Study of Regional Tectonics Related to the Natural Tamda Lake Creation (Northern Middle Atlas of Morocco)

The north of Morocco is affected by frequent landslides representing a significant risk. Understanding the mechanisms behind this event is essential for the risk reduction process. This study focuses on Tamda natural lake and a series of small lakes in the Northern Middle Atlas, where few studies have been conducted. We aimed to investigate the regional tectonics and the ground instability that has played an indispensable role in forming those lakes. From a structural point of view, this site is located between the Southern and Northern Middle Atlas Accidents (SMAA and NMAA). This area, generally of a carbonate nature (Liasic limestone and dolomite), is characterized by intense fracturing, abrupt topography, extreme climatic conditions, and a very ramified hydrographic system. These factors have influenced the regional instability marked by various types of landslides in the region during the recent quaternary period. The most phenomenal of these landslides gave origin to Tamda Lake located in the Tamtroucht syncline south of the Maghraoua commune. After several field missions, we identified three types of landslides based on morphological criteria: (i) rotational slides, which were the largest in terms of area and with the most pronounced scarps, (ii) translational landslides characterized by a larger failure surface and a single escarpment, and (iii) rockfalls and debris, the latter, and the most frequent form of landslide in the region, characterized by the fall of large rocks carrying with them rubble forming an avalanche of debris. The morphotectonic studies of these different types of sliding allow concluding that the tectonic activity on recent quaternary related to the major faults of the region is the origin of these events.