A NATUREZA E DISTRIBUIÇÃO DAS OCORRÊNCIAS DE APATITA DA ÁREA IPIRÁ-PEDRAS ALTAS, NORDESTE DO ESTADO DA BAHIA

Resumo

The geological studies developed by CPRM to the DNPM in the Apatita and Bahia II Projects in the Pedras Altas-Ipirá areas, Northeastern Bahia, identified belts of diopsidic rocks as the main depositories of apatite mineralization. Segments of tectonic plates related to Transamazonic and Guriense events border laterally the area in focus, delimitting zones of predominance of such calc-sillicated rocks. It is admitted the interaction of two genetic processes in the formation of apatite: 1) from an old sedimentary origin of calc-pelitic nature, in disseminated form, and 2) by later metassomatic processes, related to the emplacement of syenitic pegmatites which cut the calc-sillicatic sequences and constitute remobilized zones with concentrations in the form of lodes, lenses and pods. It is suggested, to the first case, supplementary investigations in order to set up its economic importance.