Mineralogy and Geochemistry of the Guenfouda Clay Deposit, Jerada Province, Northeastern Morocco

peer reviewedThe Guenfouda clay deposit is located at about 36km to the southwest of Oujda city and 6km to the south of Guenfouda village. It belongs to the Jerada Province of the northeastern Morocco and hosted within the Upper Visean calc-alkaline dacite lava interbedded within a schisto-volcanic complex. This deposit is mined for more than 15 years and the product being mainly used for refractories and industrial ceramics. This clay deposit is funnel or trough-like in form, narrowing downwards and display a E–W trend, which follows the major dextral strike-slip fault that passes through the south of the deposit. Based on mineral assemblages, four lateral alteration zones were defined from the north to south parts of the deposit: the Illite zone, the Pyrophyllite-illite zone, the Pyrophyllite zone and the Quartz zone. The presence of high-temperature minerals such as pyrophyllite, diaspore, the alteration zonation pattern and the chemical characteristics are diagnostic of hypogene origin. However, the variation diagrams, Zr vs TiO2 and P2O5 vs SO3 as well as the values of the chemical Index of Weathering (CIW) and the Alteration Index (AI) revealed a mixed type. It seems that the genesis of Guenfouda clay deposit was first controlled by the eastwest strike-slip faults, which brought ascending hydrothermal solutions that led to clay formation and finally, the weathering processes have continued and extended the argillization

The application of proximal visible and near-infrared spectroscopy to estimate soil organic matter on the Triffa Plain of Morocco

Soil organic matter (SOM) is a fundamental soil constituent. The estimation of this parameter in the laboratory using the classical method is complex time-consuming and requires the use of chemical reagents. The objectives of this study were to assess the accuracy of two laboratory measurement setups of the VIS-NIR spectroscopy in estimating SOM content and determine the important spectral bands in the SOM estimation model. A total of 115 soil samples were collected from the non-root zone (0-20 cm) of soil in the study area of the Triffa Plain and then analysed for SOM in the laboratory by the Walkley-Black method. The reflectance spectra of soil samples were measured by two protocols, Contact Probe (CP) and Pistol Grip (PG)) of the ASD spectroradiometer (350-2500 nm) in the laboratory. Partial least squares regression (PLSR) was used to develop the prediction models. The results of coefficient of determination (R-2) and the root mean square error (RMSE) showed that the pistol grip offers reasonable accuracy with an R-2 = 0.93 and RMSE = 0.13 compared to the contact probe protocol with an R-2 = 0.85 and RMSE = 0.19. The near-Infrared range were more accurate than those in the visible range for predicting SOM using the both setups (CP and PG). The significant wavelengths contributing to the prediction of SOM for (PG) setup were at: 424, 597, 1432, 1484, 1830,1920, 2200, 2357 and 2430 nm, while were at 433, 587, 1380, 1431, 1929, 2200 and 2345 nm for (CP) setup

Mineralogical and physicochemical characterization of the Jbel Rhassoul clay deposit (Moulouya Plain, Morocco)

This study aims at the mineralogical and physicochemical characterization of clays of the Missour region (Boulemane Province, Morocco). For this, three samples were collected in the Ghassoul deposit. The analyses were carried by X-ray diffraction (XRD), X-ray fluorescence (XRF) and Scanning Electron Microscopy (SEM). The thermal analysis from 500 to1100°C was also performed on studied samples, and the fired samples were characterized by XRD and SEM. The XRD results revealed that raw Ghassoul clay consists mainly of Mg-rich trioctahedral smectite, stevensite-type clay, which represents from 89% to 95% of the clay fraction, with a small amount of illite and kaolinite. The associated minerals are variable amount of quartz, dolomite, hematite, gypsum and K-feldspars. The chemical analysis confirms the presence of Mgrich smectite (stevensite) with largest amount in sample containing the highest MgO. The SEM micrographs revealed the presence of automorphous structures with petalslike shape typical of smectite. The Thermal transformations determined by X-ray diffraction indicated that stevensite was transformed to enstatite from 800ºC. Diopside starts to appear from 700°C, which is confirmed by SEM observations, and the quartz is transformed to cristobalite when the temperature exceeds 1100°C

Golunda aouraghei, sp. nov., the last representative of the genus Golunda in Africa

In this paper, we report a new species of the murid genus Golunda at the Plio-Pleistocene site of Guefaït-4 (Jerada, Morocco). It is a large-sized murid characterized by the presence of relative good lateral connections between the tubercles. The new species shows affinities with Golunda jaegeri from Oued Athmenia 1. However, some morphological differences become remarkable when compared. We propose the anagenetic lineage Golunda jaegeri ? Golunda aouraghei, marked by a slight increase of the width and the stephanodonty along the Pliocene-Pleistocene transition. Hitherto, Golunda aouraghei represents the youngest Golunda species recorded in Africa. Report of this murid from Guefaït-4 has significant implications for the biochronological scale of North Africa.Fil: Piñero García, Pedro. Universitat Rovira i Virgili. Institut Català de Paleoecologia Humana i Evolució Social; España. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección de Mastozoología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Agustí, Jordi. Universitat Rovira i Virgili. Institut Català de Paleoecologia Humana i Evolució Social; España. Institució Catalana de Recerca i Estudis Avancats; EspañaFil: Haddoumi, Hamid. Universite Mohammed V. Rabat; Otros paises de ÁfricaFil: El Hammouti, Kamal. Universite Mohammed V. Rabat; Otros paises de ÁfricaFil: Chacón, M. Gema. Universitat Rovira i Virgili. Institut Català de Paleoecologia Humana i Evolució Social; España. Sorbonne University; FranciaFil: Sala Ramos, Robert. Universitat Rovira i Virgili. Institut Català de Paleoecologia Humana i Evolució Social; Españ

Le Paléolithique supérieur de la grotte d’El Harhoura 2, région de Rabat-Témara. Contexte stratigraphique, paléoenvironnemental, archéologique et datations de l’individu H3

International audienceL’obtention de trois dates AMS sur collagène humain de l’individu H3 découvert en 1996 dans la couche 2 d’El Harhoura 2 est l’occasion de faire le bilan sur nos connaissances de cette phase d’occupation.À partir des données des fouilles anciennes et récentes, le contexte stratigraphique et culturel de l’individu H3 est discuté. L’âge estimé, d’environ 12 ka, permet de replacer cet individu dans le contexte chronologique plus large du Paléolithique supérieur de la région de Témara et du Maroc

Amphibians and squamate reptiles from the late Miocene (Vallesian) of eastern Morocco (Guefaït-1, Jerada Province)

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Datation par ESR-U/th combinées de dents fossiles des grottes d’El Mnasra et d’El Harhoura 2, région de Rabat-Temara. Implications chronologiques sur le peuplement du Maroc atlantique au Pléistocène supérieur et son

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Datation par ESR-U/th combinées de dents fossiles des grottes d’El Mnasra et d’El Harhoura 2, région de Rabat-Temara. Implications chronologiques sur le peuplement du Maroc atlantique au Pléistocène supérieur et son environnement

La région de Témara, près de Rabat, abrite plusieurs sites archéologiques et paléontologiques d’une importance majeure pour la Préhistoire du Maroc et du nord de l’Afrique. Les découvertes de restes humains paléolithiques associés à des industries atériennes et du Paléolithique supérieur à Dar es Soltane 2, El Harhoura 1 et aux Contrebandiers, dans les années 1970, ont renforcé l’intérêt des sites de la région de Témara. Deux grottes ont fait l’objet de nombreuses recherches et sont en cours de fouilles : El Mnasra depuis 1990 et El Harhoura 2 depuis 2001. L’application de la méthode de datation ESR-U/Th sur l’émail dentaire permet de fournir des points de repères géochronologiques et de discuter du cadre paléoenvironnemental dans lequel vivait l’Homme paléolithique au Maroc. Les datations ont été réalisées sur des dents fossiles de bovidés prélevées dans des couches attribuées au Paléolithique moyen (Atérien). Pour la grotte d’El Harhoura 2, les âges proposés s’échelonnent entre 92 et 44 ka, et pour la grotte d’El Mnasra, les résultats suggèrent une occupation comprise entre 66 et 89 ka pour les couches 6 et 7. Ces résultats suggèrent que les grottes de la région de Témara ont commencé à être fréquentées par l’Homme moderne dès le stade isotopique marin 5, et ce jusqu’à environ 40 ka.L’enregistrement sédimentaire s’est poursuivi ultérieurement, comme en témoignent les vestiges d’occupations au Paléolithique supérieur et au Néolithique retrouvés en stratigraphie.The region of Temara-Rabat yields several archaeological and palaeontological sites of an utmost importance for the prehistory of Morocco and more generally for Northern Africa. During the seventies, the discovery of Palaeolithic human remains associated with Aterian and Upper Palaeolithic artefacts, at Dar es Soltane, El Harhoura 1 and Contrebandiers, have emphasized the interest of the sites in this area. Two caves have been well-studied and are still under excavation: El Mnasra since 1990 and El Harhoura 2 since 2001. The combined ESR-U/Th method applied to fossil herbivorous teeth allows a chronostratigraphical view thanks to guide marks precising the palaeoenvironmental frame in which humans lived during the Palaeolithic period in Morocco. All dated layers are attributed to the Aterian culture. The analyses were performed on bovid fossil teeth unearthed from layers 8, 5 and 4a at El Harhoura 2, and from layers 7, 6a and 6 at El Mnasra. The preliminary results range between 92 and 44 ka for El Haroura2, and between 89 and 62 ka for El Mnasra. These results suggest that caves of Témara region began to be frequented by modern humans from marine isotope stage 5 until 40 ka. The sedimentary record continued later, as evidenced by remains of occupations during Upper Paleolithic and Neolithic found in stratigraphy