Quaternary Journal of Iran

Abstract Saymarreh landslide, as the largest landslide in the world, has resulted in the formation of successive dam lakes in the several stages in the late quaternary. The distribution of archaeological sites on sediments deposited in these lakes, geomorphological and geoarchaeological evidence show a significant relationship between the development of civilization and paleogemorphological events of the region. The purpose of this research is to determine and analyze the relationship between the development and decline of civilization with the Paleogeomorphology and paleoenvironmental changes. The research method is experimental based on the field and laboratory data. Field studies were carried out on the lakes sediments, excavation of trenches and location-selection of human habitats. In order to determine the formation time of the lakes and its definitive effects on the civilization, the two trenches were excavated within the ancient sites, then stratigraphy of the trenches was determined and a sampling was done. Several samples were analyzed, and four of them were dated by OSL dating method. The results of field and laboratory studies indicate that the several successive lakes had been formed after the Saymarreh landslide occurrence in the region, and the late quaternary especially the Holocene epoch can be divided into lake and inter-lake periods. The three lake periods (6460, 3110, and 570 years ago, respectively) coincided with the historical periods of human habitation and the development of civilization in the region. The development of civilization and the increase of human settlements coincided with the inter-lake periods, and the decline of civilization, the destruction of human settlements and cultural transfer coincided with the lake periods. Changes and fluctuations in the human habitation trends in the region had been influenced by the lake periods and, conversely, these changes prove the occurrence of lake periods during the Holocene. Generally, the formation of successive lake periods as a geomorphic factor played the most important role in the development and decline of civilization in the Saymarreh region during the Holocene.

Abstract Antropogeomorphology is a new branch of geomorphology which investigates the role of human in changing landforms and the process of geomorphologic modification such as weathering, transport and deposition. Management and engineering related activities result in widespread changes in landscapes. Some landscapes such as terraces in arable lands, which are formed in farmlands and have completely different shapes, are the direct result of anthropogenic processes. Landforms produced by indirect anthropogenic process are not easily recognizable unless they are involved in the formation of natural processes. Such landforms are the result of environmental changes, which are brought about by human activities. One of the examples of such activities is the escalation in the rate of soil erosion due to over exploitation from forests. The main works done in this area include: Man and Nature(physical geography as modified by human action) by Marsh(1864), Man as a Geological Agent(1922), by Sherlock, The Human Impact(1981) by Goudie and Man as a Geological Agent by Nir(1983). Based on many studies about antropogeomorphology, the main fields are: mining, agriculture, settlements, water management, traffic, tourism, sports and industrial impacts on landforms.  
 
Material and Methods
The methods used in antropogeomorphology include: historical, socioeconomic and geomorphological approaches. In this paper socioeconomic behavior, Degree of Development (DD) and Degree of Perception (DP) on rate of geomorphological process investigated. On this basis, in Index of Potential Anthropic Geomorphology (I), the percentage of urban population and percentage of illiteracies indicates degree of development and perception of people resp. The required data can be obtained from international statistical yearbooks. To calculate of effects of climate and topography, the constants Kc _and K_r are used. Values of these constants may range from 0.4 to 0.8, (climate) and from 0.2 to 0.8, (topography). (Table 2). According to equation 3, I index 31 selected countries calculated and presented in table 3.Then, I index of selected countries divided into three groups. The final map (fig 5) was drowning on this basis and finally analyzed. Easy of access to data is one of the benefits of Nir method.
 
Results and Discussions
Considering the fact that the rate of population growth is not a suitable factor in quantitative and qualitative assessments of human activities; therefore, antropo-geomorphologic potential equation (eq, 3) is introduced. Two important factors such as the degree of development (rate of human interface in environment) and human perception (human induced erosion) form this equation. Based on this formula, there is a direct relationship between the degree of development and environmental perception on the one hand and the rate of erosion on the other. For assessing the potentiality of antropogeomorphology, 31 countries from different continents were analyzed. The I index have a values between 0-1(Table 3).
 
Conclusions
Based on Nir (1983), classification of Index of Potential Anthropic Geomorphology (I), the results of calculations are presented in table 3. The potentiality of antropogeomorphology in developed and poor countries are different. Moreover, these calculations indicate in three interval times. In some countries for example Iran, Turkey, India and Greece, trend of I index were regressive.
- In countries such as Hungary, Thailand and Poland, I<0.30, the risk of human geomorphologic activities is low.
- In some countries for example USA, South Korea, Philippines, Bulgaria, United Kingdom and Iran, 0.30 ≤ I ≤ 0.49, the risk is not negligible and some management activities should be taken.
- Countries such as Algeria, Morocco, Chile and Nepal  have the highest I index, (I ≥ 0.50), considerable damage followed by antropogeomorphological process. Engineering appropriate and immediate should be taken in these countries.

Abstract The study of the past glaciers and its effects are the most important subjects of the quaternary period. The most important climatic evidence of  the quaternary is also in the mountains of Iran, especially in the Alborz, west and northwest of the country is glaciers and related landforms. Geomorphologic studies focusing on glacial and periglacial landforms allow us to get a better insight into the spatial diversity of present and past climates. The Chehelcheshmeh and Saral Mountains are among the coldest mountainous regions in the country.These regions during the quaternary period was mainly influenced by glacial processes. The aim of this study was to reconstruct the quaternary snowline and morphodynamic zones based on glacial evidence.
2-Materials and methods
Chehelcheshmeh and Saral Mountains are located 46 degrees, 28 minutes to 46 degrees and 58 minutes east longitude, and 35 degrees and 34 minutes to 36 degrees north latitude. The method of this research is analytical-descriptive and data collection method is library and field. The data used in this study includes aerial images, DEM, topographic maps and geological maps, and analysis tools including Arc Map version 10 and Gradistat version 4 software. In this research to recreate the glacier zone we used Wright and Porter methods. The permanent snowline in the Wright method is equivalent to an elevation of 60% of the cirques in the area above that height. For calculation of ELA in the method of cirque-floor altitudes, a mode has been used for classified data. For laboratory studies in this research, we used two granulometry and microscopic methods for three sediment samples. For granulometric Process, we used Seave analyzes for particle with a diameter of more than 2 mm and Laser analysis for sediment grains with a diameter of less than 2 mm. Then, based on laboratory studies and field observations (to better control and identify the landforms) and with the help of aerial imagery, the study of elevational digital model and the study of geomorphologic landforms was identified evidence of each of glacial and periglacial morphodynamic zones.
3-Results and discussion
In the survey of the study area, 25 glacier cirques were identified, some of which are well seen by the surrounding landforms. Distribution of glacier cirques showed that the glacier extent was down to 1280 meters high. In accordance with the Porter's cirque floor altitude, the final limit of the quaternary snowline was 2483 meters above sea level, which considering the active glacier valleys, glacial evidence was also seen below this elevation. In the field observations, it was found that glacial deposits are located in the Ghezel Ozan river and at a height of 1900 meters. To determine the sedimentation environment, the results of Laser and Sieve analysis on the samples showed that the studied area is affected by the processes of freezing and melting in a cold environment by preserving plant remains and heterogeneous distribution and particles bad sorting. Maintaining feldspar minerals is another result of laboratory work, which indicates severe mechanical erosion and very low chemical erosion in the study area. The lack of clay and colloidal sediments confirms this.The glacial and periglacial morphodynamic zones in this research were studied using their evidence that was identified many of the relevant landforms including Cirques, Glacial valleys, Tills, Erratic rocks, Solifluction lobes, Rock cracking , Moraines, Avalanches and  Rock steps.
4- Conclusion
Investigation of glacial and periglacial evidence showed that quaternary snowlines in the mountains of Chehelcheshmeh and Saral compared to the investigations carried out on the Alborz, Zagros and central iran mountains at lower altitudes. Different climate of Kurdistan mountains compared with other parts of Iran is one of the main reasons for the low elevation of snowline in the region, so that the minimum temperatures in the synoptic stations of Zarrineh Obato and Heazrkanian that located in two catchment basins in the cold seasons it is mostly critical and one of the coldest parts of the country. Sedimentological evidence and laboratory analysis also indicate a cold environment in the study area mainly influenced by snow melting processes and mechanical processes, in many instances, irregular arrangement and bad sorting are observed and coarse particles constitute the highest weight percent. In the study of field evidence, many landforms and processes were identified that, considering the distribution of glacial evidence in the present, lower boundary of the periglacial morphodynamic active zone was introduced the 2750 contour.

Abstract Introduction
Bat Guano and sediment deposition in caves have been used as an important source of information for reconstructing paleoenvironment and climate changes. Environmental conditions and climate have been mentioned as the most important factor in the economic-social change, migration and even the collapse and decline of civilizations (DeMenocal, 2001), although this is a global issue, some semi-arid regions of the world, similar to Southwest Asia, where water is a key source of civilized activity, it is more important (Kelley et al., 2015). In caves throughout the world, bats in sufficient populations produce copious amounts of fecal droppings (guano) reported at rates up to 10 cm/year (Hutchinson, 1950). These deposits have been used to examine palaeoenvironments reconstruction for example, the guano geochemical studies, speleothem and cave sediments for reconstruction of paleoenvironment reconstruction, including stable  isotopes  δ¹⁸O, δ¹³C, , δ¹⁵N  pollens and micro-charcoal radiocarbon age determination of guano, paleology and paleoecology, bat fossils (Forray et al., 2015,  Royer et al., 2015,  Wurster et al., 2017, Onac et al., 2015,  Stoetzel et al., 2016, Widga and Colburn, 2015, Campbell et al., 2017).
The purpose of this study was to reconstruct environmental change and climate change in Kurdistan province using multi-proxy data derived from  geochemical studies (LOI, Oxides, major and trace elements and statical data) derived from a precisely 14C-dated bat guano and cave sediment recovered from kolatarika Cave.
Materials and methods
Study site
Kolatarrika (mean dark cave) Cave, located in the Ghalojeh Village (Divandarreh city, Kurdistan province). The cave is located at 1910 m a.s.l. in a small karst area. Kolatarrika Cave develops in Oligo-Miocene limestones (Qom Formation), has a total length of 56 m, and no water flows along its passages.
Sampling
A 160-cm guano and sediment core were taken by manually pushing an aluminium tube into a vertical wall deposit in the main guano accumulation is located in the Bat Room towards the end of the cave. The core was sampled at 2 cm ± 2mm intervals for geochemical analysis (73 samples) Samples for 14C dating were collected at irregular intervals based on changes of the guano and sediment texture.
Chronology
Four accelerator mass spectrometry (AMS) 14C measurements on bulk guano and bulk sediment samples was obtained from the Poznan Radiocarbon Laboratory (Poland) (Goslar et al., 2004),. The AMS 14C dates were then calibrated into The calendar Year Anno Domini (Cal AD) and Before Present (Cal BP) using OxCal4.3.1 software (Ramsey et al., 2013) using the IntCal13 (Reimer et al., 2013) a calibration curve. In the current study, we established the age-depth models using The Bacon2.2 code (Blaauw, 2010, 2011, 2013) running in an R software environment (Team, 2010).
Geochemical analysis
X-ray fluorescence (XRF) method was used to determine the Major oxides,  trace elements and loss on ignition (LOI).
Statistical analysis
 Basic statistics including, Correlation coefficient, Cluster analysis, Principal Component Analysis was carried out by using the Paleontological Statistics software (Hammer et al., 2001).
Results and discussion
Based on the age-depth model supported by four AMS radiocarbon dates, the sediment layers (85-160 cm) deposited between 4399 yr cal BP and 5686 yr cal BP and the guano deposit (85-0 cm) accumulated between 4399 yr cal BP and the present. The results of statistical studies show that there is a positive correlation between LOI in guano layers with Na2O, MgO, K2O, MnO oxides and Cl, As, Cu, Ni, Pb, and Zn, indicating that these oxides and elements are biological and originated from guano and there is a negative correlation between LOI with SiO2, Al2O3, Fe2O3, CaO, TiO2, P2O5 oxides and Ba, S, Zr, Y, V, Rb elements, indicating that these elements originated either outside of the cave or weathered by surrounding environments.
In the sedimentation layers there is a positive correlation between SiO2, Al2O3, K2O, TiO2, Fe2O3, Ba, Co, Cr, Nb, Pb, Rb, Sr, V, Y, Zr, all of these elements and oxides Have a negative correlation with CaO.
The results of cluster analysis for guano layers show that the two groups of elements can be detected; in group1: (As, LOI, Pb, Cl, MnO, K2O, MgO, Na2O, Ni, Zn) and in group2: (Nb, S, CaO, Sr, Mo, Cu, Ce, Cr, Co, Fe2O3, SiO2, Rb, V, TiO2, Zr, Al2O3, Ba, Y, P2O5). The results of cluster analysis for sedimentary layers show that the two groups of elements can be detected; in the group1 (Mo, MnO, MgO, Zn, Cl, As, Na2O, CaO, P2O5 Ni, S, LOI) and in the group2: (Nb, Sr, Cu, Ce, Cr, Co, Fe2O3, SiO2, Rb, V, TiO2, Zr, Al2O3, Ba, Y, Pb, K2O).
Conclusion
The results of four AMS radiocarbon dates, The age of the sequence of sedimentary layers and bat guano in Kolatarika Cave shows between 1955 cal yr AD and 5686 cal yr BP. The result of this study shows that between 5513 and 5814 yr cal BP, the region had a warm and humid climate and warm and dry climate between 4400 and 5513 yr cal BP. The bats have been gradually settled in Kolatarika Cave with the improvement of the environmental conditions, that is, the increase in humidity and temperature around 4399 cal yr BP. The highest bat accumulation was from 608 to 1122 cal yr BP (828-1342 cal yr AD), linked to the medieval climate anomaly (MCA) or the medieval warm period (MWP), which peaked at 835 cal yr BP (1115 yr cal AD), it coincided with the Seljuq dynasty in Iran. This indicates that the area has a warm and humid climate during this period. After this period, about 380 to 191 yr cal BP, linked to the Little Ice Age period (LIA), the bat accumulation in the cave has gradually diminished due to the cold climate. The lowest accumulation was 291 yr cal BP (1659 yr cal AD), which indicates that the area has a cold and humid climate. This phase, also linked to the Maunder Minimum period when sunspots became exceedingly rare and it has coincided with the Safavid dynasty in Iran. After this period gradually increasing the bat accumulations in the cave when local temperatures increased. The results show that bat guano is a very useful archive for reconstructing paleoenvironments similar to other proxies (tree rings, ice cores, lake and river sediments, loess, and glacier evidence) and are valuable resources in areas where no other paleo proxies are available.

Abstract Aggregates' resistance to degradation caused by the crystallization of sodium sulfate mainly depends on their lithology. Nonetheless, aggregates' accumulation environments can also affect their weight loss induced by crystallization of sodium sulfate. The present study sought to examine weight loss among aggregates in rivers and colluvial areas. To this end, volcanic and sedimentary rocks were collected from Damavand and Direh, respectively. Lithological features have a profound impact on aggregates' resistance to degradation caused by sodium sulfate crystallization. Therefore, care was exercised to select river and colluvial areas with similar lithology or formation. 
2-Materials and methods
In line with ASTM D2216-1990, ASTM D2216-10, 1990, 10, and ASTM C 88-99a, the collected samples underwent tests of porosity, water absorption percentage, and weight loss due to soundness. In the sulfate soundness test, the samples were saturated and dried in 5 cycles, followed by measuring their weight loss with a particular sieve. In this standard, the chosen sieves do not follow a specific pattern, and a single sieve may be used to gauge weight loss of aggregates with various sizes. In this way, it is difficult to compare the degree of degradation among aggregates with different sizes. Thus, in order to measure weight loss, the lower limit sieve was used for each range of aggregate sizes.
In addition, the microcrack percentage of the collected samples was investigated. To study cracks in aggregates, samples with three different sizes (25-37.5, 19-25, and 12.5-16) were collected from rivers and colluvial areas. In total, 150 samples (50 for each aggregate size) were collected from Direh, while 300 samples were gathered from Damavand. For sampling, the aggregates were sieved and divided into four equal parts. Subsequently, one part was randomly selected for analysis (ASTM C 702-98, 2003). Cracks in aggregates, which were studied through naked eyes, were calculated based on the ratio of aggregates with cracks to the total number of aggregates.
3-Results and discussion
The results indicated that the degree of porosity, water absorption percentage, and microcrack percentage are higher in colluvial fans in comparison with rivers. This can be attributed to different lithological processes that dominate the two areas. In rivers, particles travel through long distances; hence, they are more likely to collide with each other and break down along the microcracks. This process results in a smaller number of cracks in aggregates from rivers. Moreover, the weathered areas at the surface of aggregates are removed through abrasion, hence their lower porosity and water absorption percentage. Conversely, in colluvial fans, particles mainly slide in large masses due to gravity. Since aggregates in colluvial fans do not travel through long distances and are exposed to less abrasion, they have a smaller degree of porosity, water absorption percentage, and microcrack percentage. The results of soundness test also revealed that aggregates in rivers experience smaller weight loss compared to the ones in colluvial areas. Aggregates’ weight loss is a function of their size. In river beds, like Direh, the degree of weight loss for aggregates that are 25-37.5 mm is only 5% as much as that of aggregates in colluvial areas. For the smallest size of aggregates (300-600 micron), the degree of weight loss for river aggregates is 38% as much as that for colluvial aggregates. The same situation holds true for aggregates from Damavand, though with smaller difference in the weight loss of river and colluvial aggregates. That is, the degrees of weight loss among big and small aggregates from rivers respectively are 21% and 65% as much as those of colluvial aggregates.
In rivers, a smaller weight loss is observed among bigger aggregates. In contrast, a direct relationship is detected between size and weight loss among aggregates from colluvial areas. Due to the small number of cracks in river aggregates, microcracks play an insignificant role in degradation caused by sodium sulfate crystallization. The surface to volume ratio is greater in small aggregates (in comparison with big aggregates), hence degradation caused by sodium sulfate crystallization takes place at a larger surface of aggregates. Thus, given the smaller surface to volume ratio, bigger aggregates experience less degradation. Colluvial aggregates have a larger number of microcracks, which constitute the main factor in degradation caused by sodium sulfate crystallization. The number of microcracks and the degree of degradation go up in bigger aggregates. In such aggregates, the effect of surface to volume ratio is much smaller than that of microcracks.
There is a significant difference in the weight loss of big aggregates from Damavand and Direh. In colluvial areas of Direh, weight loss increases by around 100% among bigger aggregates, while the same index for colluvial aggregates from Damavand is around 20%. This can be attributed to the smaller microcrack percentage of aggregates in Damavand.
4- Conclusion
The degree of porosity, water absorption percentage, and microcrack percentage are lower in river environments in comparison with colluvial ones, that can be attributed to the longer transportation and hence abrasion of sediments. The rate of weight loss due to soundness is lower in aggregates obtained from rivers compared to those obtained from colluvial environments. In river beds of Direh, the degree of weight loss for large aggregates (25-37.5 mm) is only 5% as much as that of aggregates in colluvial areas, whereas for small aggregates (300-600 micron), the degree of weight loss for river aggregates is 38% as much as that for colluvial aggregates. The same situation exists for aggregates of Damavand, but the difference is lower due to the lower microcrack percentage, so that degrees of weight loss among large and small aggregates from rivers are respectively 21% and 65% as much as those of colluvial aggregates

Abstract Introduction

Overall, authors apparently agree that several Quaternary climate changes occurred in Iran, also on the drier Iranian highlands. However, the timing and direction of changes have been a matter of dispute (Kehl, 2009, 13).The history of the quaternary evolution in Iran, is one of the important issues that have attracted the attention of many researchers over the past decades. Despite many studies on the nature of these changes, there are still many uncertainties about it. There are two main views about the Pleistocene climate in Iran, the First,  not only does not accept an increase in precipitation during the glacial periods, but also believes in its reduction from the present values. The second is believed to increase the precipitation on the inner frontier of the Iranian plateau and the highlands. Proponents of the second theory also are two groups. The first group, such as Scharlau, gives rise to a significant increase in rainfall and the other group slight increases (Ayvazi 2013). This study, based on the hypothesis that the conditions in Iran were cold and dry during glacial periods, according to the detailed researches carried out in Iran over the past few decades, as well as in the sub-Saharan Africa, Arabia and Mesopotamia in the Quaternary, intends to find a response for the origins of rainy periods comparatively. A vast area in Iran, along with the sub-Saharan Africa and the Arabian Peninsula, are parts of the dry belt of the planet. According to this fact, this research is based on the assumption that similar mechanisms have affected these regions in the past, and Iran's rainy periods are due to a similar mechanism that affected the sub-Saharan Africa, Arabia and Mesopotamia. Although, the evidences of these changes in the glacial and partly Holocene periods have been documented in Iran, there has not yet been a clear scenario for the mechanism of these changes in a broad sense.

Materials and Methods

In this research on the one hand, it has been attempted in an analytical way, using the significant studies that have been carried out over the past decades in relation to the quaternary and in particular the late quaternary changes in Iran, theories and evidences are described, and the mechanisms and framework of events in glacial and interglacial periods are given.
On the other hand, with a broader view of how the quaternary changes in the neighboring and distant areas, including the sub-Saharan Africa, the Arabian Peninsula, Oman and Mesopotamia, have also been examined. Thus, using the technique of comparison and reviewing existing theories and resources, including numerous books and articles, and establishing a reasonable relationship between the events in Iran and other geographic regions during the late quaternary (Pleistocene-Holocene transition), It has been attempted to determine the general framework of changes in the Iran, during glacial and interglacial periods. In this regard, while paying special attention to the humid conditions of the first half of the Holocene in different regions, including Iran, the possibility of occurrence of periods known as rainy periods or Iran's fluvial conditions in Holocene or in general in interglacial periods is discussed.

Results and discussion

The set of evidences, including glacial and palynology data, show that during the last glacial period, Iran had a cold and dry conditions. This coldness and dryness were due to the expansion of the Siberian High southward. This system, even today, also governs cold and dry conditions on the territory of Iran. The aridity during the Lateglacial, probably resulted from a combination of climatic factors. The Siberian anticyclone, which today blocks all but the deepest depressions, may have been too strong or too large for low-pressure systems to penetrate into the interior of the Near East. In addition to the southward displacement of the polar front and related storm tracks, the westerlies may also have been weaker. Cyclogenesis may have been inhibited by a weak temperature gradient, and colder temperatures over the Atlantic and Mediterranean may have prevented the incorporation of substantial amounts of moisture (Stevens et al.2001).
At the late Quaternary, the cold and dry conditions of the last glacial period turned into a warm and humid climate in Holocene. The mechanism of this event is related to the changes in Earth’s orbital parameters, which caused an increase in seasonal distribution of the insolation that affected much of the northern hemisphere including African Sahara, Arabia, Oman, India, Middle East, as well as Iran(Kutzbach., 1981;  Kutzbach and Guetter., 1986; Kutzbach and Otto-Bliesner., 1982;  DeMenocal and Tierney, 2012). Humid condition in Iran was due to reactivation of Westerlies and northward penetration of Indian Monsoon from early to mid-Holocene. 
 

Conclusion

In general, the geomorphic evidences, palynological data, climatic models, and archaeological data related to Iran and adjacent territories, indicate that during the last glacial period, Iran has had colder and drier conditions than today. Based on the evidences, the Indian monsoon since the beginning of Holocene, except for limited areas in the northeast, north, northwest, and parts of the west, has affected the country. In the first half of the Holocene, the monsoonal effects during summer, along with the influx of western low pressures in the cold season, led to a very humid condition, especially in the central, eastern, southern and southwestern regions of Iran throughout the year. Thus, the so called Iran’s rainy periods or fluvial periods which its different evidences have been documented, especially in the central regions, caused by these climatic systems.

Abstract This research is focused on study of hydrogeochemistry and brines evolution of Mighan and Hoz-e-Soltan Playas, based on studying brines and hydrogeochemistry evidences. Meyghan and Hoz-e-Soltan Playas as an intra-continental sedimentary basins, are located in Qom watershed, in central part of Iran. Both Playas are influenced by the volume of input groundwater, intermittent streams, precipitation and evaporation. In order to study the brines and their evolution process, 19 and 25 water samples were taken from center of Playas to the margins, respectively by digging holes. Physico-chemical parameters were measured in the site and geochemical analysis of brines was performed in laboratory.  In addition, 95 and 109 sediment samples were collected from Meighan and Hoz-e-Soltan playas, respectively by hand auger and their mineralogy and sedimentary characters were analyzed. Major cations of both Playas are Sodium, Chloride and Sulfate; dominant evaporative minerals are Calcite, Gypsum, Halite, Thernadite and Polyhalite. Hydrochemical studies of inlet waters of both Playas indicate that mole ratio is HCO₃ << Ca + Mg, which changes into Na-Cl-SO₄ type in Meyghan Playa and Na-Ca-(Mg)-Cl type in Hoz-e-Soltan Playa during the geochemical evolution and deposition of evaporate minerals.