Cretaceous paleomargin tilted blocks geometry in northern Tunisia: stratigraphic consideration and fault kinematic analy
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AGIC 2017
Cretaceous paleomargin tilted blocks geometry in northern Tunisia: stratigraphic consideration and fault kinematic analysis Chahreddine Naji 1,2 & Amara Masrouhi 3 & Zayneb Amri 1,2 & Mohamed Gharbi 1 & Olivier Bellier 4 Received: 14 March 2018 / Accepted: 20 September 2018 / Published online: 2 October 2018 # Saudi Society for Geosciences 2018
Abstract New stratigraphic data, lithostratigraphic correlations, and fault kinematic analysis are used to discuss the basin geometry and sedimentation patterns of the northeastern Tunisia during Cretaceous times. Significant facies and thickness variations are deduced along the northeastern Atlas of Tunisia. The NW-SE 80-km-long regional correlation suggests a high sedimentation rate associated with irregular sea floor. The fault kinematic analysis highlights N-S to NE-SW tectonic extension during Early Cretaceous. During Aptian–Albian times, an extensional regime is recognized with NE-SW tectonic extension. The Cenomanian–Turonian fault populations highlight a WNW-ESE to NW-SE extension, and Campanian–Maastrichtian faults illustrate an NW-SE extension. The normal faulting is associated to repetitive local depocenters with a high rate of sedimentation as well as abundant syntectonic conglomeratic horizons, slump folds, and halokinetic structures. The sequence correlation shows repetitive local depocenters characterizing the basin during Early Cretaceous times. All the above arguments are in favor of basin configuration with tilted blocks geometry. This geometry is shaped by major synsedimentary intra-basin listric normal faults, themselves related to the extensional setting of the southern Tethyan paleomargin, which persisted into the Campanian– Maastrichtian times. The results support a predominant relationship between tilted blocks geometry and sedimentation rather than E-W BTunisian trough^ as it was previously accepted. Keywords Cretaceous . Tilted blocks . Stratigraphic consideration . Fault kinematic . Tunisia
Introduction The present-day structure of the Northern African margin in Tunisia results from a complex tectonic evolution that operated since Late Permian with the beginning of the breakup of Pangea and ended with the Cenozoic Alpine orogeny of the
This article is part of the Topical Collection on Geology of North Africa and Mediterranean Regions * Chahreddine Naji [email protected] 1
Geo-Resources Laboratory, Water Research and Technologies Center Borj-Cedria, Soliman, Tunisia
2
Faculté des Sciences de Bizerte, Université de Carthage, Bizerte, Tunisia
3
Department of Geo-exploration Techniques, Faculty of Earth Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
4
CNRS, IRD, INRA, Coll France, CEREGE, Aix Marseille University, Aix-en-Provence, France
Maghrebide chain. The geodynamic evolution of the northern margin of Africa has been characterized by extension, crustal stretching and thinning, as well as subsidence during the Mesozoic Tethyan rifting (Boughdiri et al. 2007; Gharbi et al. 2013; El Amari et al. 2016; Sous
