Comparative evaluation of age and weathering condition of alluvial deposits which associate to some environmental settings during their formation is a matter of interest in various fields of studies. The aim of this study was to compare age and weathering of two strath terraces of the Sirvan river in western Iran at its three cut-banks (1, 2 and 3) accessible for sampling. AMS 14C dating revealed 15090±50 and 18510±60 yrs BP for terrace T1 at the cut-banks 1 and 2 , respectively, and 10870±40, 11300±40 and 14610±40 yrs BP for terrace T2 at the cut-banks 1, 2, and 3, respectively. Evaluation of weathering using some coordination systems, where crystallinity ratio of iron oxides was considered as x-axis and indexes of either Parker or Product were set as y-axis showed more intensive weathering among older deposits for each of terraces T1 and T2. However, weathering condition of the two terraces were incomparable mostly due to deeper deposits and finer particle size distribution of terrace T1 than terrace T2 and also colder climatic condition of terrace T1 before formation of terrace T2. It seems all of these differences have discouraged weathering processes in terrace T1 through reducing of weathering factors influences. Color parameters of a* and b* in CIE color standard explained the intensity of reddish and yellowish of crystalline iron oxides of the river deposits, which functioned to discuss the order of emergence of the river terraces in the studied area.
