Studuing environmental condition of iran pluvial lakes Using sedimentary evidences (Case study: Lut desert Kalut)

Iran’s Kaluts which are considered as special models in term of magnitude and extension, have been shaped in the west of the central Lut desert. Although these Kaluts now are influenced by the selective windy erosion, they can be shaped through the process of wind and water erosion. The suitable environment for shaping of these Kaluts are the arid region together with little raining and the intensive and continuous wind. The Lut desert Kaluts are shaped in the grounds with finer structure and wind and water erosion. This erosion can be produced when the water is accumulated in the small pit and holes in the humid season after temporary precipitation in the desert. Then a doughy substance is made and wakened. After drying and as the result of the predominate wind of the district, these pit and holes gradually become enlarged and the long silts are produce the Kaluts. In this research we want to study the sedimentary characteristics’ of Kaluts and Iran pluvial lakes by sampling of one the high Kaluts in Lut desert and experimenting sedimentary and granolometery in these samples.
Firstly, through on extensive survey in the district and visual examination of Kaluts, a high Kalut of the district was selected for modeling. Then after recording the exact position of Kalut by GPS, the related Kalut was sampled. The taken samples crushed in geomorphology laboratory and sieved by shaker. Those samples that were under 63 micron were separated in 10 grams and were used in granolometery test in Pipette way and scaled graduated cylinder. This sampling was done in two days (8 samples for the first day and 2 samples for the second). After sampling in the specific time and in the specific depth of cylinder, the samples were dried and the remained sedimentary was weighted in the beakers. Thirdly, the GradiStat software was used to analyze the number gained from the pipette test and then the related and figures were drawn.
After testing 15 layers taken from the Kalut, granolometery elements of particles such as the context and the size of particles near to the average, qualitative and quantitative measures of Sorting, Skewness and Kurtosis of particles were identified with the help of GradiStat statistical software and of statistical relationship between Folk and Ward (1975). The gathering center of bimodal and Unimodal aggregation show very poorly sorted sediment. This position could be observed in most of underneath layers. This could be produced by shaping sedimentary in the specific context that could created different particles with different sizes. According to the obtained results from statistical & experimental analysis, the context of all layers in Folk triangles was determined as muddy & their particles in the rate of silt & clay. It was expected the Skewness of all layers was positive that results show that most of layers have positive title to fine and very fine particles.
Iran kaluts are unique example of the magnitude and extent of desert areas. This Kaluts although affected by wind erosion choice currently, but water and wind erosion processes are involved in their formation simultaneously. In this study, after sampling from a Kalut with height 33 meters and 15 layers, they transferred to the laboratory and examined samples granolometery tests.The finding reveal that the Kalut sedimentary in the rate of silt & clay have horizontal and lamination classification referring this fact that the tiny sedimentary hanging in the water and were deposited in a calm environment. Furthermore, on the muddy silts were observed some chaps. The silts were produced when the lakes were dried and the water was vaporized severely and then the sediments could be observed in the form of salty and chalky layers of Kaluts along with silt and clay particles that carried by the wind. This fact can be certified with the respect to this fact in the past the shallow lake in the low energy environment was severely vaporized and dried. As a result of this, the chalky and salty layers were made. Based on the experiments, the most of the related layers have the muddy context with very bad sorting and fine skewness that this reveals that the following activities in the district was low and the environment was low energy during sediment of the kaluts.