The Bou-Azzer glaciation: Evidence for an Ediacaran glaciation on the West African Craton (Anti-Atlas, Morocco)

Geology and Metallogenesis of the Sediment-Hosted Cu-Ag Deposit of Tizert (Igherm Inlier, Anti-Atlas Copperbelt, Morocco)

“…This formation, which rests unconformably upon the D1-folded PanAfrican assemblages, was tilted, faulted, and folded during the Pan-African D2 compressional event, with development of axial-planar cleavage (Figure 3(a)). The Tiddiline Formation displays in the Bou Azzer and Igherm inliers eroded surfaces and striated quartzitic pebbles related to glacial erosion [31]. Subsequent active extensional faulting associated with postorogenic collapse led to deposition of up to 2000 m of volcanic, volcaniclastic, and conglomeratic rocks of the Upper Ediacaran Ouarzazate Group (≈600-560 Ma; [32,33]).…”

Sedimentary imprints of former ice-sheet margins: Insights from an end-Ordovician archive (SW Libya)

“…The stars indicate the importance of each structure for the identification of ice-margin settings (i.e., one star: low significance; two stars: good significance; three stars: strong significance). Mory et al, 2008;Rocha-Campos et al, 2008), endOrdovician Ghienne, 2004, 2005;Clark-Lowes, 2005;Denis et al, 2007a) and Neoproterozoic (Deynoux, 1985;Vernhet et al, 2012) successions. Based on the end-Ordovician record in the Djado area (Niger), Denis et al (2010) proposed a comprehensive deformation model where cyclic modifications of fluid pressure at the ice/bed interface resulted in small-to meso-scale subglacial shear deformation structures formed at the top, and within a subglacial sediment pile, both constituting the shear zone.…”

Guía de campo post-congreso, 21-24 de Octubre de 2019: Ediacárico y Terreneuviense en los alrededores del Geoparque de la UNESCO Villuercas-Ibores-Jara

“…Palaeogeographically, these glaciomarine diamictites and related sedimentary deposits lie on the periphery of the West African craton (western peri-Gondwana), evidence provided by detrital zircon U-Pb ages and their Hf isotope composition (Linnemann et al, 2018). Correlation with similar glaciomarine deposits in the Anti-Atlas (Bou Azzer inlier; Vernhet et al, 2012) and Arabia (Vickers-Rich et al, 2012) suggests a continued distribution of post-Gaskiers glacial deposits along the Gondwana margin of Northern Africa. The Weesenstein-Orellana Glaciation correlates with the Shuram-Wonoka δ 13 C anomaly.…”

“…Age constraints completely rule out a correlation of this glacial event recorded in the Cadomian metasedimentary rocks with the Gaskiers glaciation, which occurred around 579-581 Ma (Bowring et al, 2002, Thompson et al, 2014Pu et al, 2016). Instead, a correlation with a glacial event recorded in Northwest Africa (Morocco) (Vernhet et al, 2012) and in Arabia (Vickers-Rich et al, 2012) is much more realistic and provides information about the timing of this young Neoproterozoic glacial (2012) describe glaciomarine structures (striated pavement on rhyolites) within the Ouarzazate group. The age of the latter is constrained by published U-Pb ages of the Ouarzazate Supergroup and can be placed in a time window between ca.…”