Morphotectonic Frame of the Mount Cameroon Area, Based on Remote Sensing and GIS Techniques: Preliminary Results

The elaboration of selected satellite images processed with remote sensing and GIS techniques allows us to provide detailed thematic maps for the Mount Cameroon area belonging to the Cameroon volcanic Line. The hillshade, slope and drainage maps were calculated from the SRTM DEM and then used together with the Landsat 7 ETM + and Landsat 8 OLI images to map the tectonic and volcanic structures. The accurate analysis of the thematic layers and Landsat images allows us to manually map the main structures of the study area which is dominated by the Mount Cameroon volcano. Using lithological, morphological, tectonic and volcanic structures, the area can be divided into six morphotectonic zones and 12 sectors, and with respect to the literature, some known tectonic structures can be mapped to further detail, whereas others are not confirmed by our analyses. Furthermore, for the first time volcanic structures including cones have been recognized far from the current rift zone. Although the achieved data are still incomplete and the recognized structures are pieces of a complicated puzzle, they contribute to highlight the multistage evolution of the Mount Cameroon area. In particular, the volcanic cones and the remains of previous craters recognized in the Onge-Bomana area and Limbe-Mabeta Massif indicate that the Mount Cameroon area was first probably characterized by a predominantly effusive magmatic activity. The distribution of the cones along the torch-shaped current rift area, the topographic bulges (SE and SW slope) and the swell (Bokosso fault 1) suggest that the intrusive magmatic activity then also shaped the discontinuous and irregular latero-vertical development of the current volcano. In summary, the recognized structures 1-support the morphotectonic evolution of the Cameroon area here depicted for the first time and 2-suggest to dismiss the previous hypotheses on the evolution of the Cameroon of Monte, based on the key role of the superficial tectonic structures.