Geometry and structural evolution of Lorbeus diapir, northwestern Tunisia: polyphase diapirism of the North African inverted passive margin

2014 ◽  
Vol 103 (3) ◽  
pp. 881-900 ◽  
Author(s):  
Amara Masrouhi ◽  
Olivier Bellier ◽  
Hemin Koyi
Keyword(s):  
Structural Evolution ◽  
Passive Margin ◽  
North African ◽  
The North

The structuration of the External Rif (Rif belt: Northern Morocco). An insights from paleo-thermal and structural analyses

2021 ◽  
Author(s):  
Achraf Atouabat ◽  
Sveva Corrado ◽  
Dominique Frizon de Lamotte ◽  
Geoffroy Mohn ◽  
Faouziya Haissen ◽  
...  
Keyword(s):  
Upper Cretaceous ◽  
Vitrinite Reflectance ◽  
Structural Evolution ◽  
Structural Data ◽  
Passive Margin ◽  
Thermal Maturity ◽  
North African ◽  
Tectonic Structures ◽  
The North ◽  
Rif Belt

<p>Belonging to the Maghrebides system, the Rif belt (Northern Morocco) suffered an important Cenozoic Alpine compressional deformation as a consequence of the closure of the Maghrebian Tethys and the westward translation and docking of the Alboran Domain onto the African margin during the Late Burdigalian. The Mesozoic North African Margin is still partially preserved in the Eastern Rif (e.g., Senhadja Jurassic-Cretaceous unit) and inverted in its Central portion (North of the Nekor Fault Zone) due to the high shortening in this area. It is in agreement with sub-surface data suggesting that the thickest crust along the chain is located in the central Rif (Izzaren Area, External Rif), and can be interpreted as a deep-rooted crustal imbrication.</p><p>This contribution aims to characterize the role of the structural inheritance of the rifted North African margin in the development and the propagation of the Rif belt by the combination of paleothermal and structural data collected along a NE-SW regional transect (between Chefchaouen and Ouezzane provinces), focusing mainly on the external zones (namely, Intrarif, Mesorif and Prerif) sampling the deformed domains originally developed along the North African paleo-passive margin. A new paleo-thermal dataset of vitrinite reflectance (Ro%), micro-Raman spectroscopy on organic matter and XRD on clayey fraction of sediments displays levels of thermal maturity between early and deep diagenetic conditions (Ro% from 0.49% to 1.15%). The highest thermal maturity values along the section are concentrated in the Lower to middle Cretaceous Loukkos Intrarifain sub-unit that is structurally squeezed between Tangier Intrarif Upper Cretaceous sub-unit and the Mesorif “Izzaren Duplex”. It attests for an important amount of shortening leading to the development of an imbricate fan of thrusts.</p><p>The geometry of the “Izzaren Duplex”, limited at surface by two first-order thrust faults, is controlled by pre-existing tectonic structures, probably inherited by the former architecture of the North African paleomargin. Moreover, the Chattian-Middle Miocene siliciclastic succession filling the Zoumi basin is in a stratigraphic continuity with the Izzaren Upper Jurassic-Upper Cretaceous substratum, sheding new light on its geodynamic meaning. This observation is supported by the homogeneity of deformation and the absence of thermal jump between the Mesozoic and Cenozoic successions, attesting for an active compressive deformation in the area between the Late Serravalian and Late Tortonian.</p><p>In conclusion, the combination of paleo-thermal and structural analysis allowed to reconstruct robust tectono-thermal model in order to propose an accurate reconstruction of the structural evolution and a new geological restoration of the Rif belt with respect to the geometry of the rifted paleo-margin.</p>

Structural styles of the External Rif and Flysch Domain (Rif belt, northern Morocco) through thermal maturity and structural data

2020 ◽  
Author(s):  
Andrea Schito ◽  
Achraf Atouabat ◽  
Sveva Corrado ◽  
Faouziya Haissen ◽  
Geoffroy Mohn ◽  
...  
Keyword(s):  
Vitrinite Reflectance ◽  
Methodological Approach ◽  
Structural Evolution ◽  
Structural Data ◽  
Thermal Modelling ◽  
Thermal Maturity ◽  
North African ◽  
Data Set ◽  
The North ◽  
Rif Belt

<p>Located in northern Morocco, the Rif belt represents the western edge of the Maghrebides system. This domain underwent a significant Cenozoic alpine compressional deformation, due to the collision between the North African margin and the south-western margin of the exotic Alboran Domain. This collision led to the development of a nappe stack during the Miocene.</p><p>This contribution aims to characterize the main tectonic mechanisms driving the evolution of the Rifain wedge, its burial-exhumation paths and to understand the former architecture of the North African paleo-margin. The work focuses mainly on the Flysch domain, originated from the Maghrebian branch of the Tethys and on the External domain (namely Intrarif, Mesorif and Prerif) that belong to the former north African margin. To define the thrust sheet stacking pattern and their burial-exhumation paths, a regional transect from Chefchaouen and Ouezzane towns (Central Rif), crossing the orogenic wedge from the Flysch to the Prerif Units is constructed.</p><p>The methodological approach consists in combining petrography and Raman micro-spectroscopy on organic matter and 1D thermal modelling, together with field structural data.</p><p>A new paleo-thermal data set of vitrinite reflectance (Ro%) and Raman micro-spectroscopy displays levels of thermal maturity between early and deep diagenetic conditions (Ro% ranges from 0.50% to 1.15%).</p><p>Preliminary results show an abrupt change in the thermal maturity and the rate of shortening in the Loukkos sub-unit (Intrarif Domain) that is structurally squeezed between Tangier sub-unit (Intrarif Domain) and the “Izzaren Duplex” (Mesorif).</p><p>Furthermore, previous studies show that the thickest crust below the Rif fold-and-thrust belt is located below the Izzaren area, suggesting a deep crustal imbrication at the transition between the Intrarif and the Mesorif. These observations joined with the thermal maturity data and 1D thermal modelling allow revisiting the structural evolution of the central part of the Rif belt, by defining the rate of shortening and proposing a new geological restoration with respect to the Mesozoic North African margin structural original setting.</p>

The evolution of the Lansarine–Baouala salt canopy in the North African Cretaceous passive margin in Tunisia

2013 ◽  
Vol 150 (5) ◽  
pp. 835-861 ◽  
Author(s):  
AMARA MASROUHI ◽  
OLIVIER BELLIER ◽  
HEMIN KOYI ◽  
JEAN-MARIE VILA ◽  
MOHAMED GHANMI
Keyword(s):  
Geological Mapping ◽  
Passive Margin ◽  
Normal Faults ◽  
North African ◽  
The North ◽  
Extensional Tectonic ◽  
Two Factors ◽  
Salt Structure ◽  
Differential Sedimentation ◽  
Cretaceous Period

AbstractDetailed geological mapping, dating, and gravimetric and seismic data are used to interpret the Lansarine–Baouala salt structure (North Tunisia) as a salt canopy emplaced during the Cretaceous Period. The extensional tectonic regime related to the Cretaceous continental margin offered at least two factors that encouraged buried Triassic salt to extrude onto the sea floor and flow downslope: (i) extension induced normal faults that provided routes to the surface, and led to the formation of sub-marine slopes along which salt could flow; (ii) this structural setting led to differential sedimentation and consequently differential loading as a mechanism for salt movement. The present 40-km-long Lansarine–Baouala salt structure with its unique mass of allochthonous Triassic salt at surface was fed from at least four stems. The salt structure is recognized as one of the few examples worldwide of a subaerial salt canopy due to the coalescence of submarine sheets of Triassic salt extruded in Cretaceous times.

New ophiolite slivers in the External Rif belt, and tentative restoration of a dual Tethyan suture in the western Maghrebides

2014 ◽  
Vol 185 (5) ◽  
pp. 313-328 ◽  
Author(s):  
André Michard ◽  
Abdelkader Mokhtari ◽  
Ahmed Chalouan ◽  
Omar Saddiqi ◽  
Philippe Rossi ◽  
...  
Keyword(s):  
Oceanic Crust ◽  
Suture Zone ◽  
Passive Margin ◽  
Transform Fault ◽  
North African ◽  
Structural Position ◽  
Passive Margins ◽  
The Core ◽  
The North ◽  
Rif Belt

AbstractOphiolite slivers have been described recently in the core of the External zones of the Central Rif belt. The present work aims at illustrating new ophiolite slivers further east and discussing the structural position and tectonic emplacement of all these oceanic floor remnants. Their basement consists of gabbros previously dated at 166±3 Ma and their cover includes mafic breccias, micrites and radiolarites. These oceanic slivers are located within the Mesorif nappe stack at the bottom of the Senhadja nappe that roots beneath the Intrarif Ketama unit and was thrust over the more external Mesorif and Prerif units during the Cenozoic inversion of the North African paleomargin. These oceanic crust (OC) slivers belong to the same Mesorif suture zone as the Beni Malek serpentinites and Ait Amrâne metabasites from eastern Rif that also include marbles with ophiolitic clasts and derive from an ocean-continent transition (OCT) domain. After examination of the varied hypotheses that have been suggested to account for the emplacement of these units in the External Rif, we propose that obduction sampled an oceanic corridor opened between the Mesorif and Intrarif domains at the emplacement of the Rif Triassic evaporite basin. The Intrarif block should have been then separated from the African passive margin and connected with the Flysch domain south of the passive margin of the Alboran domain. The pre-collision structure of the Rif transect would involve two hyper-extended passive margins separated by a narrow oceanic transform fault corridor. Therefore the Tethys suture in the western Maghrebides would be split by the Intrarif block and would involve the Flysch zone in the north and the ophiolite bearing Mesorif suture zone in the south.

Active transcurrent fault system along the north African passive margin

1987 ◽  
Vol 141 (1-3) ◽  
pp. 249-260 ◽  
Author(s):  
Zvi Ben-Avraham ◽  
Amos Nur ◽  
Cello Giuseppe
Keyword(s):  
Passive Margin ◽  
Fault System ◽  
North African ◽  
The North ◽  
Transcurrent Fault

HALF-GRABEN MODEL FOR THE STRUCTURAL EVOLUTION OF THE FITZROY TROUGH, CANNING BASIN, AND IMPLICATIONS FOR RESOURCE EXPLORATION

1988 ◽  
Vol 28 (1) ◽  
pp. 76 ◽  
Author(s):  
B.J. Drummond ◽  
M.A. Etheridge ◽  
P.J. Davies ◽  
M.F. Middleton
Keyword(s):  
Structural Evolution ◽  
Passive Margin ◽  
Normal Faults ◽  
Canning Basin ◽  
North East ◽  
The North ◽  
Structural Style ◽  
Half Graben ◽  
Resource Exploration ◽  
Transfer Faults

The Fitzroy Trough is a north-west/south-east trending rift along the north-east margin of the Canning Basin. The major crustal extension in the trough occurred in the Middle Devonian to Early Carboniferous. Most idealised cross-sections show down-to-trough normal faults bounding both sides of the trough. In contrast, we show the trough to have a half- graben style, with one side a hinge zone or flexure, and the other side bounded by normal faults. Thus, the basin has marked structural asymmetry. The sense of asymmetry switches several times along strike with the hinged margin on the north-eastern margin in some places and the south-west margin in others. The switching in asymmetry occurs at transfer faults. This structural style is expected in extensional tectonic models where the extension occurs on a detachment surface and is typical of many continental and passive margin rifts. The asymmetry of the Palaeozoic structure has implications for resource exploration because of its influence on facies development in and subsequent structural evolution of the trough. Quite different syn-rift clastic and carbonate facies are expected on faulted and hinged margins of a half-graben. Post-rift subsidence will also be somewhat asymmetric, influencing the carbonate reef geometry in particular. Mesozoic deformation in the basin reactivated many of the Palaeozoic normal and transfer faults, and induced reverse slip up basement surfaces on the hinged margin segments.

Skeletochronology and mark–recapture assessments of growth in the North African agamid lizard (Agama impalearis)

1999 ◽  
Vol 249 (4) ◽  
pp. 455-461
Author(s):  
El Hassan El Mouden ◽  
Mohammed Znari ◽  
Richard P. Brown
Keyword(s):  
North African ◽  
Mark Recapture ◽  
Agamid Lizard ◽  
The North

scholarly journals Defatted Hydroethanolic Extract of Ammodaucus leucotrichus Cosson and Durieu Seeds: Antidiabetic and Anti-Inflammatory Activities

2020 ◽  
Vol 10 (24) ◽  
pp. 9147
Author(s):  
Imane Es-Safi ◽  
Hamza Mechchate ◽  
Amal Amaghnouje ◽  
Anna Calarco ◽  
Smahane Boukhira ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Fasting Blood Glucose ◽  
Diabetic Mice ◽  
North African ◽  
Glucose Levels ◽  
The North ◽  
Blood Glucose Levels ◽  
Anti Inflammatory ◽  
Hydroethanolic Extract ◽  
Inflammatory Effect

The seeds of Ammodaucus leucotrichus Cosson and Durieu have been used in the North African Sahara as a traditional medicine to treat diabetes. The present study investigates the antidiabetic, antihyperglycemic, and anti-inflammatory properties of the defatted hydroethanolic extract of Ammodaucus leucotrichus (DHEAM). The antidiabetic and the antihyperglycemic studies were assessed on alloxan-induced diabetic with orally administered doses of DHEAM (100 and 200 mg/kg). At the same time, its anti-inflammatory propriety was evaluated by measuring edema development in the Wistar rats paw induced with carrageenan. Treatment of diabetic mice with DHEAM for four weeks managed their high fasting blood glucose levels, improved their overall health, and also revealed an excellent antihyperglycemic activity. Following the anti-inflammatory results, DHEAM exhibited a perfect activity. HPLC results revealed the presence of seven molecules (chlorogenic acid, 3-p-coumaroylquinic acid, gallic acid, ferulic acid, myricetin, quercetin, luteolin). This work indicates that the DHEAM has an important antidiabetic, antihyperglycemic, and anti-inflammatory effect that can be well established as a phytomedicine to treat diabetes.

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