Paleocene-Eocene Calcareous Nannofossil Biostratigraphy and Cyclostratigraphy From the Neo-Tethys, Pabdeh Formation of the Zagros Basin (Iran)

Azami, Seyed Hamidreza; Wolfgring, Erik; Wagreich, Michael; Mahmudy Gharaie, Mohamad Hosein

Abstract

The Pabdeh Formation in the Zagros Basin, Iran, records cyclic pelagic sedimentation from the middle Paleocene to the middle Eocene in a Tethyan setting. The cyclic successions consist of deeper-water pelagic to hemipelagic shale, marl (stone) and limestone, with a predominantly shaly lower part, and a marl-limestone upper part. Nannofossil biostratigraphy indicates standard zones CNP8 - NP6 to CNE8 - NP14. The Paleocene-Eocene Thermal Maximum (PETM) interval is indicated by a distinct nannofossil assemblages and a significant negative carbon isotope excursion. Sediment accumulation rates are in general around 6–68 mm/ka. Cyclic signals investigated include fluctuations in carbonate content. Power spectra using LOWSPEC (Robust Locally-Weighted Regression Spectral Background Estimation) and EHA (Evolutive Harmonic Analysis) indicate the presence of twentyone 405 ka cycles from the base of the PETM up to the top of the studied section. Orbital tuning to the established Laskar target curve is in accordance with the general Paleocene-Eocene cyclostratigraphy and yields insights into Paleogene chronostratigraphy.

Citation

Azami, S. H., Wolfgring, E., Wagreich, M., & Mahmudy Gharaie, M. H. (2018). Paleocene-Eocene Calcareous Nannofossil Biostratigraphy and Cyclostratigraphy From the Neo-Tethys, Pabdeh Formation of the Zagros Basin (Iran). In M. Montenari (Ed.), Stratigraphy & Timescales (357-383). Elsevier. https://doi.org/10.1016/bs.sats.2018.08.006

• Online Publication Date: Sep 11, 2018
• Publication Date: 2018
• Deposit Date: Jun 5, 2023
• Publisher: Elsevier
• Pages: 357-383
• Series Title: Cyclostratigraphy and Astrochronology
• Series ISSN: 2468-5178
• Book Title: Stratigraphy & Timescales
• Chapter Number: 9
• ISBN: 978-0-12-815098-6
• DOI: https://doi.org/10.1016/bs.sats.2018.08.006