Petrographical and Geochemical Characteristics of the Mauritanides Belts’ Birbirites
The Gouérarate region represents the most important area of birbirites’ outcrops, sited in the Mauritanides Belts. In this paper, the petrological description of such facies is highlighted. The Gouérarate Birbirites are mainly composed of silica (chalcedony and microquartz) and talc, geochemically characterized with high SiO2 level (up to 80%). They are derived from a highly refractory peridotite and serpentinite, which correspond to former dunite, harzburgite and serpentinite. The birbirites are mainly formed of ultramafic rocks’ weathering, which has resulted in the concentration of SiO2 and the transformation of olivine, pyroxene and serpentines into chalcedony, quartz and talc.
KeywordsMauritanides belts Birbirites Peridotites Serpentinites Weathering
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