Brava Island (Cabo Verde, West Africa): Great Volcanic Geodiversity on a Tiny Ocean Island
摘要
Brava Island, the westernmost island in the south branch of the Cabo Verde archipelago (West Africa), presents geological and geomorphological evidence that demonstrates the existence of varied recent active volcanism, having been responsible for building the current geodiversity. This work identifies, characterizes and proposes 16 sites displaying geoheritage value within the three major volcano stratigraphic units (Lower, Middle and Upper units). Together, these 16 proposed geological heritage sites (12 representing volcanic deposits and 4 representing volcanic landforms) reflect diverse episodes of volcanism, ranging in emplacement environment from submarine volcanism to subaerial volcanism and in composition from carbonatitic, phonolithic to mafic. Brava stands out for the occurrence of carbonatites associated with both the intrusive complex and the terminal phases of magmatism, where they have extrusive (effusive and explosive) characteristics and calcic composition. Such a large geodiversity on a tiny young island (64 km2 and < 3 Ma of age) makes Brava a very attractive location for research and training activities related to volcanism and volcanic hazards. It is also an important reference in the context of the inventory of Africa’s geological heritage.