RT Book, Section
T1 The Ordovician record of North and West Africa: unravelling sea-level variations, Gondwana tectonics, and the glacial impact
A1 Ghienne, Jean-François
A1 Abdallah, Hussein
A1 Deschamps, Rémy
A1 Guiraud, Michel
A1 Gutiérrez Marco, Juan Carlos
A1 Konaté, Moussa
A1 Meinhold, Guido
A1 Moussa, Abderamane
A1 Rubino, Jean-Loup
A2 Servais, T.
A2 Harper, D. A. T.
A2 Lefebvre, B.
A2 Percival, I. G.
AB The Ordovician of North and West Africa comprises three main transgressive–regressive sequences understood as ‘second-order’ cycles of 10–15 myr duration. Tide- to wave-dominated shallow-marine clastic successions, preserving incidental bryozoan carbonates to the north, include fluvial deposits over the most proximal southern stretches of the platform. The boundary with Cambrian strata remains unclear but the latter are progressively less represented to the south in the undifferentiated ‘Cambro-Ordovician’. To the north, graptolites, brachiopods and trilobites combined with palynomorphs provide a robust biostratigraphic frame. Maximum flooding intervals occurred in the early to middle Tremadocian, middle Darriwilian and middle to late Katian. Two events interfered with an overall long-term transgressive trend. The ‘intra-Arenig’ (late Floian?) tectonic event highlighted palaeohighs coinciding with Paleoproterozoic basements. Gondwanan drainage basins were reorganized, which had an impact on sediment sourcing and distribution of detrital material (e.g. zircons) feeding the pre-Variscan Europe. The second event is the end-Ordovician glaciation. The domain supported the greatest part of the Hirnantian glaciers and may also have preserved pre-Hirnantian glacial archives. It is not until the very latest Ordovician that offshore conditions developed far inland; it is however suspected that this inundation benefited from a transient postglacial isostatic flexure.
PB Geological Society
SN 9781786205896
YR 2023
FD 2023-02-10
LK https://hdl.handle.net/20.500.14352/88415
UL https://hdl.handle.net/20.500.14352/88415
LA eng
NO TotalEnergies
NO BP
NO Sonatrach
NO GDF (Engie)
NO Repsol
NO National Oil Company of Libya
NO Libyan Petroleum Institute
NO BRGM
NO IUGS-UNESCO
NO Ministerio de Ciencia e Innovación
DS Docta Complutense
RD 9 abr 2025