Abstract

This study investigates the provenance, weathering history, and tectono-sedimentary evolution of lower Ediacaran siliciclastic rocks of the Imiter Formation (Saghro Group, Imiter Sub-inlier, Anti-Atlas, Morocco) deposited along the northern margin of Gondwana. An integrated approach combining petrography, whole-rock major and trace element geochemistry, rare earth elements (REEs), Sm–Nd isotopes, and organic geochemistry (TOC and δ13Corg) was used to constrain sediment sources and depositional conditions. Geochemical proxies, including Th/Sc, La/Sc, and Zr/Sc ratios, together with REE distribution patterns, indicate that the sediments were mainly derived from felsic-to-intermediate rocks of the upper continental crust, with only minor sediment recycling. The negative εNd(t) values (−8.5 to −6.2) and Paleoproterozoic Nd model ages (1.6–2.1 Ga) further suggest the erosion of evolved crustal sources related to the West African Craton. Weathering indices (CIA, CIW, PIA) suggest weak-to-moderate chemical weathering under predominantly arid conditions. Redox-sensitive proxies (V–Ni, V/Cr, V/(V + Ni)) and low TOC content (0.1–0.3 wt.%) indicate deposition under mainly oxic-to-dysoxic conditions, with only transient reducing episodes. Tectonic discrimination diagrams, supported by regional magmatism, point to sedimentation within an extensional basin evolving from active-margin to continental rift conditions during the late Pan-African orogeny. The Imiter Formation records a system dominated by crustal recycling, syn-rift tectonics, and dynamic redox conditions in a shallow marine environment.

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