Volcanic geosites assessment in the Plio-Quaternary Azrou-Timahdite Plateau (Middle Atlas, Morocco)

Abstract

During the Plio-Quaternary, the Azrou-Timahdite Plateau (PAT), considered as “the land of lakes and volcanoes”, was the region of alkaline volcanism associated with the penecontemporaneous NE-SW trending strike-slip fault movements system. This volcanism is the most recent and the most extensive in Morocco. It occupies 7.8% of the Middle Atlas range area where the majority of volcanic edifices follow an NNW-SSE-oriented trend. The volcanic field occupies an area of about 1000 km2. The present study allowed us to inventory 76 volcanic geosites that comprise a range of volcanic structures that are unique in Morocco. 26 are retained during the quantitative assessment. 33% of the sites were filtered for the scientific assessment stage (26 sites out of 76), including 5 of high scientific value and 21 of medium scientific value. Of these 26 sites, 84% show a moderate to a high degree of deterioration (22 of 26). However, only 6 sites have a negative total value, having a deterioration value greater than the scientific value, demonstrating the considerable scientific importance of the sites in the region, which requires more attention and protection. It should be noted that only 3 steps (inventory, quantitative assessment, degree of deterioration) of the adopted methodology were applied. In fact, due to the large number of geosites with a medium to high risk of deterioration, the fourth step (usage value) was excluded. Besides, we have chosen to present the detailed geological, geomorphological, and volcanic specificities of 5 geosites of high scientific value. These geosites hold specific characteristics among the other volcanoes of the PAT: their eruptive dynamism, their size, their shape, their extent, and the nature of their pyroclastic products.