Impact of Geographic Location and Tectonic specification of Sistan Plain in transferring of fine grained Sedimentary in eastern Iran

Vigorous energetic and long lasting winds specially in hot-arid regions that lack a green cover and are usually covered with granular deposits of minerals such as quartz, various salts and soils, results in movement of sedimentary fine grains and vast scatter of them in atmosphere. Reduction of moving energy of wind causes the scatter of the fine grains to stop. These grains are scattered through the atmosphere in great distances and finally sediment on the ground, under water and in natural, herbal, animal and human environments. Geographically and climatically speaking, Iran, its western neighbors (including Iraq, Kuwait and Saudi Arabia) and its eastern neighbors (including Afghanistan and Pakistan) are all located on the northern arid belt of the globe. Geographical images and geological structures of Iran shows that a large portion of the country, specially in the center and east, including interior low desert lands (like Dasht-e-lout in between the provinces of Kerman, Sistan Baluchestan and Southern Khorasan, which experience a temperature of 70.7 oc in 2005 and was recorded as the hottest point on the earth and Kavir-e-Lout in south of Alborz mountains which experiences a temperature variance of 70 oc ) is surrounded by numerous mountains inside and outside of the country (like Hendokesh mountain 8300 meter high). Consequently, geographical position and geological structure of Iran causes various parts of great country of Iran and its neighbors, specially in south-west parts near Iraq, central and eastern parts of Iran near Afghanistan, are favorable areas for production of strong winds and movement of sedimentary fine grains near the ground surface and scatter of grains in atmosphere in geographical region of Iran an neighboring countries. Geographical area of Sistan plane in east of Iran (with and average precipitation of 61 mm and average evaporation of 4000- 5000 mm) with and average of 80/7 days of dust storm in the year in a five year period (1990-1995), stands the second place of dust storms in Asia. During the statistical period of 1976-2005, vigorous winds and dust storms with scatter of sedimentary fine grains are reported in more than half of the year, especially during the summer. In south east of Iran and specially in the lowland of Sistan, numerous winds blow including: the Qows wind, seventh wind known as Cow-killer wind, Palpalasi wind or swallow wind, Qible wind, Bad Lavar and well-known 120-days winds. 120- days wind is one of the important winds and blows in a great area, east of Iran. This wind starts from high-pressure areas of Afghanistan’s Hendokesh Mountains and enters Iran through Khorasan borders. It elevates in hot low lands of Kavir-e-lout and moves toward low lands of Sistan. This wind lasts for more than 120 days (the number of windy days in the Sistan region has reached 170 days in recent years), with an average speed of about 100 km / h (120-day wind speed in the Sistan region in recent years). 150 to 170 km.) With the general direction of northnorthwest during the spring and summer seasons throughout the central and eastern region of Iran and western Afghanistan, along with other powerful winds in the region, by uplifting and transporting fine grains from The surface of the earth, creates hole with a 2-3 meters radius ad 6-9 meters deep. In addition to the global geographic location - the location in a warm and dry climate belt, - and the general geological structure of Iran in the South Asia region (the placement of low ground in the vicinity of high mountains The vast tectonic descent of the Sistan Plain (with an average elevation of 475 to 500 meters above sea level), the proximity of the Hindu Kush Highlands in Afghanistan (from the east), and the Lout desert lands in Iran (from the west) Causes the formation of long and intense winds such as 120-day high and long winds of Sistan, especially during the warm seasons during the spring and summer seasons in the Sistan and adjoining areas,Development of warm and dry weather conditions, especially in the last 20 years, and stopping the flow of water in the Hirmand River (about 1050 km long), water for the survival of the vast lake of Hamoon (with a total area of 5660 km2 and a watershed of 34273 km) and average depth of about 4 m in high water days), Drying of Hamoon Triple Lakes (Hamoun Sabori, Hamoon Poozak, Hamoon Hirmand) with Rossi-Salt Bed and... The main determinants of the displacement, uplift and dispersal of fine sedimentary minerals in the atmosphere of the eastern parts of Iran, especially in Sistan, Southwest Afghanistan, Northwest Pakistan and the Oman Sea, adjacent to the Indian Ocean. This article, explores the geographic location and geological structure of the Sistan plain in creating high-energy wind tunnels and the displacement and distribution of finegrained grains in the atmosphere of the region by introducing geographic location and geological structure of Sistan Plain.