New 40Ar/39Ar ages and revised 40K/40Ar* data from nephelinitic–phonolitic volcanic successions of the Trindade Island (South Atlantic Ocean)

The Trindade Island is located in the South Atlantic Ocean, 1170km from the Brazilian coast and represents the eastern end of the submarine E-W Vitória-Trindade Chain. This is interpreted as the Trindade plume track beneath the South American plate during the Cenozoic. Almeida (1961) recognized five...

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Main Authors: Pires, G., Bongiolo, E., Geraldes, M., Renac, C., Santos, A., Jourdan, Fred, Neumann, R.
Format: Journal Article
Published: Elservier 2016
Online Access:http://hdl.handle.net/20.500.11937/19943
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author Pires, G.
Bongiolo, E.
Geraldes, M.
Renac, C.
Santos, A.
Jourdan, Fred
Neumann, R.
author_facet Pires, G.
Bongiolo, E.
Geraldes, M.
Renac, C.
Santos, A.
Jourdan, Fred
Neumann, R.
author_sort Pires, G.
building Curtin Institutional Repository
collection Online Access
description The Trindade Island is located in the South Atlantic Ocean, 1170km from the Brazilian coast and represents the eastern end of the submarine E-W Vitória-Trindade Chain. This is interpreted as the Trindade plume track beneath the South American plate during the Cenozoic. Almeida (1961) recognized five volcanogenic successions at Trindade in decreasing age: the Trindade Complex (TC) and the Desejado (DF), Morro Vermelho (MV), Valado (VF) and Paredão (PF) formations, composed of nephelinitic to phonolitic effusive-pyroclastic deposits, dykes and necks. Here, we present new 40Ar/39Ar ages and re-evaluation of available 40K/40Ar* data that, coupled with previous petrological information, allowed us to reconstruct the volcanic history of the island (i.e., 3.9-0.25Ma) distinguishing near synchronous volcanic episodes and solving several stratigraphic uncertainties reported in the literature.The geochronological dataset show that the nephelinitic-phonolitic volcanism at Trindade was discontinuous throught time, being marked by periods of high volcanic activity and periods of quiescence, which suggests variable melt production and eruption rates. The peak of the volcanic activity occurred between 3.9 and 2.5. Ma (i.e., Lower Pliocene to Lower Pleistocene) that is represented by the TC, which correspond to the largest volume of volcanic deposits preserved in the island. The volcanic activity slows down progressively from 2.5. Ma to cease at ca. 1.6. Ma, period that is represented by the DF. This volcanism was followed by a quiescent period that lasted until the ephemeral nephelinitic volcanism of the MV (no age), VA (no age) and PF (ca. 0.25. Ma). Thus, the volcanic activity in Trindade was ceased completely at ca. 0.25. Ma, event registered in the uppermost volcanic deposits of the PF and that represents the last volcanic activity in the Brazilian territory.
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spelling curtin-20.500.11937-199432017-09-13T15:37:43Z New 40Ar/39Ar ages and revised 40K/40Ar* data from nephelinitic–phonolitic volcanic successions of the Trindade Island (South Atlantic Ocean) Pires, G. Bongiolo, E. Geraldes, M. Renac, C. Santos, A. Jourdan, Fred Neumann, R. The Trindade Island is located in the South Atlantic Ocean, 1170km from the Brazilian coast and represents the eastern end of the submarine E-W Vitória-Trindade Chain. This is interpreted as the Trindade plume track beneath the South American plate during the Cenozoic. Almeida (1961) recognized five volcanogenic successions at Trindade in decreasing age: the Trindade Complex (TC) and the Desejado (DF), Morro Vermelho (MV), Valado (VF) and Paredão (PF) formations, composed of nephelinitic to phonolitic effusive-pyroclastic deposits, dykes and necks. Here, we present new 40Ar/39Ar ages and re-evaluation of available 40K/40Ar* data that, coupled with previous petrological information, allowed us to reconstruct the volcanic history of the island (i.e., 3.9-0.25Ma) distinguishing near synchronous volcanic episodes and solving several stratigraphic uncertainties reported in the literature.The geochronological dataset show that the nephelinitic-phonolitic volcanism at Trindade was discontinuous throught time, being marked by periods of high volcanic activity and periods of quiescence, which suggests variable melt production and eruption rates. The peak of the volcanic activity occurred between 3.9 and 2.5. Ma (i.e., Lower Pliocene to Lower Pleistocene) that is represented by the TC, which correspond to the largest volume of volcanic deposits preserved in the island. The volcanic activity slows down progressively from 2.5. Ma to cease at ca. 1.6. Ma, period that is represented by the DF. This volcanism was followed by a quiescent period that lasted until the ephemeral nephelinitic volcanism of the MV (no age), VA (no age) and PF (ca. 0.25. Ma). Thus, the volcanic activity in Trindade was ceased completely at ca. 0.25. Ma, event registered in the uppermost volcanic deposits of the PF and that represents the last volcanic activity in the Brazilian territory. 2016 Journal Article http://hdl.handle.net/20.500.11937/19943 10.1016/j.jvolgeores.2016.09.020 Elservier restricted
spellingShingle Pires, G.
Bongiolo, E.
Geraldes, M.
Renac, C.
Santos, A.
Jourdan, Fred
Neumann, R.
New 40Ar/39Ar ages and revised 40K/40Ar* data from nephelinitic–phonolitic volcanic successions of the Trindade Island (South Atlantic Ocean)
title New 40Ar/39Ar ages and revised 40K/40Ar* data from nephelinitic–phonolitic volcanic successions of the Trindade Island (South Atlantic Ocean)
title_full New 40Ar/39Ar ages and revised 40K/40Ar* data from nephelinitic–phonolitic volcanic successions of the Trindade Island (South Atlantic Ocean)
title_fullStr New 40Ar/39Ar ages and revised 40K/40Ar* data from nephelinitic–phonolitic volcanic successions of the Trindade Island (South Atlantic Ocean)
title_full_unstemmed New 40Ar/39Ar ages and revised 40K/40Ar* data from nephelinitic–phonolitic volcanic successions of the Trindade Island (South Atlantic Ocean)
title_short New 40Ar/39Ar ages and revised 40K/40Ar* data from nephelinitic–phonolitic volcanic successions of the Trindade Island (South Atlantic Ocean)
title_sort new 40ar/39ar ages and revised 40k/40ar* data from nephelinitic–phonolitic volcanic successions of the trindade island (south atlantic ocean)
url http://hdl.handle.net/20.500.11937/19943