The volcanic-subvolcanic rocks of the fernando de noronha archipelago, southern atlantic ocean: Mineral chemistry

Fernando de Noronha Archipelago exhibits a diverse volcanic and subvolcanic rock composition characterized by two distinct alkaline series: sodic (undersaturated) and potassic (mildly undersaturated to silicic). The study reveals the presence of unique mineral assemblages, including magnesium olivines, melilites, clinopyroxenes ranging from salites to aegirines, amphiboles, dark micas with high BaO content, and feldspars such as calcic plagioclases, sanidines, and anorthoclases. Nephelinites and basanites with mantle xenoliths are also notable. The research employs mineral chemistry analysis to elucidate the geological processes shaping these rocks, providing insights into their petrogenesis and the complex volcanic history of the archipelago.

Lopes, R., Ulbrich, M., & Ulbrich, H. (2014). The volcanic-subvolcanic rocks of the fernando de noronha archipelago, southern atlantic ocean: Mineral chemistry. Open Geosciences, 6(4), 422–456. https://doi.org/10.2478/s13533-012-0195-7