Portal de Periódicos da CAPES

Artigo Acesso aberto Produção Nacional

BIBTEX RIS

Cryogenian U-Pb (SHRIMP I) zircon ages of anorthosites from the upper sequences of Niquelândia and Barro Alto Complexes, Central Brazil

2007; Sociedade Brasileira de Geologia; Volume: 37; Issue: S4 Linguagem: Inglês

10.25249/0375-7536.200737s47075

2177-4382

Ciro Teixeira Correia, Vicente Antônio Vitório Girardi, Miguel Ângelo Stipp Basei, Allen P. Nutman,

Mineralogy and Gemology Studies

The Niquelândia Complex comprises two main superposed sequences dipping westward: the lower (LS), at the eastern, and the upper (US), at the western part of the body. The Complex is either interpreted as a single body, or as two distinct unrelated layered massifs. New SHRIMP U-Pb determinations on igneous zircon grains of anorthosites from Niquelândia US and from the upper portion of the Barro Alto Complex indicate crystallization ages of 833 ± 21 Ma and 733 ± 25 Ma, respectively, thus supporting Cryogenian Neoproteroic ages for the igneous crystallization of the US unit of Niquelândia and for the Barro Alto anorthosites.