Study of Monogenic Volcanism in a Karstic System: Case of the Maar of Lechmine n’Aït el Haj (Middle Atlas, Morocco)

The Lechmine n’Aït el Haj maar (LNH) is a mixed phreatomagmatic-strombolian vent located in the Causse of the Middle Atlas. The application of tephrostratigraphic, and geophysical studies to the volcaniclastic deposits allowed interpreting the volcanic dynamics of this volcano set up during the Quaternary. Pyroclastic deposits allow us to understand the chronology of the eruptions. These are organized in four eruptive phases. The basal sequences are phreatomagmatic, followed by a strombolian unit. The last activity of LNH is phreatomagmatic. The structural analysis revealed a localized distension signed by fracture geometry, the mixed nature of the volcanism, tectonic markers, and the mechanisms of syn-eruptive tectonics. This subsidence, controlled by the NW-SE to WNW-ESE directions tends towards a strike-slip regime fault NE–SW during the phreatomagmatic-strombolian transition. The latter is favored by the position of the LNH volcano on the path of faults of cryptokarstic origin. The LNH maar is one of numerous well preserved monogenic volcanoes of the Causse of the Middle Atlas. The appropriation of this geoheritage is very important for tourism and territorial development of the region

Environmental management of coastal careers along the Doukkala-Abda linea

This study proposes an environmental management model for sand and gravel quarries along the coastline from Doukkala to Abda. It aims at the one hand; the creation of a regional database bringing together all the quarries to identify and characterize the materials exploited as well as the major impacts and risks associated with subsequent physiographic changes; and on the other hand to develop intervention mechanisms to prevent, reduce or even eliminate the harmful effects of abusive exploitation on the environment and public safety, while taking into account the specificities of the region

Ba- and Ti-rich oxymica from nephelinites in the Middle Atlas Volcanic Province, northern Morocco

International audienceA Ba- and Ti-rich mica (up to 14.0 wt% BaO and 13.1 wt% TiO2) occurs in nephelinites from the Middle Atlas Volcanic Province, Morocco. The rocks show a porphyritic texture composed of olivine, Ti-rich augite, nepheline and Ti-rich magnetite. Oxyphlogopite is found in secondary assemblages consisting of zeolites, clinopyroxene and Ti-oxides. This mineral occurs mostly as euhedral to subhedral crystals lining the walls of zeolitic veinlets and cavities in the nephelinites. The coupled substitutions of (1) Ba for K in the interlayer site and Si for Al in the tetrahedral site and (2) Ti4+ for Mg in the octahedral site and O2- in the (OH, F) site are major mechanisms of Ba and Ti incorporation in these micas. The average structural formula, calculated on the basis of 12 (O, OH, F, Cl), is (Si2.515-Al1.482-Fe3+0.003)4.000 (Al0.050-Ti0.661-Fe2+0.798-Mn0.012-Mg1.500)3.021 (Ca0.014-Ba0.398-Na0.066-K0.502)0.980 O10 (F0.308-Cl0.009-O1.319-OH0.365)2.001, suggesting a combination of oxyphlogopite and oxykinoshitalite, with contribution from the hypothetical end-member "Ti-eastonite". Ba- and Ti-rich oxymica in the nephelinites may have crystallized under the influence of Ba-rich fluids derived from nephelinitic melts during late magmatic stages. The Ba enrichment in the host nephelinites indicates a lithospheric mantle source enriched by the circulation of metasomatic fluids

Heavy metal contamination in surface water of Mohammedia wetland, Morocco

Assessing heavy metal concentrations in wetlands and identifying sources of metal contamination are critical steps in protecting wetlands. Using seven sampling stations, we evaluated the spatial variation of some heavy metal concentrations in surface waters of the Mohammedia wetland and a selected segment of the El Maleh wadi that feeds the wetland. Field observations made it possible to identify and map the pollution discharged into El Maleh wadi, carrying heavy metals into the wetland. The analyses showed that the concentrations of lead, manganese, and cadmium far exceed the thresholds relating to fish life in 100% of sampling stations. All the evidence points to heavy metals contamination of surface water in Mohammedia wetland, generated by industrial activities, wastewater discharges, and leachate from the old landfill located upstream

Influence of the clay composition on the quality of traditional ceramics: example of the site of Mzouda (Central Morocco)

peer reviewe

Geomorphological Classification and Landforms Inventory of the Middle-Atlas Volcanic Province (Morocco): Scientific Value and Educational Potential

Through the tabular morphology of northwestern part of the Middle-Atlas in Morocco, numerous uncovered monogenetic volcanoes arise structured of pyroclastic product layers and lava flows. Our fieldwork results witness a wide-ranging volcanic shape spectrum, as cones, maars, tuff-rings, and cone-maar mixes, generally associated with a later lava flow discharge that could develop many surfaces and appearances. There are withal sundry eruptive products such as pahoehoe lava, scoria, tuff, lapilli, peperites, base-surges, bombs, etc. This monogenetic volcanic field of practically 1000 km2 offers remarkable eruptive landforms, referred to as the largest, and the youngest volcanic field in Morocco, which consists of a large area within the Ifrane National Park. This fieldwork study provides a renewed volcanic geomorphological classification table and GIS data to be used by a wide public range for both educational and geo-touristic interest and access effectively to such a high-mountain natural museum. In the event that these volcanic structures were appropriately dealt with, the high educational scientific content and the notable touristic vocation would almost certainly create business openings and new financial wages for neighborhood populaces. This work focuses to share our outcomes and emphases the scientific value about the monogenetic volcanic field around the tabular Middle-Atlas in Morocco

Geomorphological classification and landforms inventory of the middle-atlas volcanic province (morocco): scientific value and educational potential

Through the tabular morphology of northwestern part of the Middle-Atlas in Morocco, numerous uncovered monogenetic volcanoes arise structured of pyroclastic product layers and lava flows. Our fieldwork results witness a wide-ranging volcanic shape spectrum, as cones, maars, tuff-rings, and cone-maar mixes, generally associated with a later lava flow discharge that could develop many surfaces and appearances. There are withal sundry eruptive products such as pahoehoe lava, scoria, tuff, lapilli, peperites, base-surges, bombs, etc. This monogenetic volcanic field of practically 1000 km2 offers remarkable eruptive landforms, referred to as the largest, and the youngest volcanic field in Morocco, which consists of a large area within the Ifrane National Park. This fieldwork study provides a renewed volcanic geomorphological classification table and GIS data to be used by a wide public range for both educational and geo-touristic interest and access effectively to such a high-mountain natural museum. In the event that these volcanic structures were appropriately dealt with, the high educational scientific content and the notable touristic vocation would almost certainly create business openings and new financial wages for neighborhood populaces. This work focuses to share our outcomes and emphases the scientific value about the monogenetic volcanic field around the tabular Middle-Atlas in Morocco