Geology and U-Pb geochronology of the Banabuiu granite, Northeastern Ceara, Brazil

作者：Lima M N^*; Nogueira Neto J A; Azevedo M R; Valle Aguado B

来源：Estudios Geologicos, 2010, 66(1): 35-44.

DOI：10.3989/egeol.40196.113

• Brasilian Orogeny
• two-mica granites
• U-Pb geochronology

The Banabuiu massif crops out in the Central Ceara Domain (DCC) of the Borborema Province (NE Brasil), as an N-S elongate granite intrusion, concordant with the regional structures. It was emplaced into basement rocks of Paleoproterozoic age, extensively transformed into gneisses and migmatites during the Brasilian orogeny (similar to 600 Ma). Using U-Pb zircon dating, the crystallization age of the Banabuiu syn-kinematic two-mica granite was estimated at 578.6 +/- 6.5 Ma. The granite is strongly peraluminous (A/CNK = 1,098-1,134) and shows a typical S-type geochemical signature. The epsilon Nd(580) values are strongly negative (epsilon Nd(580) = -19 a -23) and partially overlap with those of the Paleoproterozoic gneissmigmatite complex (epsilon Nd(580) = -12 to -26), suggesting that the parental magmas of the Banabuiu granite could have been produced by partial melting of similar crustal materials.

• 出版日期2010