BackgroundThe 20 x 40 km dominantly volcanic island of Santo Antao is the NW-most of the Cape Verde Islands. Volcanic activity dates back to the Pliocene and continued into the late Pleistocene. A large 7-km-wide E-facing depression, Cha de Morte, was thought at one point to be a caldera, but was later interpreted as an erosional feature. Much of the island is covered by phonolitic pumice deposits of the Cao Grande Pumice, erupted about 200,000 years ago. The youngest eruptive products are lava flows that originated from vents at Cha de Lagoa in the central part of the island, just south of the NE-SW axial ridge. The lava flows cover an area of 40 km2 and reached the SE coast just SW of the coastal village of Porto Novo. These flows were initially considered by Mitchell-Thome (1976) to be Holocene in age based on morphological evidence, but later 40Ar/39Ar dating by Plesner et al. (2003) for these lava flows produced an age of 90,000 +/- 30,000 years.
Source: Smithsonian / GVP volcano information
See also: Sentinel hub | Landsat 8