Systematic Paleontology of Bartonian Larger Benthic Foraminifera from Shahrekord Region in High Zagros, Iran

Abstract

The Jahrum Formation is characterized by abundant benthic Foraminifera in carbonate beds, partly marly and dolomitic limestones in the Kuh-e-Soukhteh (Shahrekord region). This formation covers a huge stretch of the Zagros Zone which is a part of the central Tethyian realm during the Paleogene time. Bio-stratigraphic analysis of the larger benthic Foraminifera distinguishes one assemblage zone assigned to the late middle Eocene (Bartonian). This new biostratigraphic range is represented by the index fossil Rhabdorites malatyaensis (Sirel) and is correlated with calcareous rocks in the Shiraz area (south Iran), Dhofar section (Oman), and Socotra Island (Yemen). The Jahrum Formation is dominated by rich miliolids-agglutinated Foraminifera with rare small rotaliids and without Nummulites Lamarck and Alveolina d'Orbigny indicating that the formation was deposited in a shallow water environment (nearshore lagoonal zone) with low energy.