Facies and architectural elements of Zayandeh-Rud river bank (Ghortan - Varzaneh)

Alluvial deposits of Zayandeh Rud river bank, between Ghortan and Varzaneh area, consist of 3-4 m fining upward of gravelly, sandy and muddy sediments.They include 10 lithofacies of matrix supported gravel)Gmm), clast supported gravel(Gcm, Gci), horizontally stratification gravel(Gh), planar cross bedded gravel(Gp), trough cross bedded gravel (Gt), trough cross bedded sand (St), planar cross bedded sand (Sp), massive mud(Fm), intermittent sand and mud(Fl).All lithofacies have formed in 8 architectural elements of channel (CH), gravity flow deposits (SG), levee (LV), crevasse splay (abandoned channel) (CS, FF (CH)), sandy bed forms (SB), laminated sand sheet (LS) and lateral accretion (LA).The facies and architecture elements are mostly developed in a meandering river system in arid to semi arid climate. Deposition of debris flow sediments in lower part of succession suggest both sedimentation activity of alluvial and fluvial systems in the study area.