Biostratigraphy of eocene sediments from Naopurdan Group, Chwarta Area, Kurdistan Region, NE Iraq: paleogeographic implication

Abstract EN

The main purpose of the present work is to describe the microfossils and biostratigraphy of marine Eocene deposits, which are described and studied in detail from carbonates of the Naopurdan Group, Chwarta area, Kurdistan Region, Northeastern Iraq.

In order to define the main index fossils and to establish the biostratigraphy and age constraints of the exposed unit in the study area.

A total of thirty-eight samples, spaced ca 0.5 to 1 m apart, have been collected from the field, approximately 60 thin sections are examined and the microfossils have been identified using the polarized microscopes.

Three main biozones are recorded in the studied section, these zones are : (Nummulites globulus - Nummulites planulatus zone, at the bottom of the section and assigned to the Early Eocene (Ypressian) age, Nummulites mamillatus - Nummulites alsharhani zone, collected from the middle part of the section is assigned to the Middle Eocene (Lutetian) age, and Nummulites fabianii - Assilina exponens zone collected from the upper part of the section is assigned to the Early Bartonian age.

So, the studied section of the Naopurdan Group is suggested to be Ypressian- Early Bartonian age.

These three biozones are correlated with the other zones inside and outside Iraq.