Laffitteina from the Maastrichtian-Thanetian shallow marine carbonates of the Aurès Basin (Northeastern Algeria): microfacies and stratigraphic distribution

Laffitteina de los carbonatos marinos someros del Maastrichtiano-Thanetiano de la cuenca de Aurés (noreste de Argelia): distribución de microfacies y estratigráfica

Sana Benmansour^1,*

¹ Laboratory of Mobilization and Management of Water Resources (LMGRE), University of Batna 2, 53,Constantine Road, Fesdis, 05078, Batna, Algeria.

* Corresponding author: (S. Benmansour ) This email address is being protected from spambots. You need JavaScript enabled to view it.

How to cite this article:

Benmansour, S., 2023, Laffitteina from the Maastrichtian-Thanetian shallow marine carbonates of the Aurès Basin (Northeastern Algeria): microfacies and stratigraphic distribution : Boletín de la Sociedad Geológica Mexicana, 75 (1), A071022. http://dx.doi.org/10.18268/BSGM2023v75n1a071022

Manuscript received: March 22, 2022; Corrected manuscript received: June 6, 2022; Manuscript accepted: July 14, 2022.

ABSTRACT

The Maastrichtian-Thanetian Ncham Member of the Aurès Basin in northeastern Algeria contains variably lenticular microfossils, which are defined as Laffitteina genera. It is a large benthic foraminifera, studied from three stratigraphic sections. The systematic study of Laffitteina led identification of nine species, four of which, Laffitteina marsicana, L. aff. mengaudi, L. monodi and L. erki were recorded for the first time in the study area. Various species of Laffitteina were used as index fossils to recognize the K/Pg transition in the Aurès Basin. The last occurrence of L. oztuerki marks the end of the Maastrichtian, which was found in association with Omphalocyclus macroporus (Lamarck) in the upper Maastrichtian. The first occurrence of L. erki marks the Thanetian age, while the Danian and Selandian deposits are missing in the field after a general emersion in the early Paleocene, despite the absence of a visible non unconformity. It could therefore be proposed that the K/Pg transition may occurs in the last 10 m of the Ncham Member. Concerning the paleoenvironment, Laffitteina is considered as a resistant foraminifera and thrives in meso- to eutrophic environments (lagoon). Microfacies data from the Upper Cretaceous-Lower Paleogene limestones of the Aurès Basin suggests a carbonate platform with shallowing-up sequential organization, mainly controlled by fluctuations in sea-level.

Keywords: Laffitteina, benthic foraminifera, Paleoenvironment, Aurès, Algeria.