Valorization of phlogopite ore by geochemical analysis and interpolation with Aster satellite images (case of Ampandrandava - South of Madagascar)

Abstract

Phlogopite is one of the oldest industrial minerals exploited in southern Madagascar. From Ihosy to Fort Dauphin, there are several types of farmers who live from the artisanal exploitation of phlogopite with various underground mica mines abandoned before 1940. Currently, it is exploited almost everywhere in the south of Madagascar. This irrational exploitation, without specific characterization makes this mineral cheap, likewise destroys the environment and leads to waste of the deposit. Ampandrandava is one of those former semi-mechanized underground mines still in operation, and is the only underground mine on the island. With a depth of at least 100m, this mine is characterized by its different minerals and unique phlogopite. In order to develop this mineral and to include this mine among the mining heritage in Madagascar, it is important to characterize its products and value the mine and the existing minerals in the town. The analysis of the samples and the interpretation of the geochemical data of this mineral associated with analyzes of ASTER satellite images will allow us to know its mineral specification as well as the value of the mine. The results of this process will show a correlation to the distribution of this mineral in the study area. The interpolation with the relevant lithological information and the mineralization indices shows a homogeneity of the results obtained. However, these results provide a new layer of information that can be used for the detection of favorable lineaments for a new exploitation.