Trindade hotspot

The Trindade hotspot is a working hypothesis supposing that the submarine volcanic chain Vitória-Trindade, off the eastern coast of Brazil in the southern Atlantic Ocean, is a volcanic hotspot chain. It was considered that the supposed hot-spot should be responsible for the creation of the east-west trending Vitória-Trindade seamount chain, which includes the Trindade and Martim Vaz archipelago at its easternmost end. Trindade, a small island in the archipelago, is the hotspot's most recent eruptive center.

The Trindade hotspot is marked 41 on the map

This idea was based on the geochemical data, especially of the highly silica-undersaturated alkaline ultramafic rocks of the Trindade Island and Martim Vaz Island. The isotopic data is OIB-type, which is favourable to the hot-spot hypothesis. However, the volcanic chain direction is E-W and the absolute motion vector of the South America Plate is NW. Therefore, the volcanic chain cannot be a hot-spot chain. Recent research papers, such as Skoletnev, Peyve & Truko 2010 and Motoki, Motoki & Melo 2012, proposed that the hot mantle penetrated horizontally along the Vitória-Trindade fracture zone which is present in the lithospheric mantle. Because of the same reason, the Fernando de Noronha Volcanic chain also is not a hot-spot chain. On the other hand, the NW-SE magmatic alignments, such as the Cruzeiro do Sul Chain, Bahia Chain, and Macau-Queimado, are considered to be hot-spot chains.

References

• Motoki, A.; Motoki, K. F.; Melo, D. P. (2012). "Caracterização da morfologia submarina da Cadeia Vitória-Trindade e áreas adjacentes, ES, com base na batimetria predita do TOPO versão 14.1". Revista Brasileira de Geomorfologia (in Portuguese). 13 (2): 151–170. doi:10.20502/rbg.v13i2.195. ISSN 2236-5664. Retrieved May 17, 2015.
• Skoletnev, S. G.; Peyve, A.; Truko, N. N. (2010). "New data on the structure of the Vitoria-Trindade seamount chain (western Brazil basin, South Atlantic)". Doklady Earth Sciences (in Portuguese). 431 (2): 435–440. Bibcode:2010DokES.431..435S. doi:10.1134/S1028334X10040057. S2CID 129392560.