A constrained African craton source for the Cenozoic Numidian Flysch: Implications for the palaeogeography of the western Mediterranean basin

Abstract

The provenance of the Numidian Flysch in the western Mediterranean remains a controversial subject which hinders understanding of this regionally widespread depositional system. The Numidian Flysch is a deep marine formation dated as Oligocene to Miocene which outcrops throughout the Maghreb and into Italy. Evidence that is widely used for provenance analysis has not previously been reviewed within the context of the Maghrebian Flysch Basin as a whole. The structural location within the Alpine belt indicates deposition proximal to the African margin, while the uniformity of the Numidian Flysch petrofacies suggests a single cratonic source, in stark contrast to heterolithic and immature flysch formations from the north of the basin. Detrital zircon ages constrain a source region with Pan-African and Eburnian age rocks, unaffected by either Hercynian or Alpine tectonic events, which precludes the European basement blocks to the north of the basin. Palaeocurrent trends which suggest a northern source are unreliable given foreland basin analogues and observed structural complications. An African craton source remains the only viable option once these data are reviewed in their entirety, and the Numidian Flysch therefore represents a major Cenozoic drainage system on the North African margin. Deposition is concurrent with regional Atlas uplift phases, and coincidental with globally cooling climates and high sea levels. The Numidian Flysch is therefore interpreted to represent a highstand passive margin deposit, with timing of deposition controlled primarily by hinterland uplift and climatic fluctuations.

Circum-Tethyan carbonate platform evolution during the Palaeogene: the Prebetic platform as a test for climatically controlled facies shifts

“…We recorded a new section of Ascoy in the SW part of the Prebetic platform and the classical sections of Oneil, Ibi, and Relleu for microfacies and biotic assemblages, comparable to the detailed microfacies analysis by Hoentzsch et al (2011a). In this study, we only present the results of the microfacies and focus on a reinterpretation and comparison with other studies in order to achieve a (2000), Sissingh (2000, 2003), and Thomas et al (2010). coherent platform model with respect to depositional processes, climatic variability, and tectonic impact ( Figure 3).…”

Edough-Cap de Fer Polymetallic District, Northeast Algeria: II. Metallogenic Evolution of a Late Miocene Metamorphic Core Complex in the Alpine Maghrebide Belt

“…Interleaved between the internal massifs and the Tellian nappes is an elongated flysch belt that extends from the Rif to Calabria. This flysch belt comprises a complex of Mesozoic nappes (Kabylian flysch), former cover of an elongated oceanic Tethysian tract (Durand-Delga et al 2000), and the Numidian flysch (Late Oligocene-Burdigalian), deposited on the African margin during opening of the Algeria-Provence oceanic margin (Thomas et al 2010) and incorporated into the nappe pile at the end of the Burdigalian (Bouillin 1979;Sami et al 2010). The Edough-Cap de Fer area in eastern Algeria ( Fig.…”

The Tell-Rif orogenic system (Morocco, Algeria, Tunisia) and the structural heritage of the southern Tethys margin

“…The basin is fed by immature turbiditic sandstones in the internal parts (Guerrera et al, 2005) and ultramature sandstones from the African craton in its external part (Belayouni et al, 2013;Guerrera et al, 2012;Guerrera and Martín-Martín, 2014;Thomas et al, 2010). The question of whether or not the Maghrebian Tethys was floored by an oceanic substratum is still open.…”

“…The Oligocene to Early Miocene sedimentary infill of this basin comprises immature turbiditic sandstones in the north ("Flysch gréso-micacé" of the French authors; Mauretanian Domain) and the mature to ultra-mature sandstones of the famous Numidian Formation to the south (Massylian Domain; see about the "Numidian question", the review by Thomas et al, 2010). It is established that the Mauretanian Domain was sourced from the north, i.e.…”

“…the "Bassin des Flyschs" of the French authors), separating Europe and Iberia from the African plate up to the Miocene (Bouillin et al, 1970;Durand-Delga and Fontboté, 1980;Guerrera and Martín-Martín, 2014 for a review). The flyschs are divided into two units, namely an internal "Mauretanian" unit, whose stratigraphic age spans from Jurassic to Late Miocene, and an external "Massylian" unit including the so-called "Numidian Formation", often detached from its substratum and dated as Late Oligocene to Early Miocene (Guerrera and Martín-Martín, 2014;Thomas et al, 2010). The Massylian unit shows a progressive lateral transition towards the external domains of the South Tethys margin.…”