Data/hora: 13/06/2024 15:26:28

Provedor de dados: 	42	
País: 	Brazil	
Título: 	C-, Sr-isotope stratigraphy of carbonate rocks from the Southern Espinhaço Ridge, Minas Gerais, southeastern Brazil	
Autores: 	FRAGA,LUCIO M.S.; NEVES,SORAYA C.; UHLEIN,ALEXANDRE; SIAL,ALCIDES N.; PIMENTEL,MARCIO M.; HORN,ADOLF H.	
Data: 	2014-06-01	
Ano: 	2014	
Palavras-chave: 	Sr isotopes; C isotopes; Carbonates; Macaúbas Group; Bambuí Group; Marinoan glaciation.	
Resumo: 	Neoproterozoic carbonate rocks comprise different stratigraphic units in the southern part of the Espinhaço Ridge, Minas Gerais, Brazil. C, O- and Sr-isotope analyses were carried out along four selected stratigraphic sections across these formations. These are: (i) the Rio Pardo Grande Formation in the upper portion of the Espinhaço Supergroup, sampled in section 3; (ii) Macaúbas Group laminated limestones (Tijucuçu Farm) and dolostone layers (Domingas Formation) have been respectively sampled along the so-called sections 1 and 2, and (iii) the lower stratigraphic units of the Bambuí Group, sampled in section 4. Laminated limestone samples from the Macaúbas Group have δ13C values as high as 10.9‰ decreasing up section to -1.1‰ and 87Sr/86Sr values vary from 0.7072 to 0.7076, a range commonly observed in Cryogenian rocks. In section 2, dolomitic samples exhibit 87Sr/86Sr from 0.7076 to 0.7077 while in section 3, 87Sr/86Sr from 0.7074 to 0.7079. In section 4, 87Sr/86Sr values are around 0.7080. The values of 87Sr/86Sr observed in carbonate samples from the Macaúbas Group are similar to those observed in the Sr-isotope secular curve for the Neoproterozoic. Carbonate samples from the base of the Bambuí Group correlate with Ediacaran fingerprints, after the Marinoan (ca. 635 Ma) glaciation.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000200633	
Editor: 	Academia Brasileira de Ciências	
Relação: 	10.1590/0001-3765201420130152	
Formato: 	text/html	
Fonte: 	Anais da Academia Brasileira de Ciências  v.86 n.2 2014	
Fonte: 	info:eu-repo/semantics/openAccess