Biostratigraphy and carbon-isotope stratigraphy of the uppermost Aptian to Upper Cenomanian strata of the South Palmyrides, Syria

Abstract

Biostratigraphic and carbon-isotope data were used to introduce a high-resolution stratigraphic reference section of the Upper Aptian to Upper Cenomanian platform carbonates of the South Palmyrides in Syria. We studied the biostratigraphic evolution of the Zbeideh to Abou-Zounnar formations in two sections, based on 42 species of benthonic foraminifera and 38 species of planktonic foraminifera. Comparisons with other Tethyan assemblages allowed determining 11 biozones; six are based on planktonic foraminifera, and five on benthonic foraminifera. Four hiatuses (earliest Albian, Middle–Late Albian, Late Albian–Early Cenomanian, and Mid Cenomanian) are marked by hardgrounds or dolomitic intervals. The planktonic biozones Ticinella bejaouaensis, T. primula, T. praeticinensis, Rotalipora subticinensis, R. globotruncanoides and R. cushmani co-occur with the following benthonic biozones: Mesorbitolina texana partial range zone, M. subconcava range zone, Neoiraqia convexa taxon-range zone, Praealveolina iberica interval zone and Pseudedomia drorimensis range zone. Within this biostratigraphic framework, a new carbon-isotope curve from the South Palmyrides was compared with δ13C records of the Tethyan Realm and England that allows identifying several biotic events and Oceanic Anoxic Events (OAE), recorded in the Upper Albian to Upper Cenomanian succession. The combination of sequence-stratigraphic interpretations and comparisons, with our results have led to an improved understanding of the Cretaceous platform architecture of the South Palmyrides that links the Arabian Platform to the east with the Levant Platform to the southwest.

Biostratigraphy, Microfacies and Depositional Environment of the Sarvak Formation at the Pyun Anticline (Zagros Basin, Southwest of Iran)

“…Laboratory studies were conducted, including the preparation of microscopic sections as well as the analysis and diagnosis of the microfossils in the prepared thin sections. The foraminifers and calcareous algae were identified according to Reichel (1936), Khosrow Tehrani andFonooni (1994), Velić andVlahović (1994), Husinec et al (2000), Calonge et al (2002), Velić (2007), Ghanem et al (2012), Ghanem and Kuss (2013), Afghah et al (2014), Afghah and Fadaei (2015), Consorti et al (2015), El Baz and Khalil (2018), Omaña et al (2019), the determination of microfacies and paleoenvironment being carried out following Wilson (1975), Carozzi (1989), Lasemi and Carozzi (1981), Burchette and Britton (1985), Geel (2000), Flügel (2004Flügel ( , 2010 and Razin et al (2010).…”

“…25 (Wynd, 1965), orbitolinid (Trocholina) zone 1 (Wood and Lacassange, 1965), Nezzazata-alveolinids assemblage zone (Khalili, 1976;Bolz, 1977) and Nezzazata-alveolinids zone and oligosteginid facies (Bourgeois, 1969). Beyond the Iranian border, this zone is analogous to the O. maccagnoae-S. viallii taxon range zone and O. maccagnoae-C. gradata interval zone of Velić and Vlahović (1994) from the Early Cenomanian of Croatia, the C. conica-C. cuvillieri range zone of Ghanem and Kuss (2013) and Ghanem et al (2012) from Syria, the D. cenomana-Mayncina interval zone of El Baz and Khalil (2018) from Egypt, as well as the base of the P. dubia-B. bentori cenozone of Tasli et al (2006) from Turkey.…”

“…The P. iberica-C. gradata interval zone is defined as the interval from the first occurrence of P. iberica to the first occurrence of C. gradata. P. iberica was recorded in France (Reichel, 1936;Dufaure, 1959;Cherchi and Schroeder, 1989), Spain (Reichel, 1936;Viallard, 1966;Feuillé e, 1967), Lebanon (Saint-Marc andDubertret, 1974), Portugal (Berthou, 1973;Berthou and Schroeder, 1978), Italy (Mancinelli et al, 2003), Karst Dinarides (Velić, 2007), Syria (Ghanem et al, 2012;Ghanem and Kuss, 2013) and Iran (Afghah and Fadaei, 2015), all as Early Cenomanian. Other important species found in the material examined are P. debilis, O. crassa and O. maccagnoae, which represent an Early Cenomanian age.…”

“…Velić and Vlahović (1994), Velić (2007) and Ghanem et al (2012) investigated O. crassa and O. maccagnoae in Early Cenomanian strata. Gušić et al (1988), Fuček et al (1990), Gušić and Jelaska (1990), Velić and Vlahović (1994), Husinec et al (2000), Velić (2007), Korbar et al (2001), Ghanem et al (2012), Piuz et al (2014) and Afghah and Fadaei (2015) documented the first occurrence of C. gradata in Middle Cenomanian. Therefore, the age of this biozone is Early Cenomanian.…”

“…The mentioned taxon was recorded in the Karst Dinarides (Velić, 2007), Croatia (Velić and Vlahović, 1994), Syria (Ghanem et al, 2012) and Oman (Piuz et al, 2014) in Early-Middle Cenomanian contacts. Gušić et al (1988), Fuček et al (1990), Gušić and Jelaska (1990), Husinec et al (2000) and Korbar et al (2001) (2015) from Iran stated that C. fraasi (fallax) is limited to upper Cenomanian rocks.…”