Trindade hotspot

The Trindade hotspot is marked 41 on the map

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.

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.