Biostratigraphy of the Late Cretaceous/Early Paleocene Successions at K.H 5\6 and K.H 5\8 Core Interval, Western Desert of Iraq

Abstract

The core interval at the K. H5\6 and K.H5\8 wells in the west of Rutba province reveals a significant succession across the Late Cretaceous-Early Paleocene transition. The sampled interval encompasses a series of carbonates belong to Digma Formation of Latest Cretaceous age, which underlies the Akashat Formation of Danian age. Fifty-five species belong to thirty-five genera were recognized. Based on the distribution of these species, eight biozones were distinguished, three biozones are recorded from the K.H 5\6 studied section and two biozones are documented from the K.H 5\8 studied section which refers to Late Maastrichtian age of Digma Formation. Five biozones are recorded from Akashat Formation in the K.H 5\6 studied section and only one biozone is documented from the K.H 5\8 studied section which refers to Danian age. The depositional environment of the studied successions proposed it accumulated in the outer ramp environments.

Foraminiferal Biostratigraphy of the Uppermost Cretaceous Period, Duhok Area, Kurdistan Region, North of Iraq

“…This zone is also comparable to the Pseudoguembelina palpebra CF2 Zone of Hammoudi (2011) from Shaqlawa area, Al-Mutwali and Al-Doori (2012), Salih et al (2013), Al-Mutwali andIbrahim (2019) from north of Iraq. The CF2 Zone of the current study is match to the same zone recorded by Mousa et al (2020) from the Western Desert of Iraq and Al Nuaimy et al (2020) from Sulaimani area NE Iraq (Fig. 5).…”

“…Salih et al (2013) and Al-Mutwali and Ibrahim (2019) recorded the same zone from Northern and Northeastern Iraq. The Plummerita hantkeninoides Zone is correlated to the same zones of Mousa et al (2020) from the Western Desert of Iraq and Al Nuaimy et al (2020) from Sulaimani North East of Iraq (Fig. 5).…”

“…Many studies of the uppermost Cretaceous deposits in Iraq and Kurdistan Region suggested that the Cretaceous ends with probably abrupt, erosional, paraunconformity or hiatus among them (Al-Safawee, 1982;Al-Mutwali, 1983;Al-Shaibani and Al-Qayim, 1986;Kassab, 1986;Ghafor, 1988;Al-Qayim and Al-Shaibani, 1995;Al-Omari et al, 1994;Awadh et al, 2008;Al-Hadiedi, 2010;Hammoudi, 2011;Al-Mutwali and Al-Doori, 2012;Al-Wazan, 2013;Al-Mutwali and Ibrahim, 2019;Al-Dulaimi and Abdallah, 2019). In contrast, other foraminiferal biostratigraphic studies have supported the occurrence of complete uppermost Maastrichtian deposits (Sharbazheri et al, 2009 and2011;Salih et al, 2013;Mousa et al, 2020;Al Nuaimy et al, 2020). The current high resolution biostratigraphic study aims to prove the occurrence of complete uppermost Maastrichtian deposits throughout the planktic foraminiferal assemblages and its biozonations for the upper part of the Shiranish Formation, Duhok area, Kurdistan Region, North of Iraq.…”

High-resolution biostratigraphic zonation across the Cretaceous/Paleogene (K/Pg) boundary from the Sulaymaniyah area, Kurdistan Region, Northeastern Iraq

“…Basin configuration at the time of the late Cretaceous and early Paleogene resulted in the deposition of different facies at the same time (Jassim and Goff, 2006). As a consequence of this variation a discussion occurred about the boundary between different lithostratigraphic units shows that the occurrence of a complete K/Pg transition in Iraq (Sharbazheri, Ghafor and Muhammed, 2009;Salih, Al-Mutwali and Aldabbagh, 2015;Al-Nuaimy, et al 2020;Mousa, Al-Dulaimi, and Mohammed, 2020;Bamerni, et al, 2021).…”

“…They also stated that the characteristic planktic foraminiferal assemblage of this zone gradually decreased in both species richness and individual numbers from the P. palpebra Zone to the P. hantkeninoides Zone. Mousa, Al-Dulaimi, and Mohammed (2020) recorded the C1 zone in the Western Desert of Iraq and they documented common occurrences of A. intermedius, A. mayaroensis, Glla. pschadae, H. monmouthensis, P. palpebra, R. hexacamerata, the age of this zone estimated by the latest Maastrichtian.…”