Influence of basement heterogeneity on the architecture of low subsidence rate Paleozoic intracratonic basins (Reggane, Ahnet, Mouydir and Illizi basins, Hoggar Massif)
-
Published:2018-11-07
Issue:6
Volume:9
Page:1239-1275
-
ISSN:1869-9529
-
Container-title:Solid Earth
-
language:en
-
Short-container-title:Solid Earth
Author:
Perron Paul, Guiraud Michel, Vennin Emmanuelle, Moretti Isabelle, Portier Éric, Le Pourhiet LaetitiaORCID, Konaté Moussa
Abstract
Abstract. The Paleozoic intracratonic North African Platform is characterized by an association of arches (ridges, domes, swells, or paleo-highs) and low subsidence rate syncline basins of different wavelengths (75–620 km). The Reggane, Ahnet, Mouydir and Illizi basins are successively delimited from east to west by the Amguid El Biod, Arak-Foum Belrem, and Azzel Matti arches. Through the analysis of new unpublished geological data (i.e., satellite images, well logs, seismic lines), the deposits associated with these arches and syncline basins exhibit thickness variations and facies changes ranging from continental to marine environments. The arches are characterized by thin amalgamated deposits with condensed and erosional surfaces, whereas the syncline basins exhibit thicker and well-preserved successions. In addition, the vertical facies succession evolves from thin Silurian to Givetian deposits into thick Upper Devonian sediments. Synsedimentary structures and major unconformities are related to several tectonic events such as the Cambrian–Ordovician extension, the Ordovician–Silurian glacial rebound, the Silurian–Devonian Caledonian extension/compression, the late Devonian extension/compression, and the Hercynian compression. Locally, deformation is characterized by near-vertical planar normal faults responsible for horst and graben structuring associated with folding during the Cambrian–Ordovician–Silurian period. These structures may have been inverted or reactivated during the Devonian (i.e., Caledonian, Mid–Late Devonian) compression and the Carboniferous (i.e., pre-Hercynian to Hercynian). Additionally, basement characterization from geological and geophysics data (aeromagnetic and gravity maps), shows an interesting age-dependent zonation of the terranes which are bounded by mega-shear zones within the arches–basins framework. The old terranes are situated under arches while the young terranes are located under the basins depocenter. This structural framework results from the accretion of Archean and Proterozoic terranes inherited from former orogeny (e.g., Pan-African orogeny 900–520 Ma). Therefore, the sedimentary infilling pattern and the nature of deformation result from the repeated slow Paleozoic reactivation of Precambrian terranes bounded by subvertical lithospheric fault systems. Alternating periods of tectonic quiescence and low-rate subsidence acceleration associated with extension and local inversion tectonics correspond to a succession of Paleozoic geodynamic events (i.e., far-field orogenic belt, glaciation).
Publisher
Copernicus GmbH
Subject
Paleontology,Stratigraphy,Earth-Surface Processes,Geochemistry and Petrology,Geology,Geophysics,Soil Science
Reference225 articles.
1. Abdelsalam, M. G., Liégeois, J.-P., and Stern, R. J.: The saharan metacraton, J. Afr. Earth Sci., 34, 119–136, 2002. 2. Abdesselam-Rouighi, F.: Etude palynologique du sondage Sebkhet El Melah (unpublished), Entreprise nationale Sonatrach division hydrocarbures direction Laboratiore central des hydrocarbures, Boumerdès, 1977. 3. Abdesselam-Rouighi, F.: Résultats de l'étude palynologiques des sondage Garet El Guefoul Bassin de l'Ahnet-Mouydir (unpublished), Entreprise nationale Sonatrach division hydrocarbures direction Laboratiore central des hydrocarbures, Boumerdès, 1991. 4. Ahmed, A. A.-K. and Moussine-Pouchkine, A.: Lithostratigraphie, sédimentologie et évolution de deux bassins molassiques intramontagneux de la chaine Pan-Africaine: la Série pourprée de l'Ahnet, Nord-Ouest du Hoggar, Algérie, J. Afr. Earth Sci., 6, 525–535, 1987. 5. Aigner, T.: Storm depositional systems: dynamic stratigraphy in modern and ancient shallow-marine sequences, Lect. Notes Earth Sci. Berl. Springer Verl., 3, 1–158, 1985.
Cited by
13 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|