CAMPO DE ESFORÇOS PLIO-PLEISTOCÊNICO NA ILHA DA TRINDADE (OCEANO ATLÂNTICO SUL, BRASIL) E SUA RELAÇÃO COM ATECTÔNICA REGIONAL

• DOI: 10.5327/rbg.v29i2.683
• Publication Date: 1999-01-01
• Authors: André Luiz Ferrari; Cláudio Riccomini
• Keywords: Dike; Basement; Plio-Pleistocene

The volcanic island of Trindade, alkaline nature, is the emerged portion a large building whose base submerged about 5000 m depth. analysis pattern orientation Pliocene-Pleistocene dike swarm northeast island, as well lengthening phonolithic plugs, has allowed determination an NW direction SH max (in case corresponding to σ1) during emplacement intrusive bodies, compatible with ENE-WSW E-W right-lateral binary. determined for σ1 in parallel larger axis building, suggesting same tectonic control its formation. On other hand, Vitoria-Trindade Chain shows differentiated segments NW-SE, NE-SW and directions, probably changes Tertiary this oceanic South American Plate. These are partly variations verified adjoining continental Southeastern Brazil. Differences depth basement north south corroborate behavior fracture zone, that would have acted conduit magmatism associated Trindade Plume. incompatibility between expected Pliocene Pleistocene Island studied dikes implies non-rigid segment