Présenté par Jean DercourtRésumé -L'analyse de la fracturation dans les bassins permiens des Jebilet, des Réhamna (Maroc hercynien) et les terrains sous-jacents permet de proposer un modèle pour leur ouverture. Trois épisodes tectoniques sont distingués : un épisode transtensif NNE-SSW (Permien I), responsable de l'ouverture des bassins le long des accidents décrochants sénestres N070-110 associés à des failles normales N05-40 synsédimentaires ; un épisode transpressif ESE-WNW (Permien II), qui amorce la fermeture, les failles normales rejouant en inverses dextres, les accidents N070 en dextres ; enfin, un épisode compressif NNW-SSE (post-Permien-anté-Trias), qui accentue la fermeture ainsi que les déformations des bassins et met fin aux mouvements compressifs tardi-hercyniens.
Drainage network patterns influence the hydrological response of the watersheds and must be taken into account in the management of the water resource. In this context, it is important to identify the factors that control the configuration of drainage networks in and beyond specific climatic conditions. Here, we study 318 basins spread over three sectors (arid, semi-arid, and semi-humid) of Morocco where seven drainage network patterns have been identified. From each basin, 14 parameters were extracted, describing the relief, geology, morphometry, drainage network, land cover, precipitation, and time of concentration (Tc). Principal component analysis (PCA) and discriminant analysis (DA) processing were performed on the entire database and on each sector separately. The results show that the drainage network pattern is a feature of the landscape that contributes significantly to the variance of the basins. They suggest that the distribution of network patterns is controlled by the relationship between the different parameters, mainly those related to the relief, more than by the variations of each parameter taken individually. The network discrimination rate is 63.8%, which improves when each sector is treated separately. Confusion in discrimination are similar across all sectors and can be explained by similar conditions (active tectonic, deformation, and uplift) or transitions from one network pattern to another, due to the landscape evolution of certain sectors. A contribution of climatic variables appears locally but was attributed to a statistical coincidence, these parameters presenting a distribution close to that of the relief and geology variables.
La série métamorphique d'âge Paléoprotérozoïque de la boutonnière de Zenaga forme l'encaissant de granites éburnéens. Il s'agit d'une série monotone, à structuration générale E-W à NE-SW, formée essentiellement d'amphibolites, de schistes peu métamorphiques et de micaschites à grenat et sillimanite.
L'étude pétrographique et géochimique montre que les amphibolites proviennent d'anciens niveaux volcaniques à composition basaltique et que les schistes et les micaschistes dérivent probablement d'une série turbiditique formée par l'alternance de métashaJes et de m étagrauwackes avec prédominance de ces derniers.
L'analyse structurale a mis en évidence au moins trois phases de déformation : la phase D1 est rattachée à l'orogenèse éburnéenne, alors que la phase D2 qui est hétérogène non coaxiale en régime cisaillant sénestre et la phase D3 de crénulation, correspondent à l'orogenèse pan-africaine.
La première paragenèse métamorphique associée à la schistosité SI est une paragenèse mésozonale du faciès amphibolite. La paragenèse principale associée à S2 traduit une rétromorphose épizonale dans le faciès schiste vert, avec des conditions de pression et de température estimées à P = 2 à 2,5 Kb et T = 450° C.
Abstract. Nassri I, Tahri L, Saidi A, Ameur N, Fekhaoui M. 2021. Prevalence, diversity and antimicrobial resistance of Salmonella enterica and Pseudomonas aeruginosa isolates from spring Water in a rural area of northwestern Morocco. Biodiversitas 22: 1363-1370. The persistence and diversity of serotypes belonging to pathogens in environmental waters including surface and groundwater have been widely documented and that the aquatic environment represents a relatively stable environment for these microorganisms. Study was carried out on the prevalence, diversity, and antibiotic resistance of Salmonella enterica and Pseudomonas aeruginosa isolates taken from 102 samples of spring water in a rural region of Northwestern Morocco (Rabat-Salé-Zemour-Zaer) collected for two seasonal campaigns between March 2010 and June 2011. The search and identification of S. enterica and P. aeruginosa were carried out according to ISO 19250 and ISO 16266 methods respectively. The serotyping of S. enterica and P. aeruginosa was carried out according to the Kauffmann and White and IATS (International Antigenic Typing System) schemes respectively. Antibiotic resistance of S. enterica and P. aeruginosa were carried out by the Mueller-Hinton agar diffusion method (Biorad). S. enterica showed a prevalence of 10.7% with 09 different serotypes circulating including S. paratyphi B, S. brandenburg, S. kentucky, S. group III b (serotype 50: z52: z53,), S. boon, S. tshiongwe, S. assinie, S. togo, and S. tanger. In contrast, P. aeruginosa showed a prevalence of 21.6% with 07 different serotypes circulating including O6, O1, O7, O9, O4, O3, and O10. In this study, antimicrobial resistance revealed that all isolated strains of S. enterica and P. aeruginosa still exhibit a wild resistance phenotype. Contaminated water sources are reservoirs of these pathogens but do not yet present the risk factors for these bacteria to develop antibiotic resistance.
Les terrains du Carbonifère inférieur de la région d'Agouraï s'organisent en trois formations qui passent de dépôts littoraux détritiques à des dépôts carbonatés de plate-forme interne peu profonde puis à des dépôts de décantation de milieu ouvert. Ils sont datés du Viséen moyen (V2a -V3a) au Viséen supérieur (V3ba, probablement V3bP). Le V2a-V3a est particulièrement intéressant et peut servir de modèle pour une échelle marocaine.
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