Iniciar sessão

Navegar para Cima
Instituto de Investigação
em Vulcanologia e Avaliação de Riscos
Última hora:

Livros ► Capítulos


Referência Bibliográfica

CARMO, R., MADEIRA, J., FERREIRA, T., QUEIROZ, G., HIPÓLITO, A. (2015) – Volcano-tectonic structures of S. Miguel Island, Azores. In: Gaspar, J.L., Guest, J.E., Duncan, A.M., Barriga, F.J.A.S., Chester, D.K. (eds.) Volcanic Geology of São Miguel Island (Azores Archipelago), Geological Society of London Memoir, 44: 65-86, doi: 10.1144/M44.6.​


​The Azores archipelago is located at the triple junction between the Eurasia, Nubia and North America lithospheric plates. o Miguel Island, situated at the southeastern part of the western segment of the Azores–Gibraltar Fracture Zone, presents an east–west elongated shape, comprising three quiescent central volcanoes with summit calderas linked by zones of fissure volcanism. The eastern part of the island is older and inactive. Active faulting is represented by prominent fault scarps that constitute important extensional structures, or by linear volcanic structures in fissural volcanic zones, with a dominant NW–SE to WNW–ESE trend. Although less frequent, there are also NNW–SSE to north–south, NE–SW and east–west faults, reflected by some volcanic alignments and linear segments of the drainage system and sea cliffs. The geometric and kinematic data are in agreement with that observed in the rest of the archipelago. However, at eastern Sa˜o Miguel Island data indicate two distinct groups of conjugated faults characterized by three-dimensional strain: NW–SE to WNW–ESE normal dextral structures are conjugated with NNW–SSE normal left-lateral faults and NW–SE to WNW–ESE normal left-lateral faults are conjugated with NE–SW normal dextral structures, showing the presence of two different stress fields separated in time.