Geology of Martin Vaz Island, South Atlantic, Brazil

<p>Martin Vaz Island is one of the oceanic islands of the homonym archipelago linked to the Vitoria-Trindade volcanic seamount ridge, an important South Atlantic physiographic feature. It is located at 20°28′28″S latitude and 28°51′05″W longitude, approximately 1200 km away from the Brazilian coast. Its geology is an important preserved indicator of Pleistocene alkaline volcanic activities.</p> <p>This work presents lithologic mapping and microscopic observations of Martin Vaz Island rocks. The geological map was developed and prepared at the 1:5000 scale using Esri ArcGIS. Some geological features and structures can be highlighted: two necks, several phonolite dykes and sub-horizontal layers formed by phonolitic pyroclastic rocks and basanites.</p>