Evolutionary trend of Cenomanian alveolinids from Zagros Basin,SWof Iran

Abstract

The alveolinids were once highly widespread in the Cenomanian of the Tethys Basin. Even though evolutionary studies have, thus far, been conducted using material from many countries e.g. Spain, Oman, and the UAE, the Zagros region in SW Iran has not been studied yet. Two sections of the Sarvak Formation in the Pyun and Kuh‐e‐Zana areas were investigated. Five type levels can be identified in the Pyun section. The evolutionary trend begins with praealveolinids followed by ovalveolinids in the Early Cenomanian. Cisalveolinids firstly appear in the Late Cenomanian strata and then Multispirina is derived. Then Simplalveolina simplex appears, which is derived from Multispirina iranensis. At the Kuh‐e Zana section, the evolutionary trend was observed in three levels. There is no ideal evolutionary trend because Multispirina and Simplalveolina are absent in this section. The identified trends are similar to those of the Iberian Ranges in Spain.

Notes to Comment on “Evolutionary trend of Cenomanian alveolinids from Zagros Basin, SW of Iran” by Consorti and Vicedo (2022) in Geological Journal

“…However, the number of whorls and the structure of chambers, chamberlets, septula and preseptal passage are recognized for observed alveolinids in the Sarvak Formation. Moreover, the structural elements of investigated alveolinids compared with several previous works that consisted of the various sections (sagittal, axial and tangential type; e.g., Calonge et al, 2002; Caus et al, 2009; Dousti Mohajer, Afghah, Dehghanian, & Sheikh Zakariaii, 2021, Dousti Mohajer, Afghah, Dehghanian, & Abyat, 2021; Ghanem & Kuss, 2013; Ghanem et al, 2012). The structural form of chamber and chamberlets coincided with the previous works that were recorded as common alveolinids in the Middle East (e.g., Afghah & Fadaei, 2015; Afghah, Yousefzadeh, & Shirdel, 2014; Dousti Mohajer, Afghah, Dehghanian, & Abyat, 2021; Dousti Mohajer, Afghah, Dehghanian, & Sheikh Zakariaii, 2021; Dousti Mohajer et al, 2022; Ghanem et al, 2012; Ghanem & Kuss, 2013).…”

“…Also, in other identification of foraminifers, the embryonic zones are so significant for the determination of the species, but several previous works are represented without embryonic zones of the distinct species that are mentionable to Orbitolinidae with semi‐preserved samples (e.g., Baud, Cherchi, & Schroeder, 1994). Therefore, the adductions on alveolinid identification (Dousti Mohajer, Afghah, Dehghanian, & Sheikh Zakariaii, 2021; Dousti Mohajer, Afghah, Dehghanian, & Abyat, 2021) are completely unacceptable. Moreover, the essence of biostratigraphy is established by corrected identification.…”

“…Moreover, the other taxonomic characteristics (e.g., size and form of the tests, number of whorls, and form, strongly coincide with the latest study on Cretaceous alveolinids, particularly in the Middle East and Tibet (Boudagher‐Fadel & Price, 2021). The phylogenic and taxonomic characterization of the Ovalveolina test as a globular form was recognized in the Zagros Basin (Afghah et al, 2014; Afghah & Fadaei, 2015; Dousti Mohajer, Afghah, Dehghanian, & Abyat, 2021; Dousti Mohajer, Afghah, Dehghanian, & Sheikh Zakariaii, 2021). Other skeletal characteristics, such as the pre‐septal canals and post‐septal passage of Cisalveolina were recognized in the received data which was recorded previously in the Sarvak Formation (Afghah et al, 2014; Khosrow‐Tehrani & Fonooni, 1994).…”

“…Both Cenomanian shallow water and pelagic sediments of the Sarvak Formation in the Zagros Basin are well‐known oil reservoir rocks. The Formation has been studied from the point of view of biostratigraphy, facies analysis, and sequence stratigraphy (Arampour, Afghah, & Parvaneh‐Shirazi, 2021; Assadi, Honarmand, Moallemi, & Abdollahei‐Fard, 2016; Dousti Mohajer, Afghah, Dehghanian, & Abyat, 2021; Dousti Mohajer, Afghah, Dehghanian, & Sheikh Zakariaii, 2021; Dousti Mohajer, Afghah, Dehghanian, & Sheikh Zakariaii, 2022). Arising from the previous studies, the Sarvak Formation of the Interior Fars Zone is significant as a shallow‐water sequence that consists of benthic foraminifers in the Fars carbonate platform (Afghah & Dookh, 2014; Afghah & Fadaei, 2015).…”

“…Arising from the previous studies, the Sarvak Formation of the Interior Fars Zone is significant as a shallow‐water sequence that consists of benthic foraminifers in the Fars carbonate platform (Afghah & Dookh, 2014; Afghah & Fadaei, 2015). Despite the fact that alveolinids have been not previously recorded in many biostratigraphic collected data, Dousti Mohajer, Afghah, Dehghanian, and Abyat (2021) and Dousti Mohajer, Afghah, Dehghanian, and Sheikh Zakariaii (2021) successfully reported the alveolinids in the Fars carbonate platform. The selected stratigraphic section is attributed to the Izeh zone (sub‐division of Fars carbonate platform, Coastal Fars Zone) which is named herein as the Pyun section.…”