Biostratigraphy of Eocene settings in the Binalood zone (northeastern Iran) based on foraminifera

摘要

The Binalood mountain range with a northwest-southeast trend is a part of the Alborz and is considered to be a transitional zone between Central Iran and the Alborz. The Marusk section located 52 km northwest of the city of Nayshabur was selected for study of the stratigraphy of Eocene settings. The Eocene settings in this section are 1008 m thick and consist of clastic, carbonate and volcanic successions. A total of 28 species belonging to 14 genera of foraminifera have been identified and three species of larger benthic foraminifera (LBF) belonging to the nummulite genera N. herbi, N. deshayesi and N. biedai are reported for the first time from Iran. In addition, 11 species belonging to four genera of planktonic foraminifera and 13 species from nine genera of small benthic foraminifera have been recognized. Statigraphic analysis of the microfossil content suggests a time range of the Early to Late Eocene (Late Ypresian?-Priabonian?) for these settings.