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LITOGEOQUÍMICA DO BATÓLITO ENDERBÍTICO-CHARNOCKÍTICO DO COMPLEXO JEQUIÉ, NA REGIÃO DE LAJE E MUTUtPE, BAHIA

1994; Sociedade Brasileira de Geologia; Volume: 24; Issue: 1 Linguagem: Inglês

10.25249/0375-7536.19941321

ISSN

2177-4382

Autores

ANDRÉ FORNARI, Johildo Salomão Figueirêdo Barbosa,

Tópico(s)

Fish biology, ecology, and behavior

Resumo

JEQUIÉ COMPLEX, LAJE-MUTUÍPE REGION, BAHIA.The granulitic rocks of the Laje-Mutuípe region are part of an enderbitic-charnockitic batholith that constitutes the most important segment of the Jequié Complex, situated in the southeast part of the State of Bahia.This plutonic body is considered to be intrusive in high grade metamorphic rocks made of acid and basic, and probably ortho-derivated banded granulites.Kinzigites, banded iron forraations, graphitites, garnetiferous quartzites, and granulitic migmatites are intercalated with these granulites.These plutonic rocks have been subjected to at least two deformation episodes in the ductile state: the fïrst (Dl) tangential shearing stress, generated NW-verging overturned folds; the second (D2), also shearing, but of transcurrent nature, developed sub-vertical NNW-SSE foliations/bandings in the rocks.The enderbites, charno-enderbites and charnockites are intermediate and acid rocks, that represent two calc-alkaline series.The first is characterized by lower contents of Ti, Fe, K, P, Rb, Zr, Ba, Y and REE, than the second, which is chemically more mature and probably intrusive into the first.The crystallisation age of these plutonic rocks, obtained through U/Pb measurements in zircons, by the "SHRIMP" (Sensitive High Resolution lonic Microprobe) technique, is situated between 2,700 and 2,800 Ma, being therefore considered of Archean age.

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