REE signatures from pyroxenes of Passira anorthositic complex, Borborema province - NE Brazil - Accioly, Ana Claudia de Aguiar; McReath, Ian; Vannucci, Riccardo; Zannetti, Alberto; Bottazzi, Piero; Santos, Edilton José dos; Guimarães, Ignez de Pinho; Santos, Almany Costa (International Geological Congress, 2004)