Fusulinoids from the Carboniferous–Permian transition beds from the Abadeh Region (Sanandaj–Sirjan Zone, Iran)

Discovery of Late Mississippian (late Serpukhovian)–Early Pennsylvanian (earliest Bashkirian?) foraminiferal assemblages from the Sanandaj–Sirjan Zone, Iran: Biostratigraphic and palaeoenvironmental implications

“…As Leven and Gorgij (2011b) declared, the Sardar Group unconformably overlies the Shishtu Group and consists of the Ghaleh and Absheni formations, which correspond roughly to the Bashkirian and Moscovian stages. However, the conodont data (Boncheva et al, 2007) and the foraminiferal evidence (Fassihi et al, 2017, 2018; this study) show that the stratigraphic range of the Ghaleh Formation is from the upper Serpukhovian–lowermost Moscovian, rather than the Bashkirian. The Ghaleh Formation is composed chiefly of limestone, with argillite, aleurolite, and sandstone intercalations.…”

“…These strata, together with about 11 m of the crionoid horizon and 13 m conglomerate, cap the strata of the lower Viséan beds with a stratigraphic unconformity corresponding to the middle Viséan–early Serpukhovian (see Figure 2). The Visean deposits of the Asad Abad II section were originally assigned to two local biozones: (1) Uralodiscus rotundus–Glomodiscus miloni Zone corresponding to the MFZ11B and (2) Lapparentidiscus bokanensis Zone corresponding to the MFZ12 foraminiferal biozone of the stratotype area of the Viséan Stage of the Dinant Basin in Belgium (Fassihi et al, 2018; Fassihi & Shirezadeh, 2018). However, as declared by Cózar et al (2020) in a revision of the lower–middle Viséan boundary interval of the key sections of the Paleotethys, the L .…”

“…varvariensis (Brazhnikova & Potievskaja, 1948) (samples R71–R74). The strata bearing these faunas were initially assigned to the lowermost part of the Bashkirian (Voznesenkian), corresponding to the Plectostaffella jakhensis‐Eostaffella pseudostruvei Zone (e.g., Fassihi, 2017; Fassihi & Shirezadeh, 2018). Many species found in this assemblage continue from the underlying beds.…”

“…The presence of Serpukhovian foraminifers in the Sanandaj–Sirjan Zone was first described in preliminary reports by Fassihi et al (2017) and Fassihi and Shirezadeh (2018). The current study exhaustively delineates the Serpukhovian foraminiferal faunas in this tectonic block.…”

“…Carboniferous marine deposits are widely distributed in the Sanandaj–Sirjan Zone, where the studied biostratigraphic section is located. However, except for a few studies (e.g., Baghbani, 1993; Fassihi, 2017; Fassihi et al, 2017, 2018, 2019; Fassihi & Shirezadeh, 2018; Leven & Gorgij, 2008b), the foraminiferal faunas have not been investigated in detail. The age of the Carboniferous interval in this area is mainly determined based on conodonts (Bahrami et al, 2014; Boncheva et al, 2007).…”