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

ABSTRACT

This assessment of the article by Aria-Nasab et al. (2016), on the palynostratigraphy of the upper part of the Shishtu Formation (Shishtu 2) in central Iran, reveals many shortcomings. The majority of the defects are judged to reflect unwarranted or erroneous taxonomic identifications of the adversely preserved miospores. This, in turn, casts considerable doubt on the compositional integrity of Aria-Nasab et al.'s three proposed stratigraphically successive miospore assemblages, which they dated as encompassing the mid Tournaisian through late Viséan; i.e. within the generalised Mississippian age for Shishtu 2 that had previously been established from marine faunal evidence. We confirm, through examination of their illustrations, the presence of recycled Late Devonian palynomorphs, including Retispora lepidophyta. A late Tournaisian through late Viséan or early Serpukhovian age for the sampled Shishtu 2 section is suggested here.

KEYWORDS:

• palynostratigraphy
• Mississippian
• Shishtu Formation
• Central Iran Basin

Acknowledgements

We thank Dr James Riding (Managing Editor, Palynology) for encouragement and advice; and Dr Amalia Spina (Università degli Studi di Perugia) for graciously facilitating our access to some slides of the Shishtu 2 Member, as studied by Aria-Nasab et al. (2016). Special thanks are extended to Dr Duncan McLean (MB Stratigraphy Ltd, Sheffield): the manuscript has benefited appreciably from his meticulous and insightful review.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Geoffrey Playford

GEOFFREY PLAYFORD – a graduate of the Universities of Western Australia (BSc Hons I, DSc) and Cambridge (PhD) – is a professor emeritus in the School of Earth and Environmental Sciences, The University of Queensland (UQ). While a senior undergraduate at the University of Western Australia, he was introduced to palynology by the inspirational Dr Basil Balme, then newly appointed to the university. Geoff's initial appointment to a lectureship in geology at UQ was preceded by doctoral research at Cambridge (supervised by Dr Norman Hughes) followed by tenure of an NRC postdoctoral research fellowship at the Geological Survey of Canada, Ottawa. During periods of sabbatical leave from UQ, he has conducted collaborative research, notably with Dr Francine Martin (Belgium), Dr Colin McGregor (Canada), Prof. Reed Wicander and Merrell Miller (USA), Prof. Marco Tongiorgi (Italy) and, more recently, with Drs Rodolfo Dino and José Henrique Gonçalves de Melo (Brazil). He has published extensively on a diverse range of Palaeozoic and Mesozoic palynomorphs, with main emphasis on their stratigraphic applications.

Hossein Hashemi

HOSSEIN HASHEMI has been an associate professor in the Department of Geology, Faculty of Earth Sciences, Kharazmi University, Tehran, Iran since 1999. He obtained his MSc degree from Tehran University in 1990, working on Early Permian palynomorphs from the Alborz Ranges, northern Iran. Awarded a PhD scholarship by the Australian government, he continued research on Palaeozoic palynomorphs under the supervision of Prof. Geoffrey Playford and received his doctoral degree from The University of Queensland in 1997. He is principally interested in the systematics and stratigraphic applications of Palaeozoic and Mesozoic palynomorphs.

Reed Wicander

REED WICANDER is a professor emeritus of geology at Central Michigan University, USA, where he taught for 39 years. He is currently an adjunct professor in the School of Earth and Environmental Sciences, The University of Queensland, Brisbane, Australia. Reed earned his BS degree in geology from San Diego State University in 1969 and his PhD degree from the University of California, Los Angeles in 1972 under the guidance of Dr Helen Tappan Loeblich and Dr Alfred R. Loeblich, Jr. His palynological research focuses on Palaeozoic acritarchs and prasinophytes, and he has published more than 50 peer-reviewed research papers during his career. He has also published numerous editions of both physical and historical geology textbooks with his long-time faculty colleague, Dr Stewart Monroe.