Pico da Cabrita

Geosite, on the northern road. The undersea volcanic rocks of the island's submarine mountain phase are exposed here: angular fragments of basalt shattered by the thermal shock of lava meeting sea water, cemented into a yellowish breccia. The oldest known on the island are about 19.3 million years old. That this submarine deposit now sits at 200 m of altitude is due to the uplift of the whole island as a block. These rocks, known locally as pedras pretas, were quarried for decades to make pozzolana.