New paleomagnetic data (43 sites) from Mesozoic sediments are contributed in this work, verifying the presence of a pervasive syntectonic Early Cretaceous remagnetization in the easternmost area of ...the Moroccan High Atlas. Using the small circle intersection method, we have calculated the characteristic remagnetization direction (Dec: 337.3, Inc: 38.4) that fits with a 100‐Ma age, according to the Apparent Polar Wander Path of Africa. The paleomagnetic vectors of remagnetization are used to obtain the geometry during the remagnetization stage (100 Ma) of one of the most renowned geological cross sections of the High Atlas, the Midelt‐Errachidia profile. The partial restoration of the cross section at 100 Ma allows us to determine the dips of the beds at the remagnetization stage in five structures (ridges or anticlines). Our results indicate that the five ridges that configure the Midelt‐Errachidia profile were initiated to different degrees prior to wholesale compressive deformation during the Cenozoic. This configuration can be explained according to two different scenarios that we discuss in this paper: transpression and diapirism. The geological model obtained, both at present and at 100 Ma, indicates the existence of a Mesozoic cover substantially décolled from the Paleozoic basement, what strongly contrasts with previously published transects of the same area.
Key Points
A widespread Albian‐Cenomanian remagnetization affecs the Mesozoic sediments of the Central High Atlas, Midelt‐Errachidia cross section
Restoration of syn‐tectonic remagnetization allows obtaining the geometry of the basin at the age of the remagnetization
We provide four detailed restored cross sections at 100 Ma considering two different scenarios, transpression, and diapirism
Positive tectonic inversion of sedimentary basins has been recognized as one of the primary mechanisms of mountain building and intraplate deformation. Reconstructing the tectonic history of basins ...is relatively easy for the inversion stage but becomes more difficult for the basinal stage, especially when strong deformation involving cleavage development is associated with the subsequent compressional tectonics. Since tectonic markers for the extensional episodes are not commonly well developed, Anisotropy of Magnetic Susceptibility (AMS) has provided recently a tool for analyzing early stages in the evolution of sedimentary basins, even in the absence of other outcrop-scale mesostructures. Here, we expose and discuss the applicability of magnetic fabrics (by means of AMS) to different types of intra-plate sedimentary basins in the Western Tethys region formed under extensional or transtensional regimes and which underwent different inversion styles (total or partial inversion, with or without cleavage development, forming part of compressional thrust sheets, etc.) owing to specific particular p-T conditions and structural controls. Factors such as lithology, magnetic mineralogy, position within the sedimentary pile and deformation intensity are key to interpret the obtained magnetic fabrics in terms of tectonic evolution. A basin classification is proposed according to inversion styles and magnetic fabrics: Where inversion did not involve cleavage development, magnetic lineation is parallel to the stretching direction corresponding to the extensional stage. The transition between non-cleaved to inversion-related cleaved units is marked by the switch of magnetic lineations from parallel to extension to parallel to the intersection lineation between cleavage and bedding. These relationships are enhanced when extension and compression are roughly coaxial, then favoring the clustering of axes of the magnetic ellipsoid. Even when extreme inversion occurs and the early, extensional fabric is obliterated, magnetic fabrics provide information about the interaction between preferred deformation directions associated with the main stages in basin evolution.
•Contribution of Anisotropy of Magnetic Susceptibility to the evolution of inverted sedimentary basins•Proposal of basin classification according to inversion modes and magnetic fabrics•From Mesozoic rifting and transtension to Cenozoic compression in intraplate basins of the western Tethys•Magnetic mineralogy, inversion degree and extension/compression coaxiality as constraints for magnetic fabrics.
The purpose of this work is to use paleomagnetic data to determine the tectonic evolution of the inverted High Atlas basin in the area of the Taguelft syncline. This syncline shows two well defined ...rock types of Jurassic age: marly limestones and red beds, and therefore provides the opportunity of comparing paleomagnetic results from rocks with different magnetic mineralogy. Forty-three sites, in an area of 250 km2 were the subject of a paleomagnetic and rock magnetic study. Both lithologies display a stable interfolding remagnetization, alternatively carried by magnetite in marly-limestones and hematite in red beds. The small circle intersections (SCI) method applied separately to the mean directions of the two rock types indicate a synchronous record of remagnetization, that can be dated as Mid-Cretaceous (100 Ma) by comparing the direction (SCI) with the expected directions obtained from the Global Apparent Wander Path in African coordinates. Small circle techniques were used to reconstruct the syncline geometry at the remagnetization time. Paleodips quantification reveals that this area behaved as an extension-related mini-basin, with strong control by salt migration, before and during the sedimentation of Bathonian red beds.
•Application of paleomagnetism to investigate evolution of the Taguelft mini-basin.•NRM of Jurassic marly-limestones and red beds is dominated by a synfolding remagnetization acquired arround 100Ma and pre-dates the atlasic inversion events.•Two stages of folding are revealed from paleomagnetism and structural analysis.•The first stage is extensional and the second one is linked to basin inversion during the Cenozoic.•The paleogeometry of the Taguelft mini-basin is reconstructed using paleomagnetic data.
Medical education worldwide is undergoing a pedagogical renovation movement; medical simulation is one of the revolutionary educational tools whose aim is to improve the medical knowledge, technical ...and non-technical skills of health professionals, while ensuring patient safety. Many studies have dealt with the contribution of simulation in cardiology, however no studies have been done on the management of cardiovascular emergencies in pregnant women by simulation. The purpose of our work is to evaluate a simulation-based educational training program on cardiovascular emergencies in pregnant women by comparing it to a “traditional” training program and to assess the students’ satisfaction with this teaching method.
We conducted anexperimental, comparative, randomized and multicentric studyon 60 medical students (≥6th year), the study started with a pre-test, followed by a theoretical training session on cardiovascular emergencies in pregnant women, a randomization of students into two groups, according to whether they had benefited or not from simulation sessions before taking a post-test.
We selected 57 students: 29 in group 1 (SIM+) and 28 in group 2 (SIM−), both groups were comparable regarding their level of medical studies, hospital training in cardiology or gynecology and prior participation at simulation sessions. The pre-test results were comparable for both training groups. The progression of the marks between the pre-test and the post-test was significant P<0.001 for both training groups, However a better progression of the marks in group 1 compared to group 2 has been observed P=0.001.
This preliminary study has demonstrated the considerable interest of medical simulation as an innovative teaching tool in training on cardiovascular emergencies in pregnant women and its added value compared to “traditional” training programs.
The Aït Attab syncline, located in the Central High Atlas, displays a curved geometry in plan view, and is considered as one of the most spectacular fold shapes in the Central High Atlasic belt. We ...conducted a paleomagnetic study in Jurassic-Cretaceous red beds to investigate the origin of this geometry. The Natural Remanent Magnetization (NRM) is dominated by a secondary magnetization carried by haematite with unvarying normal polarity that has been dated at about 100 Ma. The regional fold test performed in both limbs of the syncline is positive and the paleomagnetic vectors (after tectonic correction) are parallel throughout the curvature, indicating a negative oroclinal bending test. These results are inconsistent with previous works that consider the bent geometry of this syncline to result from subsequent distortion of originally NE–SW trending structures by rotation about a vertical axis. We interpret the NRM data to demonstrate that the changing trend of the Aït Attab syncline is a primary feature, resulting from the influence of pre-existing, NE–SW and E-W-striking extensional faults that developed during a strike-slip regime. Paleomagnetic results also reveal that the tilting observed in the sampled red beds is post Albian, probably linked to the Cenozoic inversion of the High Atlasic belt.
Display omitted
•Application of paleomagnetism to investigate basin evolution.•NRM of Jurassic-Cretaceous red beds is dominated by a Cretaceous remagnetization.•The remagnetization dated at 100 Ma pre-dates major folding in this area.•Two stages of folding are revealed from paleomagnetism and structural analysis.•Oroclinal bending vs. primary curvature of regional syncline is discriminated.
•Magnetic fabrics of 42% of the sampled sites have primary extensional fabric.•Secondary magnetic fabric occurs in sites with axes switching or axes tilted with respect to bedding.•The main carrier ...is hematite and to a minor extent, phyllosilicates.•Post-sedimentary hematite hexagonal platelets carry the secondary magnetic fabric.
New magnetic fabric data from 48 sites in Upper Triassic red beds from the Argana, Asni and Tizi n’Tichka areas in the western High Atlas, in combination with rock magnetic analyses, SEM observations and qualitative chemical analyses, reveal that mineralization processes can affect the primary (extensional) or secondary (post-depositional) magnetic fabrics. Twenty out of the 48 analyzed sites show tectonic-related fabrics consistent with the rifting stage (primary). Their orientation suggests that the extensional Atlasic (for the Asni area) and Atlantic (for Argana area) distinct directions prevailing during Liassic times are already present in the Upper Triassic sediments. The other 28 sites show axes switching (including different possibilities, kmax-kmin or kint-kmin), indicating their secondary development related to mineralogical changes after deposition. However, orientation of magnetic susceptibility axes (without considering their relative value) is consistent with the main directions obtained for the rifting stage. This magnetic fabric study also suggests that (i) extension had a small transtensional component and (ii) there is a limited influence of compressional inversion tectonics.
•We investigate the magnetic fabric in two inverted sedimentary basins from the Moroccan High Atlas.•We use ASM as a tool to study the paleo-stress field in terrigenous basins considering the lack of ...syn-sedimentary faults.•Lack of meso-structures makes difficult the interpretation of magnetic lineation.•In this work we try to interpret the AMS results according to the previous structural works in the Atlas belt.•Magnetic lineation reveals the stability of stress field since Bathonian to Albo-Cenomanian times in the both basins.
The aim of this work is to study the Anisotropy of the Magnetic Susceptibility (AMS) in two Jurassic–Cretaceous synclines located in the northern border of the Central High Atlas (Morocco): the Aït Attab and Ouaouizaght basins. AMS is used in order to obtain the magnetic fabric and its relationship with the kinematic evolution of both basins. The tectonic evolution of the basins, still under discussion, is mostly considered as the result of inversion during Tertiary and perhaps since Bathonian, of extensional and/or strike-slip Jurassic basins. Both basins are filled with Upper Jurassic to Lower Cretaceous silts and sandstones, with less frequent marine marly limestones.
The bulk magnetic susceptibility (km) generally shows higher values in the red facies (163.2 E−6 in AT and 168.6 E−6 in WZ) than in the yellowish marly limestones (97.88 E−6 in AT and 132 E−6 in WZ). Most sites show an oblate magnetic fabric. The rock magnetic analyses indicate that the main carrier of the magnetic susceptibility for the red facies is hematite, whereas in the yellowish facies there is a dominance of paramagnetic minerals. In both basins, the magnetic lineation (long axis of the ellipsoid, kmax axes) shows a predominant E–W direction. The overlapping of the stress fields during the Atlasic basins evolution, in both compressional and extensional regimes and hinder the straightforward interpretation of the magnetic fabrics. However, a coeval N–S compression during the times of sedimentation with an E–W transtension can explain the magnetic lineation found in many of the sites analyzed in the present work. There are also other less frequent directions of kmax axes (NE–SW and NW–SE) are interpreted as the result of local change of the stress field during the early extensional stage of basin formation.
New Nine-Level SPUC Inverter Using Single DC Source el Gadari, A.; el Ouardi, H.; Alibou, S. ...
IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society,
2019-Oct., Letnik:
1
Conference Proceeding
A new nine level inverter is presented in this paper. It combines PUC and NPC topologies to create a new competitive converter that makes use of small count of power devices to generate more voltage ...levels. A PWM technique is designed to insure the self balancing of capacitors voltages. Moreover, no filters or regulation loop is required which permits a low inverter and installation cost. Authors make use of Matlab Simulink environment to perform the simulation of the proposed concept. Dynamics of the latter was verified against load and DC source voltage change.
Photovoltaic System Based On The PUC9 Inverter El Gadari, A.; El Ouardi, H.; Alibou, S. ...
2019 IEEE 28th International Symposium on Industrial Electronics (ISIE),
2019-June
Conference Proceeding
A new competitive photovoltaic system based on the PUC9 converter is presented in this paper. It uses a reduced count of semiconductors and passive components. These advantages are performed using a ...control technique which allows the balancing of capacitors voltages in open loop operation. The proposed system allows a power conversion with high energetic efficiency which is due to the reduced harmonics impact of the PUC9 inverter. The Perturb & Observe algorithm is performed to extract the maximum power of the PV panel. The whole photovoltaic system is based on the association of this MPPT technique and the proposed balancing technique. Consequently, the load voltage and current are nearly sinusoidal. Therefore, there is no need for additional investment in any filters.
Discussion about the age and the structural framework of the Neogene sedimentation within the "zone des dômes" in northern Tunisia. The sedimentation of the Neogene post-Tortonian in the dome zone of ...Northern Tunisia was carried in two kinds of basins corresponding to subsident syncline gutters born of the Tortonian folding and pull-apart basins associated to the dextral subequatorial strike-slips. The Neogene sediments contain a rearranged fauna of Cretaceous, Paleogene and Lower Miocene stages. This phenomenon indicates its post-tectonic character. The Neogene series are framed by two major unconformities which indicate its sedimentation in a compressif structural setting, characterizing the Northern Tunisian Atlas.
La sédimentation du Néogène post-Tortonien moyen dans la zone des dômes, en Tunisie septentrionale, s'est effectuée dans deux types de bassins, correspondant soit à des gouttières synclinales subsidentes, issues des plissements tortoniens, soit à des fossés de type pull-apart développés sur des décrochements dextres subéquatoriaux. Les sédiments néogènes renferment de la faune crétacée, paléogène et même du Miocène inférieur, remaniée. Ceci permet de souligner leur caractère post-tectonique miocène. Ils sont encadrés par deux discordances majeures qui reflètent leur sédimentation dans un cadre structural compressif, caractéristique de l'Atlas tunisien septentrional.
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