U–Pb perovskite ages for brazilian kamafugitic rocks: further support for a temporal link to a mantle plume hotspot track |
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| Authors: | Patrícia B A Sgarbi Larry M Heaman Jos Carlos Gaspar |
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| Institution: | a Department de Geologia IGC, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627-B, Horizonte 31270-901, Brazil;b Dept. of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada, T6G 2E3;c Instituto de Geociências, Universidade de Brasília, 70910-900, Brasília, DF, Brazil |
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| Abstract: | We present the results of a U–Pb perovskite age study of kamafugites from Mata da Corda (MC) and Santo Antônio da Barra (SAB), Minas-Goiás alkaline province, Brazil. Perovskite crystals were separated from MC mafurites, ugandites, and cognate pyroxenites, as well as from SAB melilite mafurite. The range of ages of Brazilian kamafugitic samples is 15 Ma. The 206Pb/238U perovskite ages generally cluster into three age groupings: 88–90, 80–81, and 75–76 Ma. The two younger periods of kamafugitic magmatism occur in the MC area, whereas the older samples are from the SAB area. These new age results provide the first robust evidence of a progressive eastward younging of mafic alkaline magmatism, most likely related to a mantle plume hotspot track. |
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| Keywords: | Brazil Cretaceous Kamafugite Minas-Goias alkaline province U– Pb perovskite ages |
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