Physiography and Geomorphology of Tabarak Dam watershed, north of Quchan, and their effects to type of deposits

Tabarak Dam watershed is one of the main water supply of Atrak river, where located at north of Quchan. Geologically, Tabarak Dam watershed is a part of Kopet-Dagh basin.Watershed boundary is marked by Allah-Akbar Mountains and Zoo-Baran anticline. This watershed is divided to Zir-Abeh and Yadak sub-basins. Generally, due to present of different type of rock units, and tectonic effects, two areas, flat plain at Zir-Abeh sub-basin and mountain area at Yadak sub-basin have been formed. According to physiographic features, Tabarak Dam watershed is classified as a mean and elongate basin. The mean high of Tabarak Dam watershed is 1884.96 m, and the average gradient is about 23%. In addition, about 50 of basin shows 20-40 degrees slope. So, this basin is one of the high slope basins in this area. At Tabarak basin, some geomorphologic phenomenons, such as gully, rilly erosin, tallus, alluvial fan and landslide have been identified. Additionlly, different lithology has mostly caused to form drainage patterns such as denderitic and trellis. The identified sedimentary facies are gravelly (Gmm, Gcm), sandy (Sm) and muddy (Fl, Fm, Fr) facies, which are result of effect of physiography, geomorphology and lithology factors of study area.