results, it was found that the risk potential of heavy metals in the soil of the studied areas to cancerous and non-cancerous diseases is higher in children than in adults.

Bedrock features, such as mortars, cup-marks, cupules, grooves, slicks, basins, and grinding surfaces, are a type of rock alteration. These features have been observed in Paleolithic contexts and were used in certain regions until the 20th century. Unlike many other categories of archaeological remains, bedrock features have received relatively little scholarly attention. Until recently, there have been only a few focused field projects dedicated to studying them. This is partly because of the challenges in dating these features and identifying their cultural context. This research focuses on investigating bedrock features discovered during an archaeological survey of Paleolithic caves and rock shelters in the Izeh Plain, located in northeastern Khuzestan. These features, which are found on exposed rock ledges and floors of the caves and shelters, do not have a clear association with datable remains. The goal is to understand the morphological variation of these features and determine their relative dating.

Izeh is an alluvial plain situated in the northeastern part of Iran's Khuzestan province. It has an average elevation of 750 meters above sea level and covers an area of 140 square kilometers. This region is a section of the folded foothills of the Zagros mountains, and its plains consist of scattered sediments. Archaeological surveys have revealed the significant potential for studying the Stone Age in Izeh Plain. After Wright's brief visits in the 1970s (Wright, 1979), the exploration for caves and rock shelters in Izeh was resumed and carried on in the 2000s and 2010s. As a result, over 150 caves and rock shelters from the Upper Palaeolithic and Epipalaeolithic periods were documented (see Jayez, 2023). During the most recent survey season, in addition to caves and rock shelters, we also documented 39 rock cut installations, specifically bedrock mortars and basins. These were mostly found in the outer areas of the sites. Similar features have been documented in Late Paleolithic sites in the Zagros region (see Alibeigi, 2013: 53; Conard and Ghasidian, 2011: 36, 40; Heydari-Guran and Ghasidian 2020: 10). At this point, it is not possible to determine an exact date for these findings. They were discovered in open areas outside of caves and rock shelters, so it is difficult to confirm if they are from the same time period as the prehistoric cultural remains.

The bedrock features of Izeh Plain can be categorized into three types: cup-marks (round shallow holes), mortars (round, usually bowl-like and deep holes), and basins (oval or round shallow features), each serving different purposes. Similar features have been mostly reported from Natufian sites, which are found in various geographical and ecological areas. These include the Mediterranean eco-zone, the Negev desert, the Jordan Valley, and the high sandstone mountains in southwestern Jordan (Nadel and Rosenberg, 2010). The large-scale production of human-made bedrock holes became common during the Late Natufian period. The dominant types were deep narrow specimens, as well as smaller and/or shallower examples. During the PPNA, the most common type of feature was the small and shallow cup-mark, often found on slabs placed on house floors. The production and use of these bedrock features continued into later prehistoric periods, such as the Chalcolithic and Iron Age of the Levant, and even in later historical periods (van den Brick, 2008).In Iran, there have been reports of similar bedrock features in the southern and central Zagros regions, which are believed to date back to the Epipalaeolithic Period (Conard and Ghasidian, 2011: 36, 40; Heydari-Guran, 2014: 228-229). Neolithic sites such as Chia Sabz and Teppeh Sarab Yavari have recorded bedrock mortars in their surroundings, but their dating is uncertain (Darabi, 1395; Alibaigi, 2013).Some scholars believe that, according to extensive research on the bedrock features of the Levant, during the early Neolithic period, activities such as grounding and pounding started taking place in residential areas. This could indicate a practical division of tasks, with noisy and messy activities being done in open public spaces, while the final stages of processing were carried out in enclosed spaces (Belfer-Cohen and Hovers, 2005: 303).

Ground stone assemblages, including portable and bedrock features, were crucial in the Neolithization process in Western Asia. The increasing sedentism observed during the Natufian period is often considered a significant factor in the development of ground stone tools. These tools, particularly the larger ones, may have served as fixtures within specific sites. Their presence, designs, and on site may have varied depending on the level of pre-planning and anticipation of site re-occupations. The different shapes of bedrock features near caves and rock shelters in Izeh Plain align with the relative dating of these archaeological sites. This dating suggests that the region experienced a high level of settlement during the late Paleolithic and early Neolithic periods. These features likely played a significant role in the semi-sedentary lifestyle of the last hunter-gatherers. They were also likely used during the beginning of the Neolithic Period and in later occupations of the Izeh Plain.

Human societies have always been influenced by climatic and geographical factors of their ecosystems throughout history, so interdisciplinary studies to identify these influences will help to understand the cultural changes of ancient societies. One of the geographical factors affecting the ancient sites of the northern regions of the country is the Caspian Sea. The separation of this lake from the high seas has caused the sea level of this sea to increase slowly and when it reaches its maximum height, it decreases with the same rate. In this study, an attempt has been made to combine the information obtained from marine sediment survey studies with archaeological evidence and findings, as far as possible, to investigate the effects of Caspian Sea water regressions and advances on the location of prehistoric settlements in the Mazandaran region of The Paleolithic period to the Iron Age. For this purpose, studies on the altitude range of these changes were reviewed and the results obtained in the field of paleontology of Caspian Sea level fluctuations were combined with the results of archaeological studies in the region. Simultaneously with the fluctuations of the Caspian Sea water during the Pleistocene and Holocene, the location of prehistoric sites and populations on the southern shores of the Caspian Sea changed relative to seawater, and with the advance of seawater, the remains of previous evidence are buried under sediments.

The Persian Gulf is an incredibly important and sensitive ecosystem that has garnered increased attention in the 21st century due to ongoing changes in international relations. There is an evident need for marine geological studies in this area, given the development plans, limited understanding of the seabed's geological condition, abundant oil resources, environmental concerns, and pollution of potentially toxic elements along the Persian Gulf's shores. The Persian Gulf holds a significant global importance as a water body with a delicate ecological balance. Given the sensitivity of the Persian Gulf and the detrimental impacts it endures from diverse polluting industries, environmental monitoring of this region is essential. This study presents a comprehensive analysis of geochemical changes, origin, and environmental and ecological risk assessment of potentially toxic elements in 140 sediment samples collected from the Iranian waters of the northeastern Persian Gulf.

We examined 140 surface sediment samples collected from varying depths of the waters under Iran's jurisdiction in the northeastern Persian Gulf during the MG-PG-2008 cruise. Our goal was to assess the level of contamination and ecological risk posed by elements such as As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn. The concentrations of these elements in the sediment samples were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to provide a comprehensive understanding of their presence. Additionally, we quantified the pollution intensity in the sediments using indicators such as the geo-accumulation index (Igeo), enrichment factor (EF), and modified degree of contamination (mCd). Furthermore, we evaluated the ecological risk of potentially toxic elements in the sediment samples based on the potential ecological risk index (RI) and determined the toxicity risk of trace elements using the toxic risk index (TRI).

The sediment samples indicate significant enrichment of elements such as As, Cd, and Mo. Elements like Fe, Pb, Ni, Cr, and Mn fall into the medium enrichment category, while Cu, Zn, Ba, V, and Co are classified as having low enrichment. Comparatively, Fe, Ba, V, Zn, Pb, and Cu in the sediment samples show lower concentrations than their corresponding values in the upper continental crust. The enrichment factor (EF) values for these elements are less than 1.5, suggesting a terrestrial source for these elements. Additionally, the modified degree of pollution (mCd) values indicate very low levels of pollution at almost all stations.The ecological risk evaluation of potentially toxic elements in the surface sediments of the northeastern Persian Gulf reveals that Cd poses a medium ecological risk, while other elements exhibit a low ecological risk. The overall average ecological risk potential index (RI) at all sampling stations indicates a low level of ecological risk. Cd has the greatest influence on the ecological risk potential index, accounting for 61% of the total index, followed by As with 27%. The average toxicity risk index (TRI) suggests no toxicity risk, with Nickel being the most influential, contributing 52%, while Chromium has a 19% share.Notably, the significant enrichment of As and Cd in the northeastern Persian Gulf suggests their predominantly anthropogenic origin. This high concentration of arsenic may stem from the release of wastewater from urban and agricultural sources, various industries, gas and oil fields, and dust particles. Likewise, the presence of cadmium can be attributed to sources like oil tankers' transportation and industrial wastewater from factories.The significant correlation between aluminum, nickel, chromium, and vanadium (Al, Ni, Cr, V) indicates their terrestrial origin, mainly attributed to riverside erosion, weathering, and atmospheric precipitation. While the average enrichment of chromium and nickel can be linked to their high natural concentrations in the soil of southern Iran, industrial processes, including oil refining, can also contribute to their sediment concentrations.

The ecological risk assessment indicates medium-level risk for cadmium and low-level risk for other elements. The overall average potential ecological risk index (RI) suggests a low level of ecological risk across all sampling stations. The average toxicity risk index (TRI) indicates no toxicity risk, with nickel contributing the largest share (52%) followed by chromium (19%). Chromium and nickel concentrations in sediments are primarily of geogenic origin, evidenced by their strong correlation with aluminum. The average enrichment of these elements is attributed to their high natural concentration in the soil of southern Iran, although some man-made sources also contribute. The significant enrichment of As and Cd in sediments suggests their predominant human origin, possibly from wastewater discharge, industrial activities, and oil and gas fields. Cadmium in the Persian Gulf may originate from anthropogenic sources such as oil tanker transportation and industrial wastewater discharge.

Qeshm Island, with an area of ​​1,486 square kilometers, is located at the southeastern end of the Zagros Belt and at the western end of the Strait of Hormuz. Since the tectonic era, it seems possible to assess the influence of neotectonics and fault dynamics on island morpho-tectonic deformation using basin tectonic indicators. In this research, five indicators are extracted and calculated using satellite images, geological maps, aerial photographs, and a digital elevation model (30 meters) using various software. The smoothness and asymmetry of waterways (AF), watershed shape index (BS), cross-topographic symmetry index (T), river meandering index (S) and their comprehensive evaluation are evaluated in model form (IAT)). It is an index to evaluate the degree of tectonic deformation in the basin, and the obtained results indicate the relative dynamics of various tectonic deformations on the island. Furthermore, based on the IAT index, 26 of the 44 subbasins belong to a very high tectonic layer, consistent with the number of faults, so more active tectonic deformation is observed in the western part of the island.

Geoscience studies in solving archaeological problems in the east of DamghanFathalizadeh Kosar1, Zarei Elahe2*, Sarfi Mehdi21Master of Science, School of Earth Sciences, Damghan University, Damghan, Iran2Assistant Professor, School of Earth Sciences, Damghan University, Damghan, IranCorresponding author (Elahe Zarei) E-mail: ezarei@du.ac.ir1- IntroductionThe results of archaeological investigations show the presence of humans in the northern part of the central desert of Iran since long ago (Vahdati nasab Hamed and Hashemi Milad 2016). The location of ancient settlements, as the settlements of previous humans, is mainly dependent on environmental factors such as water sources. Therefore, in order to determine the presence of water and its expansion, a 13 km long area was studied on the road from Damghan to Shahroud.2- Material and MethodsPalynology and sedimentology are common and applied methods for paleoenviroment interpertation especially for Neogene and Quaternary sediments. After the field studies, a number of samples were collected from 3 study stations to palynological, sedimentological and microfacies studies. The studied area is located on the border between Alborz structural state and Central Iran, approximately 30 km east of Damghan (coordinates with E 54° 36΄09 ˝ to 54° 45΄37˝ and N 36° 15΄43 ˝ to N 36° 16΄ 26 ˝).3- Results and discussion Geological studiesIn this research, XRD studies were used to identify the minerals in the region. Also, in order to check the degree of rounding and sorting of the sediments and to identify the mineralogical composition of the samples after sieving, they were studied under the streptomicroscope. The presence of transparent and angular quartzes and unstable minerals such as feldspar and muscovite and the abundance of organic matter in the landform sediments indicate an aquatic environment in which a series of erosion events to sedimentation have taken place in a short period of time. Based on the presence of some index dinoflagellate species such as Operculodinium cf. eiricianum and Bitectatodinium tepikiense and comparing it with the world standard biozones of Williams et al., 2004, the age range of Late Miocene to Pliocene can be considered for the landform sediments. (Head 1994).A combination of archaeological and geomorphological data, sedimentology and palynological studies and the presence of Index dinocysts such as Operculodinium cf. eiricianum and Bitectatodinium tepikiense indicate a vast and ancient lake during the Late Neogene (Brenchley1998, Head 1994, Michelle Price, 2010). The presence of ancient settlements confirms this claim.This relatively vast aqueous environment was related to the Haj Ali Qoli salt playa (Chah Jam playa) in the south of the studied area, and the sediments studied were placed on the northern edge of the lake when the water level was high. Probably, tectonics and climate have influenced the lowering of the water level. Butzer 1958 and Crinsley 1970 report evidence of a lacustrine environment around Central desert of Iran (Butzer, 1958; Krinsley, 1970).4- ConclusionThe most important issue for archaeologists in the last few decades is the investigation of environmental factors in the formation or destruction of civilizations and human habitats.One of the most important points for creating human settlements is the presence of water sources close to human settlements. Archaeological research indicates the presence of humans in Damghan region from the past until now. In this regard, the spatial distribution and dispersion of the ancient centers of eastern Damghan and its relationship with environmental factors (water and climate) were investigated. A combination of archaeological, geomorphological and palynological data shows that there was a vast paleolake in the Northern part of the Iranian Central Desert, which is considered a suitable environment for human settlements. The studied sediments were deposited on the clay zone in the northern margin of Damghan playa when the water level was high, which is probably related to Haj Ali Qoli salt lake (Chah Jam playa) in the south of the studied area. The high amount of clay 20 to 45% confirms this environment. The presence of an index dinocyst Bitectatodinium tepikiense shows that there was a paleolake in the northern part of the central Iranian plateau at the end of the Neogene, which was probably connected to the open sea. Probably, two factors, tectonics and climate changes, have influenced the lowering of the water level and made it into its present form.Key words: geological studies, ancient lake, ancient settlements, East DamghanReference:- Butzer, K. W. 1958. Quaternary Stratigraphy and climate in the near East, Bonner Geogr.Abhendi, 24.- Brenchley, P. J. & Harper, A. T. 1998. Palaeoecology: Ecosystems, Environments and Evolution, 402 pp. Chapman & Hall publ, New York.- Head, M.J., 1994. A forum on Neogene and Quaternary dinoflagellate cysts. The edited transcript of a round table discussion held at the Third Workshop on Neogene and Quaternary dinoflagellates, with taxonomic appendix. Palynology, v.17, p.201-239, pl.1-11. (Cover date 1993, issue date 1994 - 28th January).- Krinsley, D.B., 1970.A geomorphological and paleoclimatological study of the playa of Iran. U.S. Government printing office Washington D.C. 20, 402p.- Michelle Price Andrea. 2010. Late Quaternary climate and oceanographic changes in the Northest Pacific as recorded by dinoflagellate cysts from Guaymas Basin, Gulf of California (Mexico).Master of Science in the school of Earth and Ocean Sciences. -Vahdati nasab Hamed, Hashemi Milad. 2016. Playa and Middle Paleolithic settlement of Iranian central Desert: the discovery of the Chah-e Jam middle Paleolithic site.Quaternary international 408(2016) 140-152.- Williams G. L. Brinkhuis H. Pearce M. A. Fensome R. A. and Weegink J. W. 2004. Southern Ocean and global dinoflagellate cyst events Compared: Index events for the Late Cretaceous-Neogene. Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 189.pp. 1-98

Tehran is known as the most important political-economic and demographic center of Iran. The rock fall as a natural hazard has always caused a lot of damage in this City. Therfore, identifying the factors that are effective in the occurrence of this phenomenon is very important. In most cases, the danger caused by falling rocks cannot be avoided. Because the spatial and temporal variation of this phenomenon is very high. The main goal of the current research is to investigate the parameters involved in the rock fall in Tehran province.

The rock engineering system is an analytical method that prepares a model to studying the problem and analyzing its variables. The main tool of this method is the interaction matrix. This matrix makes the effect of all parameters on the system and the effect of the system on the parameters to be studied. Numerical and analytical models are only able to model a part of the interaction between different parameters, but this method is able to model a complete system. Due to the cause and effect nature of these interactions, the system has a dynamic state, which means that a change in a parameter can decrease the value of that parameter in a chain process. These changes occur until the system reaches equilibrium. In order to prepare a rock fall potential map, it is necessary to take help from 7 different layers, including the slope, relative relief, rainfall distribution, vegetation, seismicity, weathering and rock blocking. Therefore, first of all, the mentioned maps are classified separately. Then, it is necessary to prepare a map of rock fall potential by giving weight to each of the layers. In this research, the rock engineering system method was used to weight the above parameters.

In this study, the rock fall potential map was prepared by using 7 layers of information and weighting each one according to the rock engineering system. This map shows a well-defined relationship between mountainous areas and increased risk of rock falls. Also, in the location of the main faults, a significant increase in the hazard of rock fall can be seen. The increase in topographic slope can be considered effective in the changes in the hazard of rock falls. In general, since rock fall potential is prepared based on 7 data layers, each of these layers is effective in changing the hazard level. It should be noted that the role of faults has been properly considered in two ways, one in the amount of rock crushing or blocking and the other in earthquake acceleration. The location of landslides and slope instabilities was also compared with the hazard map of rock fall. Based on this, it was found that all these positions are located in areas with very high to high risk. This case confirms the accuracy of the present analysis to some extent. The results of this research are used to indicate areas at risk.

 Conclusion:

In most of the studies related to rock falls, the main goal is to reduce the risk of this phenomenon. To reduce the risk of rock fall, the dominant mechanism should be identified and then the risk of this phenomenon should be reduced by explaining the important factor with corrective measures. One of the methods used to reduce the rock fall hazard is to reduce the hazard elements in the rock fall area. Also, in many cases, it is not possible to reduce the risk elements and some protective structures, and corrective measures must be taken to protect the risk elements from falling blocks. For efficient facility design, some characteristics of the fallen blocks should be available to help designers make decisions about facility location and capacity.