Les microbialites de l’Anti-Atlas occidental : marqueurs stratigraphiques et géodynamiques au Cambrien inférieur

Benssaou Mohamed. Les microbialites de l’Anti-Atlas occidental : marqueurs stratigraphiques et géodynamiques au Cambrien inférieur. In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. p. 40

L'Anti-Atlas occidental du Maroc : remplissage sédimentaire d'un bassin de type rift intracontinental au Cambrien inférieur

The western Anti-Atlas from Morocco : sedimentary deposits in an intracontinental rift basin during the Lower Cambrian. During a lower Paleozoic distensif event, the synrift succession of the Western Anti-Atlas is interpreted as the result of a partly infilled rift basin generated in the Western Anti-Atlas. Reconition of sedimentary environments is based on the stady of various lithofacies. The differential tectonics is the main control on basin structuration and consequently on rift basin architecture. Extensional events were begining at Anzi-Ait Abdallah axis, propagation of this distensional tectonics allow to reach the Northern border of Kerdous. The first event is represented by the Anzi group, wherease the second one is represented by the Asghrkyis group. During the lower Cambrian postrift event, the resulting vertical facies association of the representative succession shows a stack of tow sedimentary groups. The Madaw group reflect an increased eustatic rise and a tectonic steady stage, while the Ait Abdallah group is the result of a tectonic subsidence and eustatic control on basin sedimentation and consequently sequential organisation.Dans l'Anti-Atlas occidental, la caractérisation stratigraphique et sur¬ tout sédimentologique, (identification des faciès et reconstitution des paléo-environnements) des formations attribuées au Cambrien inférieur, permet de mettre en évidence deux phases de remplissage d'un bassin de type rift intracontinental avorté : une phase synrift et une phase post-rift. Chaque phase est représentée par une série sédimentaire. La série qui représente la phase synrift constitue le comblement partiel d'un bassin de type rift continental. Le développement de ce bassin, initié durant l'événement distensif du Paléozoïque inférieur, peut être ramené à deux événements tectoniques essentiels : la première étape d'individualisation, représentée par le groupe d'Anzi, est limitée à l'axe Anzi-Ait Abdallah et la deuxième, représentée par le groupe d'Asghrkyis, est marquée par l'extension de la distension qui atteint le Nord de la boutonnière de Kerdous. Durant la phase postrift, l'étude sédimentologique et lithostratigraphique des formations sédimentaires de la série représentative a permis d'élaborer un découpage lithostratigraphique en séquences composites et en séquences élémentaires. Les deux groupes sédimentaires reconnus dans la région traduisent une phase de stabilité tectonique relative associée à une remontée eustatique de grande ampleur (groupe de Madaw) et une phase, représentée par le groupe d'Ait Abdallah, marquée par le contrôle tectonique et eustatique de la sédimentation et de son organisation séquentielle.Benssaou M., Hamoumi Naïma. L'Anti-Atlas occidental du Maroc : remplissage sédimentaire d'un bassin de type rift intracontinental au Cambrien inférieur. In: Géologie Méditerranéenne. Tome 26, numéro 3-4, 1999. pp. 259-279

Le patrimoine naturel - géologique et oasien - au service du développement géotouristique dans la province de Sidi Ifni et son arrière-pays oasien (Maroc)

Fragile environments, the oases of the Western Anti-Atlas contain not only the wealth of biodiversity within them but also a geodi-versity around ; Indeed, oases appear as a space full of rich phoenicicole heritage and having an important role in the socio-economic development of arid and semi-arid areas. However, these areas are characterized by their hypersensitivity to desertification and any human intervention : extraction, inappropriated touristic development, etc. The aim of this article is to develop a territorial approach with the preservation and the development of the geological and geo-morphological heritage in the oasien context. Focused on the Sidi Ifni Province and its hinterland oasis, this study analyses how to protect the resources to produce wealth, and enhancing the potential land without risking biodiversity and geodiversity of these vulnerable areas ?Milieux fragiles, les oasis de l'Anti-Atlas occidental recèlent des richesses de biodiversité et de géodiversité ; elles sont par ailleurs un espace abritant un patrimoine phoenicicole varié et ayant un rôle socio-économique important dans le développement des zones arides et semi-arides du sud marocain. Mais ces espaces sont aussi caractérisés par une hypersensibilité à la désertification et à toute intervention anthropique : extraction minière, développement touristique inapproprié , etc. Cet article met l'accent sur la mise en place d'une approche territoriale visant à valoriser les ressources géologiques et géomorphologiques des oasis. Ciblée sur la province de Sidi Ifni et son arrière pays oasien, notre démarche repose sur la question suivante : comment protéger les ressources, produire de la richesse et valoriser les potentialités territoriales, sans pour autant porter atteinte à la biodiversité et la géodiversité de ces espaces vulnérables ?Albab Siham, Ezaidi Abdelkrim, Benssaou Mohamed, Kabbachi Belkacem. Le patrimoine naturel - géologique et oasien - au service du développement géotouristique dans la province de Sidi Ifni et son arrière-pays oasien (Maroc). In: Collection EDYTEM. Cahiers de géographie, numéro 14, 2013. Ressources patrimoniales et alternatives touristiques, entre oasis et montagne. pp. 117-130

Rock Art Conservation and Geotourism: A practical example from Foum Chenna engravings site, Morocco

The rock engravings, the subject of this article, are artistic representations made by people from cultural communities who no longer exist. The rock art was a way of expressing their thoughts, culture and beliefs, before the invention of writing. The engravings represent an archive of an ancient civilization which developed over thousands of years throughout North Africa, from the Atlantic to Egypt and from the Atlas Mountains to the Sahel. Morocco has more than 300 listed rock art sites, scattered throughout the country. Foum Chenna is a major site in the Anti-Atlas Mountains of southern Morocco. The engravings were predominantly made by pecking out images of human figures, animals and patterns, and the area today is the center of interest for the recently-formed Association of Rock Art Heritage of Southern Morocco, based in Zagora. Foum Chenna is a place of primary importance with more than 800 schematic engravings made using the pecked technique, a characteristic of this period. The majority of engravings which depict riders associated with zoomorphic and anthropomorphic representations, also, importantly, the numerous rock inscriptions recounting a scriptural tradition and reflecting the historical beginnings of Libyan writing, were today revitalized to transcribe the Tamazight language. The need to study and protect this heritage should not be limited to the preserve of just a few specialists. Knowledge of it can be used, with care, for sustainable human development. The rock art and other featuresmay make the region worthy of international recognition by UNESCO. In this paper, we look at Foum Chenna site from the perspective of geotourism and importance of the site for geoeducation, and the value of Foum Chenna site as geosite. Besides, soils, considered as some of the extraordinary manifestations of the culture of the Foum Chenna, are of huge scientific importance

The Missing Link in the Genesis of the Lower Paleozoic Copper Deposits of the Anti-Atlas (Morocco): The Late Triassic Central Atlantic Magmatic Province Event

Copper mineralization in the Lower Paleozoic sedimentary cover of the Anti-Atlas (Morocco) is continually being revised not only to improve its mining capacity, but also to determine its origin, which remains a matter of debate. As evidenced by the various models proposed, the related research is fragmented, localized, and confusing. The origin of the Anti-Atlas Lower Paleozoic copper mineralization is shared between synergistic and epigenetic processes or a superposition of the two processes. Based on new tectono-magmatic data and a reinterpretation of the ore structural arrangement, we propose a link between the last concentration of copper deposits and the Late Triassic–Early Liassic CAMP (Central Atlantic Magmatic Province) tectono-thermal event, as evidenced by the significant concentration of copper mineralization in the three NE–SW corridors affected by extensional faults, some of which are filled with dolerite CAMP magma. The heat flow generated by the mafic dykes within these reactivated corridors causes mineralized fluids to up well into the sedimentary layers, depositing material rich in juvenile or leached copper, or even a mixture of the two. In some cases, these fluids are trapped by fracture systems that accompany passive folds initiated on normal faults. In other cases, these fluids can infiltrate bedding planes, and even karst caves, formed during carbonate exhumation. Notably, extensive NE–SW faults systematically cover the early Hercynian structures, suggesting that they belong to a post-Hercynian extensional episode. During the Late Triassic, the global fragmentation of the Pangaea supercontinent was manifested by the stretching of the continental crust at the margin of northwest Africa, with the simultaneous opening of the Central Atlantic Ocean and emplacement of CAMP magmatism. This last and often overlooked tectonothermal event must be considered in the remobilization and reconcentration of copper mineralization and other mineralization in Morocco