Idade (Pb-Pb) e aspectos petrográficos e litogeoquímicos do Complexo Alcalino Floresta Azul, Sul do Estado da Bahia

摘要: Pb-Pb AGE AND PETROGRAPHIC LITHOGEOCHEMICAL ASPECTS OF THE FLORESTA AZUL ALKALINE COMPLEX, SOUTHERN STATE BAHIA The Floresta Azul Alkaline Complex (CAFA), is represented by a NE-SW elongated igneous body, with an exposed area of 200 km 2 , located in the central-northern region Southern Bahia State Province. Two types magmatic intrusion were recognized: (i) at eastern part complex, occur granitic rocks, presenting many dior itic inclusions, and (ii) syenitic rocks are western region. ages obtained single zircon crystals from g ranite (696 ± 11 Ma); diorite (688 Ma) syenite 10 indicate that CAFA emplaced synchronously during Neoproterozoic event. main mafic mineral biotite, whereas sodic amphibole aegirine sporadically foun d lithotypes. textural features these typified angular distribution well-for med feldspar crystals, reflect lack significant deformation after crystallization. All lithologic complex have alk aline signature, characterized high contents Nb (86-243 ppm), Y (22-43ppm), F (760-2600) Cl (220-10.000). distribut ion patterns minor trace elements suggest different cogenetic.