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

摘要

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 Visean; 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 Visean or early Serpukhovian age for the sampled Shishtu 2 section is suggested here.