Sedimentology of the of Zayandeh-Rood River alluvial Terraces and the sediment source identification

In this research, three alluvial Terraces that are located in pathway of Zayandeh-Rood River are studied. The river starts from Bakhtiayri Zardkoh mountain and after through Esfahan city ends to Gawkhony lake. Age of alluvial terraces is younger in upstream than downstream and the height level of the terraces decrease relative to current river bed toward the downstream. The terraces were sampled, and then granulometery test and the source identification were performed on the sediments. The results showed that the majority of samples shave poor sorting and different skewness. The conditions probably display the variation in river regime with climate changes during Quaternary period. The source identification has showed that much of sediments are schist fragments from the northern Shahrekord metamorphic complex and limestone. The sediments have originated from different locations in pathway of the river. Some of the limestone fragments have microfossil with Eocene age probably correlated with the Jahrom formation in Zagros Zone. The limestone sediments are been transported to the study area from the formations which are situated before Zayande-Rood dam.