benthic foraminiferal assemblages from maastrichtian strata, gansserina gansseri-abathamphalus mayaroensis planktonic foraminiferal zone, of the abtalkh formation at aitamir section (west of the kopeh-dagh basin) were investigated in order to evaluate the palaeoenvironmental changes (organic matter flux and bottom-water oxygenation). maastrichtian faunal assemblages are well preserved and diver...