Palaeoenvironmental assessment and lithostratigraphic revision of the Carboniferous-Early Permian succession in the Sanandaj-Sirjan Block (Iran)

Palaeoenvironment, palaeogeography, and palaeoclimatology of the Mississippian carbonate ramp in the Alborz tectonostratigraphic zone: Implications for deciphering the controlling factors on ramp evolution

“…According to the palaeogeographical map of Stampfli and Borel (2002), the various tectonic blocks of the upper Palaeozoic rocks in Iran located on the northern edge of Gondwana were covered by a shallow sea during the Mississippian global eustatic rise. In the Mississippian, the closest recent localities to the Alborz platform were areas such as Central Iran, East Iran, Sanandaj‐Sirjan Zone, the northern Arabian platform margin, and SE Turkey, all of which were continuously developing on a stable passive shelf along the southern margin of the Palaeotethys (Esfahani et al, 2019). It seems that along this stable passive shelf, the global eustatic rise has had a significant impact on the development of the flat‐topped, low‐ to moderate‐energy carbonate platform at the base of the Mobarak Formation.…”

“…The evidence of a marine regression in the Late Visean has also been reported in many parts of Central‐East Iran microplates (CEIM). In CEIM, a major sea‐level fall in the Late Visean also significantly results in the termination of platform development with thick open‐marine marls/shales of the Shishtu Formation and the formation of shallow marine and coastal siliciclastic successions during the Late Visean, Serpukhovian, and Pennsylvanian (Esfahani et al, 2019). A significant increase in siliciclastic influx as a result of this event caused the shutdown of the shallow‐water carbonate factory of the Shishtu Formation and the expansion of the sandstone progradationally stacked sequences of the Upper Carboniferous Sardar Formation.…”

“…In general, Carboniferous sequences in many Iranian basins (Alborz, Kopeh Dagh, and Central Iran basins) include shallow‐water carbonates and siliciclastics deposited on low‐angle shelves, tens of kilometres in width (Aghanabati, 2004; Bayet‐Goll et al, 2018; Esfahani, Bayet‐Goll, Kangazian, Sadri, & Mohammadi, 2019). Such a wide ramp was created subsequent to the Ordovician‐Silurian rifting phase in the northern margin of Gondwana or along the southern border of the Palaeotethys Ocean (Bagheri & Stampfli, 2008).…”