Styles of Salt Tectonics in Central Tunisia

Troudi, H.; Tari, Gábor; Alouani, Wael; Cantarella, G.

doi:10.1016/b978-0-12-809417-4.00026-4

Cited by 20 publications

(11 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, for modelling purposes, the salt layer is here approximated as temperature-independent, mechanically uniform viscous material with a linear (Newtonian) stress-strain rate behaviour This condition might be true for wet salt (> ∼ 0.05 wt % water content) with relatively small grain sizes (< 0.5 mm) (Urai et al, 2008). Under this assumption, differential (viscous) stress is calculated by (Weijermars et al, 1993;Bonini et al, 2012;Turcotte and Schubert, 2014)…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Contribution of gravity gliding in salt-bearing rift basins – a new experimental setup for simulating salt tectonics under the influence of sub-salt extension and tilting

et al. 2021

View full text Add to dashboard Cite

Abstract. Basin-scale salt flow and the evolution of salt structures in rift basins is mainly driven by sub- and supra-salt faulting and sedimentary loading. Crustal extension is often accompanied and followed by thermal subsidence leading to tilting of the graben flanks, which might induce an additional basinward-directed driver for salt tectonics. We designed a new experimental analogue apparatus capable of integrating the processes of sub-salt graben extension and tilting of the flanks, such that the overlapping effects on the deformation of a viscous substratum and the brittle overburden can be simulated. The presented experimental study was performed to demonstrate the main functionality of the experimental procedure and setup, demonstrating the main differences in structural evolution between conditions of pure extension, pure tilting, and extension combined with tilting. Digital image correlation of top-view stereoscopic images was applied to reveal the 3D displacement and strain patterns. The results of these experiments suggest that in salt basins affected by sub-salt extension and flank inclination, the salt flow and downward movement of overburden affects the entire flanks of the basin. Supra-salt extension occurring close to the graben centre is overprinted by the downward movement; i.e. the amount of extension is reduced or extensional faults zones are shortened. At the basin margins, thin-skinned extensional faults developed as a result of gravity gliding. A comparison with natural examples reveals that such fault zones can also be observed at the margins of many salt-bearing rift basins indicating that gravity gliding played a role in these basins.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Tectonic extension induces a Couette shear flow (Turcotte and Schubert, 2014) at the base of the silicone on the flanks.…”

Section: Discussionmentioning

confidence: 99%

Contribution of gravity gliding in salt-bearing rift basins – a new experimental setup for simulating salt tectonics under the influence of sub-salt extension and tilting

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The Tunisian Tell and Atlas has been considered for decades as a paradigmatic region for the study of diapiric structures in an external foreland thrust belt (e.g., Amri et al., 2020; Ayed‐Khaled et al., 2015; Bedir et al., 2001; Ben Chelbi et al., 2006; Melki et al., 2010; Perthuisot, 1981; Troudi et al., 2017; Vila, 1995). Diapiric intrusions of Triassic evaporites are interpreted as related to Cretaceous rifting of the North Maghrebian passive margin, extruding to the surface as thousand km 2 large salt glaciers or canopies (Amri et al., 2020; Ayed‐Khaled et al., 2015; Ghanmi et al., 2001; Masrouhi & Koyi, 2012; Masrouhi et al., 2014; Vila, 1995; Vila et al., 1996; Zouaghi et al., 2013).…”

Section: Geological Settingmentioning

confidence: 99%

Metamorphic Domes in Northern Tunisia: Exhuming the Roots of Nappe Belts by Widespread Post‐Subduction Delamination in the Western Mediterranean

et al. 2023

View full text Add to dashboard Cite

Cenozoic extension in the Western Mediterranean has been related to the dynamics of back-arc domains. Although, in most of its orogenic belts extension propagated into the fore-arc nappe domains. Here we revisit the structure, metamorphism and radiometric ages of the Tunisian Tell, where HP/LT rocks (350°C at 0.8 GPa), were exhumed by the sequential activity of extensional detachments after heating and decompression (410°C-440°C at 0.6-0.3 GPa) in a plate convergent setting. Normal faults thinning the Tunisian Tell detached at two different crustal levels. The shallower one cuts down into the Atlas Mesozoic sequence, involving Tellian Triassic evaporites in the hanging-wall forming halokinetic structures in the Mejerda basin late Miocene. The deeper-detachment bounds metamorphic domes formed by marbles and metapsammites from the Atlas domain. Illite crystallinity on Triassic rocks shows epizonal to anchizonal values, at deep and intermediate structural depths of the Tell-Atlas nappe belt, respectively. New U-Pb 49.78 ± 1.28 Ma rutile ages from Tellian metabasites, together with existing phlogopite 23-17 Ma K-Ar ages in Atlas marbles from the footwall of the deepest detachment, indicate a polymetamorphic evolution. The Tell rocks underthrusted the Kabylian flysch in the early Eocene. Further, early Miocene shortening thrusted the metabasites over lower-grade sediments, producing HP/LT metamorphism and ductile stretching at the base of the Atlas belt. The exhumation of midcrustal roots of Western Mediterranean nappe belts after tectonic shortening is a common feature related to tearing at the edges of the subduction systems and inboard delamination of their subcontinental lithospheric mantle.Plain Language Summary Mountain belts are formed by shortened sedimentary rocks. The Tell cordillera in Northern Tunisia is interpreted as a classic mountain belt developed through protracted shortening from the late Cretaceous until Present, formed by folded and overthrusted rocks, and intruded by salt bodies. However, we show here that conversely, some of the supposed salt bodies are formed by metamorphic rocks that were originally buried at depths of approximately 26 km. Moreover, the remaining salt structures in the Tunisian Tell formed in relation to the late-stage thinning and collapse of the mountain belt, as they intrude through extensional faults into late Miocene sediments. We characterize the temperature and pressure conditions reached by the metamorphic rocks and obtain a 49 Ma age of an early metamorphic event by radiometric dating of rutile. Metamorphic rocks where also exhumed in other Western Mediterranean mountain belts like the Betics, Rif, Algerian Tell after the main shortening stage. We relate this process to delamination, a deep mantle tectonic mechanism, which strips the nappe belt crustal domain from its underlying mantle root.BOOTH REA ET AL.

show abstract

“…Over the last three decades, several studies have focused on different salt structures, including salt glaciers, large evaporitic allochthonous sheets and salt canopies in Northwestern Africa (e.g., Perthuisot et al, 1998;Troudi et al, 2017;Benassi et al, 2006;Masrouhi et al, 2014b;Masrouhi and Koyi, 2012;Dhahri and Boukadi, 2017;Ghanmi et al, 2001;Ben Chelbi et al, 2006;Vila et al, 2002;Ghanmi et al, 2006;Masrouhi et al, 2013;Vergés et al, 2017;Amine et al, 2020;). Recently, a link between a salt diapir and an allochthonous salt sheet was identified in the northern Atlas of Tunisia (Amri et al, 2020).…”

Section: Evolution Of Beassmentioning

confidence: 99%

Mechanical relationship between strike-slip faulting and salt tectonics in the Northern Tunisian Atlas: The Bir-El-Afou salt structure

Amri

Masrouhi

Naji

et al. 2022

Journal of Structural Geology

View full text Add to dashboard Cite

Styles of Salt Tectonics in Central Tunisia

Cited by 20 publications

References 26 publications

Contribution of gravity gliding in salt-bearing rift basins – a new experimental setup for simulating salt tectonics under the influence of sub-salt extension and tilting

Contribution of gravity gliding in salt-bearing rift basins – a new experimental setup for simulating salt tectonics under the influence of sub-salt extension and tilting

Metamorphic Domes in Northern Tunisia: Exhuming the Roots of Nappe Belts by Widespread Post‐Subduction Delamination in the Western Mediterranean

Mechanical relationship between strike-slip faulting and salt tectonics in the Northern Tunisian Atlas: The Bir-El-Afou salt structure

Contact Info

Product

Resources

About