نشریه کواترنری ایران
پیاپی 12 (زمستان 1396)

Deltas are the most dynamic geomorphological landforms which simultaneously affected by the sea and land processes. A brief survey shows rising and falling of Persian Gulf level water and coastline displacement have been created changes in the boundary of the Arvand Delta distal and The edge of the continental shelf. Arvand delta as the largest delta of Persian Gulf, due to its very low slope in foreshore and the effect of eustatic changes of Persian Gulf and river sedimentation has experienced many changes during the last period of the Quaternary to the present– from applied geomorphology point of view so far has not been studied. The importance of this issue becomes twofold when we know coastal changes are rapidly increasing under the influence of global warming in recent years and the need to investigate the response of coastline against to this approach is inevitable. Therefore, the aim of this study is to achieve the changes and evolution of the Arvand delta during Holocene. In order to achieve the purpose of the research, survey - laboratory instruments and digital - documentary data were used as follows: study of books, articles, dissertations, research projects for general realizing of the subject and case study, area geomorphological map in order to evaluating the now morphological situation and selecting the points of coring, granulometry analysis of 47 sedimentary samples from 7cores (a total of 56 m drilling) in order to detect the size particle above 63 microns using  wet sieve shakers and smaller than 63 microns using a laser particle sizer, elemental analysis of 47 sediment samples using inductively coupled plasma method using ICP-OES, mineralogy of 47 sedimentary samples using X-ray diffraction (XRD), dating radiocarbon Using the mass spectrometer accelerator method at Beta Analytic Radiocarbon Dating Laboratory, Florida, USA and finally, the separation and reconstruction of sedimentary environments associated with sea level fluctuations. Separation of sedimentary environments initially was carried out and 3 sedimentary environments from up to down were identified. The variation and sequence of sedimentary environments from the fluvial to the marine is in 3 meters depth on average. Granulometry analysis of 47 sedimentary samples shows study of granulometery cannot correctly do the analysis the sedimentation processes of delta. Elemental analysis of samples shows the amounts of aluminum, chromium, manganese and barium (terrigenous origin) are inversely related to the changes in sea level in this region. Also, change trend in the elements of calcium and strontium (ocean basin) conforms to sea level changes trend. Mineralogy results of samples showed due to the crossing of major rivers flowing to the Arvand delta, especially Karun river from carbonate formations in the Zagros mountains and the geographic location of the Persian Gulf in the semi-tropical climate, the amount of calcium carbonate in the form of calcite, dolomite and aragonite is more than 50% of the total amount of sediment. Evaluation of the dating results after calibration of samples and depth - age graph in the core MR.7 (the southernmost core in the delta distal) shows the average of delta sedimentation rate has been 2.9 mm / yr in 2500 years ago. Sediments of seven cores in Arvand Delta (Iranian part) using sedimentary evidence not only reveals features of sedimentary environments during sedimentation, but also can be indicative of fluctuations, deceleration and transgression of sea level. The results of sedimentary paleoenvironments reconstruction and delta morphogenesis processes in relation to Persian Gulf sea level changes, from up to down, respectively 3 sedimentary environments identified: fluvial plain, brackish–freshwater marsh and marine (tidal). Geochemical analysis (elemental and mineralogy analysis) of sedimentary samples compared to Granulometry analysis can be show better determine the relationship between sea-level changes with delta progressing in this area. Results of carbon isotope analysis (in order to time reconstruction of sedimentation process) and the isotope of oxygen (in order to reconstruction of past climatic conditions) along with other previous studies (Aqraw, 2001; Bogemans et al, 2016, 2017; Heyvaert and Baeteman, 2007; Lambeck, 1996; Purser, 1973; Sanlaville, 2002 and Shahbazi, 2016) showed Arvand delta due to the interference of active fluvial processes (about 2300 years ago) with progradation and transgression of sea (about 9,000 to 2300 years ago) is formed. Arvand River about 2,300 years ago when the weather was colder than present (-2 /75 °) in response to gradual dropping of sea level had tried to reach itself to the lower basic factorerect factor level (Persian Gulf) with the rate of 3/19 mm/yr.

 The impact of past processes on development of Qazvin and Eshtehard plains is quite visible in the region’s landforms. Being the function of geological structure, tectonic movements and geomorphological processes, these effects have shaped the geomorphology of the region in a way that Eshtehard plain forms a saline depression with a gentle slope entering from the south into another hole via Shoor River that reaches the end of Mahdasht alluvial fan. In the middle of this depression, parallel hills can be seen drawn from west to the east. The existence of eroding loose hills in a low slope area covered in evaporite sediments and water stroke in southern hole, has formed the geomorphic features of the region in a way that is not justified with the current situation. Researchers who have studied this region, have achieved different results. Sadough et al (1396) have concluded thattectonic movements caused by Eshtehard Fault and the development of Mahdasht alluvial fan, have changed Shoor River’s direction towards south. Ramesht et al (1393) have concluded that there has been a paleo-lake behind Mahdasht Alluvial fan and its overflow, has caused the lake to tear through Mega-Floods. It seems that to explain the paleo-geomorphology of the area the evidence of the upstream location of these events should be investigated with a wider look to the region. Resources used in this research, include two categories of documentary and library sources including articles, books, sites, theses, all written resources and field data including field visit, sampling and investigating geomorphological evidence. The tools used in this research include two groups as well. Physical instruments like maps, diagrams, laboratory tools and field sampling equipment, conceptual tools such as ArcGIS software, GRADISTAT, Google Earth and etc. First, geomorphology map of the area was created and the history of past processes was identified. Then landforms of area were sampled. Samples were transferred to the laboratory in order for some experiments to be done, such as granulometry for extracting statistical parameters of sediments, morphoscopy to identify the amount of rounding, origin and sedimentation process, hydrometry for indentifying particle diameter in silt and clay size. At the end by connecting the results, the evolution process of Qazvin and Eshtehard Plains, was explained. The results showed that the existence of stretched and fine-grained hills in the north of Qazvin Plain and Eshtehard, represents a relatively stable environment in the past and cutting it down by water-ways, shows a change in situation from sedimentary environment to erosion environment. Earth’s current surface in the area is lower than the past sedimentary floor and the little difference between the heads of northern and southern hills indicates that there has been a paleo-lake in this region with an insignificant slope from north to the south. Forming alluvial terraces in south-western part of the basincould be related with changing the river base level, in addition to climate change. This is because the reverse and gentle slope of sedimentary layers indicates a very slow tectonic movements in southern mountains. Because of that, forming of terraces in relation with baseline changes could be considered as sign of descending in lake level in the current location of Qazvin Plain. The sign of water in the southern slopes of halghedar anticline are seen like significant water strokes. The existence of clay hills in Qazvin Plain and waterstrokes in Eshtehard Plain indicate that full opening of the lake which has been situated in the north of halghedar hills, has occurred in transition from glacier to inter-glacier. Buried sand hills and gypsum crystallized particles among the sediments confirms the existence of an evaporate environment  in the studied area. The obtained sedimentary evidence indicates periodicity of high and low water courses in a closed sediment basin. These evidence include layered fine grained deposits, also layers with coarser sediments, evidence of the formation of sand dunes in the region and the presence of crystalline particles of salt and gypsum among the sediments. Terraces of Kharroud River in  southwestern part of the basin show the change in base level. Loose and parallel clay hills, can prove that these sediments have been deposited in a calm and closed area. Water strokes in southern slope of Halghedar anticline shows the sudden exit of water from the area and the formation of a lake in the southern depression. Thus, the results of this study proves the existence of a lake in Qazvin plain in the last glacial period and shows that in transition from glacier to inter-glacier period, as the ice melted in heights and mega-floods occurred, the  lake’s water level rised and overflowed from the southern heights, and meanwhile a part of anticline eroded. This causes a reduction in depth of the lake and in inter-glacier period, when the weather was much warmer, evaporation created playa environment in the lake and this happened frequently until the front of lake is completely open in the last period of transition from glacier to inter-glacier.

The Zagros range extends for 1500 km from southeastern Turkey to Hormuz Strait and Persian Gulf. This active fold and thrust belt is composed of deformed sediments of the Arabian margin and has grown since Early-Middle Eocene in response to convergence and ongoing collision between Arabia and Eurasia plates. Crustal shortening in the Zagros is expressed by active folding and thrusting associated with a widely distributed shallow seismicity (depth < 20 km). The Dorud fault with general trend of NW-SE has known as one of the most important seismic in segments of Zagros Main Recent fault, near the Arjng area.In this study we use morphotectonic evidences to show that seismic behavior of this fault in the past has a clustering model in some time intervals. Geomorphic indicators are used as a tool to identify recent structures and movements. However, prior study of the region and the presence of high magnitude earthquakes that destroyed 100% of the villages with a 1 meter vertical displacement of the area indicate high tectonic activity. For this purpose at the first near-field morphotectonical analysis performed using Real Time Kinematics (RTK) GPS survey, digital elevation model and digital topographic map with high accuracy of surface ruptures of past earthquake prepared. To calculate the amount of displacement on the fault plane after applying the software steps on the DEM in Surfer software, perpendicular to the strike of the fault. These two lines extend the tangent to break the fault. The distance between the two points that cut two tangent lines indicates the amount of vertical displacement on the earth's surface. Digital elevation model and digital topographic map with high accuracy from the level of ruptures created from these findings were used to determine the quaternary fault of Dorud. Also, the geophysical studies of this part of the Dorud Fault after the preliminary studies of geology and the investigation of the probable extension of the fault using a special bipolar resistivity method (bipolar- bipolar) with a profile of 10 meters in 10 meters of two profiles were used. After the final processing and modeling the resilience data in Res2dinv software, the cesium magnetometric scanning was carried out on 4, 160-meter profiles.  According the results calculated for 3 stations amounts displacement respectively: The horizontal cumulative displacement on the fault surface is 21.59, 10.05, and 13.94, the vertical displacement of the vertical side on the fault surface is calculated 58.6, 57.5 and 13.47 and the net cumulative displacement is measured 22.88, 11.49 and 40/19. In order to investigate the fault mechanisms, the rake angles were calculated of the fault respectively as 17, 29 and 44 degrees. According to the results, the fault has a dip- slip component. Geoelectric impressions using a bipolar and bipolar arrangement on 2 the highest for the apparent resistivity of 101.7 and the least value 7.2 mm. Geo-electric resistivity measurements with CRP arrangement with the characteristics of OA = 50m and MN = 20m included two profiles with 70 points and a total of 145 points. In order to determine the lateral changes of the ground resistance, CRP resistivity measurements with OA = 50m and MN = 20m profiles on 0 profiles containing 33 points and profiles 80 including 37 points were performed, the highest value for the specific strength of 135 the least value is 13 ohm-meter. Investigation was done by magnetization on four profiles of 0, 40, 80 and 100 consecutive (Continue) with linear 0.64m. Geophysical studies on faults Dorud, the resistivity data acquisition with dipole-dipole array and 10 and 10 meter electrode spacing. After final data processing and inversion of resistivity data in Res2dinv software, cesium magnetometery survey on 4 profiles 160 metric. After the completion of field operations and data question clearer interpretation of the subsurface structures, especially faults and discontinuities in the study area were obtained. The Dorud fault in this site is characterized by three fault lines, which is to say that the F'4 fault, according to morphotectonic studies, has been made as the main Drood fault and the rest as faults parallel to it.There are three possible fault symbols F'3, F'4 and F'5 in the region showed that there can be prepared a series of fault according to the geological map of the studied area is confirmed. The main fault as the fault F'4 Dorud and other faults are parallel to it. All branches of the fault are partly in parallel with stepped-up right and left Stairs in some places just to releasing bend small landslides were observed in the region and in the region just too restraining bend with compression strike- slip duplex.

In arid and semi-arid regions, due to low rainfall and overexploitation of groundwater resources, and subsequent saltwater intrusion, the available fresh sources are reduced. Hydrological study and water budget are the first steps in identifying and assessing the region's water potential to provide management plans for the preservation of the fresh water aquifer. Recently Groundwater is becoming increasingly important as a source of drinking water, agriculture and industry activity. More than a hundred countries are facing water shortage of varying severity in the world. About 40% of the global population is situated in heavily water deficit basins. Estimating the terrestrial water balance is one of the main scopes of hydrology. Access to good quality of drinking water is the most basic of human needs, but these conditions are not always available in many of the arid and semi-arid regions. Arid regions are particularly sensitive to variability induced from climate changes. Investigation of water budget variables, such as precipitation (P), evapotranspiration (ET), stream flow and terrestrial water storage (TWS), provides improved understanding of water resources under a changing climate system. The Geysoor Plain is situated in the semi-arid region of Khorasan Razavi Province in the East of Iran. The area of the aquifer in Geysoor Plain is 11784 km2. The Salty plain exists in the northwest of the study area. Geysoor aquifer is located in Quaternary alluvial deposits and clay basins. The Geysoor plain is located in arid with hot and dry summers and cool winters, and has a low sporadic rainfall from 100 to 120 mm for each year, and this precipitation is the main recharge source of the groundwater in this area. This research investigates the hydrogeology and water budget of groundwater resources in this area.   To investigate the hydrological setting of the plain, the iso-potential map of the area was drawn using the data of 18 piezometer wells. Then, all of the water budget components including inputs (sub-surface flow, direct precipitation etc.) and outputs (groundwater flow, harvesting of wells, etc.) were calculated for a year.   The data from water level variations in 18 piezometer wells are used to study the hydrogeological properties. The aquifer is mainly recharged from south, southwest, and northwest and discharged toward the northeast of the plain. According to the iso potential map, the general groundwater flow direction is from west and south toward the northeast of the Geysoor plain. According to the EC map, the electrical conductivity is consistent with the direction of groundwater flow, so that in the southern and northwest parts of the area, the lowest EC value is measured at 989 µS/cm. The highest EC was observed in the central areas of the plain, with a value of about 16800 µS/cm, indicating an intrusion of salt water from salt plain. Based on long term drawdown of water level, the Geysoor plain is divided into three zones. Geysoor plain with negative groundwater balance, showed an average storage reduction of 4.12 Mm3 per year. This in result of a considerable groundwater level decrease of about 5.38 m during a 24-year period. Decreases in recharge and overexploitation could cause progressive depletion of the groundwater resources and more budget deficits.     Hydrogeological investigation is as the first step in identifying and assessing the water volume storage to provide management plans for the protection of available fresh water. In the study area, piezometric water level data and chemical features of the groundwater samples from the alluvial aquifer in the Geysoor plain were measured to assess the hydrogeological condition, groundwater balance and hydrochemistry characteristics of the aquifer. The decline of the piezometric heads in the study area is indicative of an imbalance between recharge and extraction of groundwater and points to the necessity for restriction on groundwater extraction from these aquifer systems to avoid adverse effects. The Geysoor Plain with a negative groundwater balance showed a considerable reduction in the groundwater level. Therefore, the overexploitation of the wells and consequent change in hydrologic regime is the main etiologic factor of the groundwater quality degradation in the central part of the plain. Along the direction of groundwater flow towards the outlet of the plain, the salinity has been reduced due to recharging by carbonate formation in the eastern regions. This detailed investigation is of a particular importance for sustainable management of these groundwater resources, especially in arid zones coupled with increasing exploitation for irrigation and domestic water supply which requires immediate attention.

There are well exposures of Quaternary sediments along the beside of Zanjanrud river, west Zanjan province, northwest Iran. The Zanjanrud river watershed is restricted by two northwest-southeast trend mountain ranges: The Soltanieh Mountains in the south and Tarom Mountains in the north. The Quaternary sediments were divided as the terrace and alluvial units in the previously studies. Here, we survived these sediments in the stratigraphic viewpoint, and for dividing theminto lithostratigraphic units with age determination.    Zanjanrud watershed is 120 km in long and 60-70 km in width, which terminates to Qezel Ozan river in the northwest Zanjan. Seventeen sections were surveyed for evaluating and distinguishing the lithostratigraphic units, with studies of sedimentological characteristics, paleontological features and architectural elements of the sediments. 16 sections were survived besides the Zanjan-Tabriz highways from toll station to Mahneshan cross-road, located in the 40 Km distance. The good exposures of sediments are available in the tranches in both sides of the highway. The last section (seventeenth section) studied in the eight kilometers of Zanjan’s airport highway. The thickness of surveyed sections differ from 5 m, in section number 14 to 26.4 m, in section number 12. The Quaternary deposits of the west of Zanjan overlay on the colored Plio-Pleistocene marls as an erosional unconformity and their upper boundary is erosional surface. Provenance of particles of sediments is considerable from Tarom and Soltanieh mountains. Tarom Mountains comprise volcaniclastic sediments of Karaj Formation, Eocene in age. Soltanieh Mountains, however, includes diverse rock units from Precambrian to Eocene. The rock units of Soltanieh Mountains are Kahar, Bayandor formations (Precambrian), Soltanieh, Barut, Zagon, Lalun and Mila formations (Cambrian), Dorud and Ruteh formations (Permian). Mesozoic rock units are scarce as Shemshak, Dalichai and Lar formations (Jurassic). Fajan, Ziyarat, and Karaj formations are rock units of Cenozoic and are Paleocene to Eocene in age.   Five lithostratigraphic units have been identified which include coarsening upward sequence as following as: Upper boundary; erosion surface. Unit (e), eroded mud-supported gravel, cream to green in colure. Unit (d), light colored and thick-bedded coarse-grained gravels with brown to purple mud intercalations, and finally. Unit (c), regular alternations of light brown to cream mud, sand, and gravels. Unit (b), gray to violet and moderate to well-sorted sand and fine-grained gravels with cross-bedding and sparse cream mud, sand and gravel intercalations. Unit (a), alternations of dark to light brown muds with thin sand and fine-grained gravel intercalations. Lower boundary; concordance with Plio-Pleistocene colored marls. Sedimentology studies of the 176 sampled specimens show particle mean size variations as 1.80 to 2.91 ɸ, with statistical analysis as very poorly sorted, strongly coarse-grained skewed, near symmetrical and fine skewed, and platykurtic to mesokurticin the textural parameters. Heavy minerals of the 16 sampled specimens include Apatite, Anatase, Epidote, Sphen, Ilmenite, Barite, Titanomagentite, Rutile, Zircon, Limonite, Amphibole group, Pyroxene group, Magnetite and Hematite as main heavy minerals. Sphalerite, Biotite, Pyrite, Chalcopyrite, Garnet, Jarosite and Leucoxene are secondary heavy minerals in these samples. The frequency of main heavy minerals shows sinus variations in the scrolling distance and secondary heavy minerals frequency, however, are linear in the distribution in this distance. Architectural elements of the studied sections include five gravel facies (Gm, Gms, Gp, Gt, Gh), four sandstone facies (Sm, Sp, St, Sh), two mudstone facies (Fm, Fl), and a calcareous facies (p). In the studied sections, any significant body fossils were found, and only single trace fossil, Skolithos, was observed. According to the stratigraphic position, the age of the studied sections attributable to Pleistocene to Holocene.  Quaternary sediments of Zanjanrud watershed in the west of Zanjan, include coarse-grained gravel, sands, silt and clay deposits. The thickness of sediments varies from 5 to 24 meters. Five distinctive lithostratigraphic units are distinguishable as coarsening upward sequence. The lower part of the sequence includes dark to light brown muds with thin sand and fine-grained gravel intercalations, gradually sand size sediments increase in upper parts. The alternations of mud-gravel layers are well developed in the mid parts of the studied sequence. Uppermost layers of sequences comprise thick bedded coarse-grained matrix-supported gravels. No macrofossils were found in the studied section, and they are Pleistocene to Holocene in age at all. It seems that studied sediments deposited in the Alluvial fan system, which was fault controlled environment between Soltanieh and Tarom mountains.

 The area of study in this paper is located at the Northern fringes of Iranian Central Desert (NICD). Regarding its vast size, only the Paleolithic sites located in modern Semnan province are included in this paper. These sites are Mirak, Delazian, Soufi Abad, and Chah-e Jam, containing evidence of human presence during the Last Glacial Cycle (LGC; circa. 116-11.5 kya). The information surrounding the evolution of cultures in the Central Plateau of Iran during the Late Pleistocene is meagre. Moreover, its climatic-environmental fluctuations have not been studied throughout the mentioned stage. Therefore, running an investigation into data recovered from the Paleolithic sites have not been possible in the absence of climatic information so far. This paper, written based on a couple of field expeditions conducted in the NICD, is one of the first attempts to analyze the Paleolithic archaeological finds based on the Pleistocene climatic-environmental data in the area. The case study is Mirak; a Paleolithic site located about 8km south of the modern city of Semnan. The site is comprised of 8 mounds, of which the mound no. 8 was selected for the excavation. The mound itself is of aeolian origin which has been formed throughout Holocene and is responsible for the covering of the Late Pleistocene deposits. Regarding the huge scatters of stone tools and the absence of cultural layers in the landscape, it is logical to assume that the aeolian mound has conserved archaeological deposits beneath. Contrary to the mound, Pleistocene cultural deposits were formed under alluvial regime in a floodplain during a period of relatively cold and humid. In addition, contemporaneous to the terminal Pleistocene, a hiatus of some millennia divided the alluvial sequence from the topmost Holocene sediments, ending the Paleolithic occupation of Mirak. At least, three Paleolithic cultural layers are identified in this site. The Methodology of this research is combining information from multidisciplinary analyses conducted in Mirak, and then, presenting some preliminary explanations in the framework of Human Behavioral Ecology (HBE). In doing so, in the framework of PhD dissertation of the corresponding author, data gained from lithic and faunal analysis, sedimentology, geomorphology, granulometry, micromorphology, mineralogy, and absolute chronology were combined. Moreover, the bibliographic resources regarding the climatic-environmental fluctuations in a regional scale (Iranian Plateau and the Asian Southwest) were added to the excavation data to check the probable correlations. The sedimentological evidence of Mirak indicates frequent water table and humidity fluctuations throughout the Pleistocene, which probably is comparable to the known millennial-scale climatic fluctuations during the LGC (Dansgaard-Oeschger or D-O events). The subsequent changes in floral/faunal composition in response to such fluctuations in the region are presumable. The evidence of teleconnection between Late Pleistocene Greenland (D-O events) and continental Asia has been indicated based on the Chinese Loess Plateau, the eastern part of Central Asia, Northern Iranian Loess, and the western part of Dasht-i Kavir. Such teleconnection may further affirm the claimed relationship between continental-scale climatic fluctuation and local evolution of climate-environment throughout the NICD. The LGC is generally considered a cold and dry period on continental scale. As a result, the fragmentation of landscapes is expected in continental regions such as the NICD. Therefore, using the data recovered from the fieldworks conducted in the region plus bibliographic investigation on the climatic records on regional and continental scales, one could preliminarily deduce the paleoenvironmental characteristics of the NICD, the timeframe during which human occupied the region, and some other mobility- and subsistence-related features. Based on characteristics such as the presence of Levallois-Mousterian flake-based assemblage in company with prismatic laminar products, the archaeological deposits of Mirak could be placed in the second half of the late Pleistocene, MIS 3 in particular. Thus, from the archaeological point of view, Mirak belongs to the Late Middle and Upper Paleolithic periods. The results of OSL and post-IR IRSL datings confirm this claim, as well. In combining lithic and environmental data in the framework of Ecology, it is suggested that logistical mobility in Mirak was high and the site was probably a central place in its own right. Moreover, the presence of human groups was frequent but discontinuous. Based on similarities between Mirak and the three other mentioned archaeological sites, such results could likely be claimed for them, as well. Presumably, none of the archeological sites represents continuous presence of hunter-gatherers during the Late Pleistocene. Finally, it seems the NICD roleplayed both as a corridor for the expansion of human range and a magnet for living throughout the later part of Late Pleistocene.