Sedimentology and paleo current direction of the Fan deposits (Quaternary) in Hashtgerd area

In the recent decades, with increasing in human need to produce more food and their encountering with high risk geological phenomena like earthquake and bioenvironmental pollutions, the importance of the quaternary system and realizing its different aspects for geologists were increased. This research considers the scientific phenomena occurred in Hashtgerd area. It is located between 35°52′30″N and 36°00′00″N latitudes and 50°37′30″E and 50°45′00″E longitudes. Topographic elevations in the province vary between 1310 and 1610 m. This area has placed in the southern slopes of the Alborz Mountains and in the northern edge of the central desert of Iran and 40 km west of Karaj. Morphologically this area located on an alluvial fan which is 16 km2. In the northern part, sediments seem older and brighter and have higher cementation and often are related to Paleo-quaternary sediments. The young quaternary sediments have been placed on this alluvial Fan and the sediments are getting more loos and more red toward south. The age of deposits in this area is Pliocene up to present. The Pliocene deposits are the oldest and the agricultural soil and the alluvial deposits are the youngest. The most available dominant lithology is also Tuff.