Mixed marine, brackish water, non-marine, and subaerial microfaunal association in the Red Marls Formation of the Western Aurès Basin (Upper Paleocene)

Authors

  • Raouia Nahnah Institut of Earth Sciences and Universe, Department of Geology, University of Batna 2; Laboratory of Mobilization and Management of Water Resources (LMGRE), University of Batna 2, 53, Constantine Road, 5 Fesdis, 05078, Batna, Algeria. r.nahnah@univ-batna2.dz
  • Sana Benmansour Institut of Earth Sciences and Universe, Department of Geology, University of Batna 2; Laboratory of Mobilization and Management of Water Resources (LMGRE), University of Batna 2, 53, Constantine Road, 5 Fesdis, 05078, Batna, Algeria. s.benmansour@univ-batna2.dz (Corresponding author)

DOI:

https://doi.org/10.4072/rbp.2023.3.05

Abstract

In the western part of the Aurès Basin (northeastern Algeria), the Red Marls of El Kantara Formation records a mixed microfaunal association of non-marine-brackish ostracoda, marine foraminifera, lacustrine charophytes, and subaerial Microcodiums. Based on the recovered biotic component, it is considered that the Red Marls of El-Kantara Formation date from the upper Paleocene (Thanetian). Seven species of brackish water (Neocyprideis raoi) and non-marine ostracoda (Frambocythere tumiensis anjarensis, Paracypretta jonesi, Paracypretta verruculosa, Limnocythere deccanensis, Darwinula torpedo and Zonocypris spirula), have been discovered for the first time in Algeria and on the south Tethyan margin. Paleoenvironmentally, the overall biotic assemblage recovered indicates the presence of a freshwater palustrine/lacustrine depositional system connected to a low energy stream/river. This indicates that marginal marine conditions were prevalent in northeastern Algeria’s far inland regions. Paleobiogeographically, the seven known ostracod species have limited distributions that are until now common only with India. However, this disproved the theory that these species are endemic to the Indian Subcontinent, which is confirmed by their association with cosmopolitan charophytes.

Keywords: limnic ostracoda, charophytes, paleobiogeography, Thanetian, western Aurès, Algeria.

RESUMO – Na parte ocidental da Bacia de Aurès (nordeste da Argélia), a Formação Red Marls de El Kantara registra uma associação
microfaunística mista de ostracodes não-marinhos salobros, foraminíferos marinhos, carófitas lacustres e Microcodiums subaéreos. Com base na biota recuperada, considera-se que a Formação Red Marls de El Kantara data do Paleoceno superior (Tanetiano). Sete espécies de água salobra (Neocyprideis raoi) e ostracodes não-marinhos (Frambocythere tumiensis anjarensis, Paracypretta jonesi, Paracypretta verruculosa, Limnocythere deccanensis, Darwinula torpedo e Zonocypris spirula) foram descobertas pela primeira vez na Argélia e na margem sul do Tethys. Paleoambientalmente, a associação geral recuperada indica a presença de um sistema deposicional palustre/lacustre de água doce conectado a um córrego/rio de baixa energia. Isso indica que as condições marinhas marginais eram predominantes nas regiões interiores do nordeste da Argélia. Paleobiogeograficamente, as sete espécies conhecidas de ostracodes têm distribuição limitada, até agora comuns apenas com a Índia. No entanto, isso refutou a teoria de que essas espécies são endêmicas do subcontinente indiano, o que é confirmado por sua associação com carófitas cosmopolitas.

Palavras-chave: ostracoda límnicos, carófitas, paleobiogeografia, Tanetiano, Aurès ocidentais, Argélia.

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Published

2023-10-23

How to Cite

Nahnah, R., & Benmansour, S. (2023). Mixed marine, brackish water, non-marine, and subaerial microfaunal association in the Red Marls Formation of the Western Aurès Basin (Upper Paleocene). Revista Brasileira De Paleontologia, 26(3), 197–211. https://doi.org/10.4072/rbp.2023.3.05