QUATERNARY JOURNAL OF IRAN
Year:2015 | Volume:1 | Issue:1|Papers Count:8

Extended Abstract:Introduction: Geographical and natural potentials of Zagros and archaeological findings from the studies suggest that this cultural area has been used for human societies from pre-history to the present days. Many devastating earthquakes (872 AD Saymareh) and a lot of landslides in the Zagros caused severe environmental changes in this region: Landslide occurrence in Kabirkuh, blocking the Kashkan and Seymareh River. The subsequently formation of the Jaydar and Saymareh Lake are among the most important environmental changes in this region.

Extended Abstract:Introduction: Iranian plateau with its outstanding geographical and climatic conditions has been considered a key region in the study of Pleistocene human societies. So far numerous Paleolithic sites have been discovered throughout Iran; however, our knowledge concerning the Upper Paleolithic occupations was limited to Zagros region. The Upper Paleolithic occupations of northern Alborz Mountains and southern Caspian Sea has been remained unknown. In this context, the discovery of the open air site of Garmrud 2 by the French-Iranian Paleoanthropological Project (FIPP) in 2005 was a major breakthrough in case of filling the mentioned gaps between older Paleolithic materials and those of Mesolithic from the southeastern of the Caspian Sea (e.g., Komishan, Huto, Kamarband, Al Tepe).

Introduction: The research specifically examines the Quaternary magmatism of Kurdistan (Bijar) and its relationship with the region's tectonics. Due to parallelism with Zagros main fault and continental collision zone, it seems that such magmatism indicates continental collision zone as well. But the reason of this magmatism is not clear. However, there are examples in the world that can represent magmatism in this region continued even with 15 million years interval. Considering the breadth of the magma composition, thickness of the lithosphere can be an important parameter in understanding of magma petrogenesis. Reported thickness of the lithosphere in the study area is about 150-200 km. The thickness of lithosphere causes changes in the composition and chemistry of magma in the region. One of the points in this research is phase delay activing after the closure of Neotethys Ocean till Quaternary magmatism. Allen et al. (2013) provided a model for melting involving subduction and dewatering of sediment of Arabian passive margin beneath the Eurasian plate as a result of melting of the Eurasian lithosphere. In this study, it was necessary to consider more precisely these three reservoirs of magma in terms of petrography and chemistry and then rising of these magmas and its relation with Area’s tectonic. Observations show three sources of magma in different combinations and sometimes different chemistry. So, magmatism of Bijar can provide a good view of the processes that control the composition of the continental lithosphere.

Extended Abstracts:Introduction: Wind erosion is considered as the most important factor in degradation of Iran desert areas in Quaternary period and at the present time, 30 million hectares of surfaces are affected by the wind (Ahmadi and Feiznia, 1999: 429). Plains vast space, inadequacy or lack of vegetation, abundance of fine particles, looseness or detachedness of particles are some of the factors that have provided necessities for the wind to form interior plains (Alaei Taleghani, 2005: 295). Vegetation limits transportation of sediments by reducing wind speed. This action causes accumulation of wind sediments around vegetation and formation of Nebkha landscapes in result. In other words, Nebkha is the result of interaction between wind erosion and vegetation. Khalaf (1995: 275) argues that morphology of Nebkha is controlled by growth patterns of plant species to a large extent. Stallins (2006, 4) states that understanding of ecogeomorphological landscapes takes place by considering ecology and geomorphology processes and feedback between them. Therefore, the type of plant species forming the Nebkha and the connection among characteristics of plant ecology and Nebkha cones morphometry are the most important topics in Nebkha sediments morphology and systematic analyzes. This study tries to rely on quantitative characteristics in geomorphology. Also, relationships among factors of Nebkhas landscape will determine yielding Nebkhas. Since several factors are involved in Nebkha morphology, this study tries to investigate the importance of vegetation in the Nebkha morphology without changing some of the other factors. In other words, by selecting a limited area of study, climatic factors (wind, rain and ...), sedimentary factors (size, grading and ...) and time is assumed constant. Therefore, changes and communications made by performances of plant species forming Nebkha have investigated. The main purpose of the research is to investigate relationship between vegetation morphology and Nebkha morphometry characteristics based on statistical analyzes.

Extended Abstract:Introduction: Paleoshorelines are the most important key landforms for studying evolutionary trend of coastal sedimentary environments. Hormozgan province is one of the Iranian coastal provinces at the north of the Persian Gulf and the Oman Sea representing high variety of geological settings influenced by regional and local geological events. According to large scale coastal landmarks, sedimentary environments have been formed mainly since the late-Quaternary. Intrusion of the Precambrian salt domes, structural development of rocky coasts, and the Quaternary glacial and interglacial events have contributed in shaping of Hormozgan province’s coastal area. Fossil beaches as landmarks of regression coasts can be observed at 12 large coastal dune fields. They demonstrate superficial evidences of sea level fall tracts especially since the late-Quaternary. Recognition of the mid- Holocene mechanism of land progradation and rate of shoreline mobility is required for interpretation of regional coastal sedimentary environments. Therefore, main aim of this research was determination of evolutionary trend of paleoshorelines along the Hormozgan province.

Extended Abstract:Introduction: Liquefaction is a phenomenon in which the strength and stiffness of a soil is reduced by earthquake shaking or other rapid loading. This phenomenon is the result remolds sand particles. Soil liquefaction occurs in loose, saturated cohesionless soil units (sands and silts) and sensitive clays when a sudden loss of strength and loss of stiffness is experienced. Sometimes it is resulting of large, permanent displacements of the ground. Even thin lenses of loose saturated silts and sands may cause an overlying sloping soil mass to slide laterally along the Liquefied layer during earthquakes. Liquefaction and related phenomena have been responsible for tremendous amounts of damage in historical earthquakes around the world. Destruction of buildings, roads, land subsidence, and even loss of life is one of the dangers of liquefaction.

Extended Abstract: Introduction: Playa is considered as a dry inland with dry negative water balance which is dry in more than 3/4 of a year. Its capillary margins are so close to the surface that evaporation resulting from these margins leads to water discharge and evaporates formation. Paleophysical and paleochemical changes of a playa make significant changes in type of sediments which can be applied to determine paleosedimentary environments and their effective sedimentary processes. Sediments and minerals of salty lakes are changed by seasonal and temporal variations of sea level, so by studying sediments and minerals especially evaporate minerals in the past, sedimentary environments can be reconstructed. The present study is aimed to reconstruct and determine Holocene sub-environments in Maharlou Lake as a playa sedimentary environment which is exactly related to input– output balance of water. Maharlou is a salty ephemeral lake. It is located between 29o17’00 and 29o23’30’’ northern latitudes and 52o41’00’’ and 52o49’00’’ eastern longitude. The Lake has maximum area equals to 28 km2 situated in 18 km from southeastern of Shiraz town. The greatest length of the lake is nearly 35 km, maximum width about 15 km and average width 7 km. The Lake's height from sea level is 1455m. There is no permanent river in catchment basin of Maharlou Lake and basin's flooding is entered in the Lake by several flood plains and seasonal (monsoon) rivers.