Mustapha Boualoul

Fallas normales y diques clásticos son estructuras comunes que afectan a las calizas lacustres de la cuenca de antepaís Saiss, al norte de Marruecos. Estas estructuras extensionales y de dilatación tienen dos direcciones principales NNW-SSE y NE-SW y están relacionadas con episodios tectónicos recientes cuaternarios en calizas masivas y travertinos. Estas estructuras tensionales se han analizado en diferentes localizaciones de la ciudad de Meknes y áreas cercanas. Las fallas normales tienen geometría lístrica y afectan a areniscas y calizas, determinando en ocasiones estructuras de tipo horst-graben. Los diques clásticos aparecen solamente en las calizas, rellenos de arcillas rojas resultado de la alteración de suelos por la infiltración de agua de lluvia y clastos procedentes de las paredes. Tienen una disposición vertical a subvertical y están asociados a las fallas normales y fracturas. Estos resultados definen la tectónica extensional del Cuaternario tardío y contribuyen a compr...

The Achemmache region is located in the East of El Hammam district, in the Eastern part of the Northern Hercynian Central Morocco; Tin concentrations, economically exploitable, have been recognized in brecciated tourmaline structures of Late Visean, and generally oriented E-W. Therefore, they contrast with other tourmaline oriented NE-SW which proved barren. In order to keep the horizontal and vertical continuity as well as the dip and extension of mineralized structures in the sector, a geophysical survey by Horizontal Electrical resistivity (TE) prospecting and Electrical Tomography was performed in the region. The TE1 profile was performed in the West Zone where the mineralized structures outcrop; it allows highlighting four positive anomalies, while the TE2 profile was carried out in Eastern zone of the sector where the mineralized structures are largely hidden. It can also bring out only two rather distant positive anomalies. These anomalies correspond to mineralized structures...

Le présent travail concerne l'étude hydrogéophysique par intégration de l'outil SIG des rides prérifaines. Ces dernières sont caractérisées par une série sédimentaire jurassique très variée et surmontée en légère discordance angulaire par les dépôts transgressifs du Miocène supérieur. L'étude hydrogéologique sur la base des campagnes piézométriques et de caractérisation physico-chimique a permis de mettre en évidence le sens des écoulements souterrains dans les différents aquifères qui présentent en général une bonne qualité des eaux, ainsi qu'une fracturation et perméabilité importante qui permet d'avoir des débits allant jusqu'au 40l/s. Les résultats des campagnes géophysiques par prospection sismique réalisée dans les rides prérifaines et plus précisément celles réalisées sur le secteur d'étude couvrant le synclinal de Ain Kerma et les rides ont permis l'élaboration de plusieurs cartes interprétatives qui ont permis de suivre les horizons aquifères...

Vertical electrical sounding (VES) as a geoelectrical method has proven its effectiveness throughout the history of groundwater geophysical investigation. In this sense, VES was carried out 47 in the study area with the aim of determining the geometry and limits of Quaternary basaltic aquifer formations and, above all, the location of electrical discontinuities in the area located in the north of Morocco, between the center of Almis Guigou and the city of Timahdite. This area is experiencing an overexploitation of the groundwater due to excessive pumping and the development of intensive agriculture activities, resulting in a continuous decrease in piezometric levels. The processing of the diagrams by WINSEV software showed the presence of an electrically resistant surface level, attributed to basaltic formations, of the Quaternary age, whose thicknesses reach at least 150 m to the SW of the area. This level is superimposed on a moderately conductive horizon which, according to local...

Numerical analysis of geophysical data to uncover Precambrian belts and probably to enclose mineral deposits is becoming once more communal in mining activity. The method is founded on typifying zones branded to comprehend deposits and looking for analogous areas. The proposed work outlines a semi-automatic image processing system for the structural and mining investigation of the Bou Azzer inlier, which varies from preceding approaches as it is centered only on aeromagnetic data. The aeromagnetic signature of what seem to be geologically expressive features are pursued within the aeromagnetic items. Cobalt and associated mineralizations in the Bou Azzer inlier are recognized to arise nearby main crustal discontinuities revealing as significant shear zones, which turn act as drains for mineralizing fluids. Mineralization occurs in sectors of structural complexity beside the shear zones. Developing towards the semi-automatic uncovering of such regions, the furthermost prospective ext...

An electrical survey was carried out in the TSELFAT zone (SIDI KACEM - MOROCCO). The objective of the prospection was to trace the top of sandy limestone and limestone formations from the Miocene age. These materials could be used as raw material for cement manufacture if they were present in sufficient quantities. The results of the geophysical soundings show the succession of layers with resistivity ranging from 50 to 1300 Ω.m and thickness from 0.5 to 80 m. Considering the geological context, the sandy limestone and limestone layers at the study site are very interesting because they can establish a reserve of raw material.

Dans le sud du massif central francais, les terrains metamorphiques du rouerque cristallin comprennent plusieurs associations de metagranites, d'orthogneiss illes, de gneiss micaces et de micaschistes, interpretees classiquement, comme derivant soit de granites intrusifs dans un encaissant pelitique, soit de series volcano-detritiques. Une nouvelle interpretation est proposee pour quatre d'entre elles: le massif orthogneissique du pinet et son encaissant micaschisteux et les associations de gneiss illes, de gneiss micaces et de micasschistes des formations de viviez, de villefranche-de-rouergue et d'escandolieres. Dans cette interpretation, la deformation ductile symmetamorphe de granitoides, associee a des transferts de matiere, conduit progressivement a des orthogneiss illes, puis a des facies d'apparence banale (gneiss micaces et orthomicaschistes). Ces divers facies lithologiques presentent entre eux des passages plus ou moins progressifs et localises dans des zones de cisaillement ductile metriques a hectometriques. Cette transformation, de type blastomylonitique, est caracterisee par d'importants changements mineralogiques accompagnant l'acquisition d'une foliation. Du point de vue chimique, elle se traduit par des pertes et grains en certains elements chimiques, conduisant a des pertes en volume. Ces transferts de matiere montrent le role important joue par la phase fluide lors de la deformation. Une telle interpretation, pourrait s'appliquer a d'autres ensembles metamorphiques et conduire a reevaluer l'importance du materiel d'origine granitique dans divers orogenes

Direct current Resistivity (DCR) method was carried out to characterize the hydrogeological connection between the Tabular Middle Atlas (TMA) and the Saïs Basin. The TMA is one of the most important aquifers in northern Morocco that supplies the deep aquifer of the Saïs Basin. Electrical resistivity tomography (ERT) survey was focused on the Bittit area that is one of the most important outlet discharges, and it is representative of the relations between the TMA and the Saïs Basin. The high resolution capabilities of the electrical tomography were used to define the geological draining features in the framework of water paths from the TMA to the karstic springs. The synthetic data were calculated for the similar model expected in field data inversion and inversion result of these synthetic data used as a guide for the interpretation of the inverse data resistivity sections. Joint interpretation of geophysical, geological, structural, and synthetic simulation data allowed identifying...

The Tabular Middle Atlas reservoir is one of the most important aquifers in northern Morocco. It is mainly a water table fractured reservoir consisting of Lias limestone and dolomite. The matrix permeability is very low and water flows essentially along open fractures and karsts. The Bittit Spring belongs to this karstic system and constitutes an important aquifer lying at the junction between the tabular reservoir and the Sais basin. Bittit spring, with an average annual discharge of about 1600 l/s, contributes largely to water supply of the big city of Meknes. Groundwater circulation is complex due to tectonics and to presence of karstic Quaternary travertine overlying Lias carbonate. In Bittit area, travertine is mostly covered by Quaternary basalt. Up to now water flow paths and the underground karst organization remain misknown, and turbidity affects the water quality after rain events. To highlight these issues, an integrated geophysical survey was performed in this area in th...

The Kelaat Mgouna lower Neoproterozoic group consisits of five siliciclastic formations. It has been considered to have been deposited in a back-arc basin related to a subduction zone corresponding to the 'accident majeur de l‘Anti-Atlas’. In this model, the detrital material would have evolved from a volcanic arc.In fact, the modal composition of the greywackes and conglomerates and the analysis

This study analyzes the fracture network at different scales in the Lower Jurassic limestones outcropping in the Agourai plateau, Middle Atlas, and their relationship with karst structures. This zone belongs to the Sub-Tabular Middle Atlas belt, called "Causses Moyen-Atlasiques ". This area underwent a polyphased tectonic evolution, involving karst depressions aligned NE-SWparallel to the main faults. The approach is based on the fracturing analysis and the determination of relationships between tectonic events and the main karstic structures development, corresponding to aligned dolines forming important uvala systems. We analyze the karst distribution along the main faults affecting Liassic carbonates and we describe some karst sedimentary fillEste trabajo muestra un análisis de la fracturación a diferentes escalas que afecta a las calizas del Jurásico Inferior del plateau de Agourai, Atlas Medio Esta zona pertenece al cinturón subhorizontal medio del Atlas y ha sufrido ...

Deep water bodies constitute the strategic water reserves of Morocco. These natural resources are used in many activities such as irrigation in agriculture, and, more importantly, they are the source of fresh drinking water for the local population. However, these resources are vulnerable to anthropogenic and natural phenomena due to ongoing climate change and the increase in population growth. To contribute to the recent initiative for the protection of the karstic environment of water springs in the Tabular Middle Atlas of El Hajeb, the present research work aims to characterize different karst landforms in Liassic carbonate rocks of the Tabular Middle Atlas in the Causse of El Hajeb, where pollution identified in water samples in this region originates. Satellite imagery (Sentinel-2, Landsat, Terra-ASTER, ASTER-GDEM) and GIS tools were used. Based on surface reflectance of dolomite and limestone, especially in shortwave infrared, we delineated the extent of carbonate rocks and areas with intense human activities. Fractures affecting these Liassic rocks were extracted mechanically and manually after the application of Sobel operator filter in N, S, NE and SW main directions. The results show an improvement and a better understanding of the hydrogeological system of this karst environment, in particular the location of new faults identified in NESW and NW-SE fault systems which involve infiltration of surface water and groundwater drainage respectively. The percolation of slightly acidic water through these fractures has gradually created cavities and sinkholes which are believed to be the origin of turbidity observed during the analysis of the water springs.

The renowned Causse d'El Hajeb study area is located in northern Morocco; it is bounded to the north by the Saiss basin, to the south by means of the pleated atlas, to the west by the Causse of Agouray and the East by the Bsabis's Causse. The results obtained from these profiles have revealed at the anomalies corresponding to faults and / or fractures, which serve the flow of groundwater at the Causse to the plain of Saiss, using the electromagnetic VLF Low Frequency). This study consisted of four (04) profiles in the N-S directions for the VLF1 profil and E-O for the VLF 2, VLF 3 and VLF4 profiles, with a length distance of 300 to 470m with 10m steps.

The mapping of hydrothermal alteration zones associated with mineralization is of paramount importance in searching for metal deposits. For this purpose, targeting alteration zones by analyzing airborne geophysical and satellite imagery provides accurate and reliable results. In the Kelâat M’Gouna inlier, located in the Saghro Massif of the Moroccan Anti Atlas, natural gamma-ray spectrometry and ASTER satellite data were used to map hydrothermal alteration zones. Natural gamma-ray spectrometry data were processed to produce maps of Potassium (K in %), Uranium (eU in ppm), Thorium (eTh in ppm) and ratios of K/eTh and K/eU. In addition, four-band ratios were computed, on ASTER data, to map the distribution of clay minerals, phyllitic minerals, propylitic minerals, and iron oxides. The combined results obtained from geophysical and satellite data were further exploited by fuzzy logic modelling using the Geographic Information System (GIS) to generate a mineral prospectivity map. Seven ...

espanolEste trabajo muestra un analisis de la fracturacion a diferentes escalas que afecta a las calizas del Jurasico Inferior del plateau de Agourai, Atlas Medio Esta zona pertenece al cinturon su bhorizontal medio del Atlas y ha sufrido una evolucion tectonica polifasica, con depresiones karsticas alineadas NE-SO paralelas a las fallas principales. Este estudio esta basado en el analisis de la fracturacion y la determinacion de relaciones entre los eventos tectonicos y el desarrollo de las principales estructuras karsticas, que corresponden con dolinas alineadas formando sistemas de uvalas. Analizamos la distribucion karstica a lo largo de las fallas principales que a fectan a las calizas del Lias y describimos los rellenos karsticos de algunas de ellas. EnglishThis study analyzes the fracture network at different scales in the Lower Jurassic limestones outcropping in the Agourai plateau, Middle Atlas, and their relationship with karst structures. This zone belongs to the Sub-Tabu...

The renowned Causse d'El Hajeb study area is located in northern Morocco; it is bounded to the north by the Saiss basin, to the south by means of the pleated atlas, to the west by the Causse of Agouray and the East by the Bsabis’s Causse. The results obtained from these profiles have revealed at the anomalies corresponding to faults and / or fractures, which serve the flow of groundwater at the Causse to the plain of Saiss, using the electromagnetic VLF Low Frequency). This study consisted of four (04) profiles in the N-S directions for the VLF1 profil and E-O for the VLF 2, VLF 3 and VLF4 profiles, with a length distance of 300 to 470m with 10m steps.

The Causse of El Hajeb belongs to the Tabular Middle Atlas (TMA), in which thousands of karst landforms have been identified. Among them, collapse dolines and dissolution sinkholes have been highlighted as a source of environmental risks and geo-hazards. In particular, such sinkholes have been linked to the degradation of water quality in water springs located in the junction of the TMA and Saïss basin. Furthermore, the developments of collapse dolines in agricultural and inhabited areas enhance the risk of life loss, injury, and property damage. Here, the lack of research on newly formed cavities has exacerbated the situation. The limited studies using remote sensing or geophysical methods to determine the degree of karstification and vulnerability of this environment fail to provide the spatial extent and depth location of individual karst cavities. In order to contribute to the effort of sinkhole risk reduction in TMA, we employed remote sensing and geophysical surveys to integra...

Tabular Middle Atlas of El Hajeb holds the most important water aquifer which provides water for the people living in the Cities of El Hajeb, Meknes and Fez. This aquifer is located in Liassic dolomite and limestone. These carbonate rocks constitute a karst environment which is facing more problems - such water pollution, water table level fluctuation, sinkholes collapse, surface erosion, increase water turbidity and water spring drying up - due the ongoing climate change and increasing population growth, and hence become more vulnerable environment. In order to identify the level of vulnerability across this region, we used PaPRIKA method, [1] as a tools to estimate the origin of this vulnerability. Adopting a multidisciplinary methodology approach integrating remote sensing, applied geophysics and on-ground-based lithology and structural measurements, we analyzed four criteria (Protection, reservoir, Infiltration and karstification) which involved in the application of PaPRIKA met...