Study of sand dunes origin by geochemical trades of eolian sediment in Niatak

Recognition of origin of sand dunes is very important in wind erosion control projects. Due to the difficulties in application of traditional methods in recognizing and determining the share of sediment sources in sediment yield, fingerprint method, sediment tracery, or in other wards, source identification are alternative and suitable methods which are considered by some researches. In this method, by analysis of physical and chemical characteristics of sediments, rocks and soils in different places, source areas of sediment yield are determined. In this study, sediment tracery by geochemical elements, source areas and the shares of these sources in eolian sediment yield in one of the most important eolian centers of Sistan plain were identified. First, granulometry and mineralogical studies were performed on eolian sediments of Sistan province. Then, step-wise source identification method was performed on Niatak eolian sediments. Using determination analysis and composite multivariate methods and also selecting suitable composition of geochemical elements, organic carbon, phosphorous and nitrogen which can differentiate lithological, land use and geomorphological units in Niatak, importance and share of sediment sources were determined. Results indicate that the transport distances are between 20 to 50 Km and the most important sources were sediments of Hamon lake (92%) and bare land (87%). 87% of the particles originates from NQts unit (upper Miocene – Pliocene fine – grained alluvial sediments of Hamon lake), which has the highest share and QK unit (the youngest lucastrine sediments of Hamon) has the lowest share.