The palynostratigraphy of the Lower Carboniferous (middle Tournaisian–upper Viséan) Shishtu Formation from the Howz-e-Dorah section, southeast Tabas, central Iranian Basin

Abstract

Palynological analysis of the Shishtu 2 Member (Shishtu Formation) located in the Howz-e-Dorah area (southeast Tabas, central Iran Basin) suggests a middle Tournaisian–late Viséan age for this rock unit. The Shishtu 2 Member consists of shale, sandstone, dolostone and limestone. Three palynological assemblages are recognised and mainly correlated with the miospore biozones of Northern Gondwana. A microfloristic comparison with other sections in Western Gondwana (South America) is also proposed. We identify a sedimentary hiatus between the Shishtu 1 and Shishtu 2 members. Our findings suggest that the Mush Horizon is the lowermost part of the Shishtu 2 Member, contrary to the Iranian literature where it is considered to be the uppermost part of the Shishtu 1 Member.

Keywords:

• Carboniferous
• Mississippian
• spores
• Tabas
• central Iran Basin
• Shishtu Formation

Acknowledgements

The authors would like to thank the management of NIOC for permission to publish this paper, and we are indebted to Mr. Hossein Sabbaghiyan (NIOC), Dr. Marco Cherin and Dr. Enrico Capezzuoli (University of Perugia) for their valuable suggestions. Special thanks are due to Prof. Bahaedin Hamdi (Department of Geology, Faculty of Science, Azad University of Tehran, Iran) for the conodont data. Mr. Adrian Wallmark is thanked for the English review. We would thank also the ARIANZAMIN Pars Geological Center for the management, field trip and sampling. Grateful acknowledgment is extended to two anonymous reviewers for their helpful comments on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Mohammadreza Aria-Nasab

MOHAMMADREZA ARIA-NASAB graduated in paleontology from Tehran University in 1995. He is a PhD student at Kharazmi University, Tehran, Iran. Mohammadreza's PhD thesis focuses on the Carboniferous sediments in Central Iran and since 1998, he has been employed by the National Iranian Oil Company (NIOC). His main experience is on Paleozoic palynomorphs and foraminifers.

Amalia Spina

SIMONETTA CIRILLI is full professor in Sedimentary Geology at the Department of Physics and Geology of the University of Perugia, Italy. Her research interests focus on sedimentology and stratigraphy of marine carbonate, mixed carbonate-siliciclastic and continental depositional environments; palynology and organic matter studies and their application in sequence stratigraphy; relationships between facies distribution and source rocks and reservoirs.

Simonetta Cirilli

JAHANBAKHSH DANESHIAN received his PhD from the University of Delhi, India in 1999. He is now an Associate Professor at the Department of geology, Kharazmi University, Tehran, Iran and focuses his research on micropaleontoly and biostratigraphy.

Jahanbakhsh Daneshian

AMALIA SPINA graduated in geology from the University of Perugia, Italy in 1997, and received her PhD from the University of Siena, Italy in 2004 for a thesis on Late Palaeozoic to Triassic sporomorphs from Tuscany and the Southern Italian Alps. She has undertaken postdoctoral positions at the University of Siena, the Italian National Research Council, the University of Lille 1, France and the University of Perugia. Amalia is now a research assistant at the University of Perugia, where her research is mainly on the Palaeozoic stratigraphical palynology of Gondwana.