SULFETOS DO COMPLEXO GABRÓICO CANINDÉ, SISTEMA OROGÊNICO SERGIPANO

Sulphides of the Canindé Gabroic Complex, Sergipano Orogenic System

Abstract

The Canindé Domain, located in the northern part of the Sergipano Orogenic System, is composed of metavulcanic and metassedimentary rocks of the Canindé Complex, which are intruded by a gabbroic body, named as the Canindé Gabbroic Complex. The occurrence of Cu-Ni sulfide mineralization in the gabbroic rocks was already documented, and is described in detail, with respect to its mineralogy and mineral chemistry, through the utilisation of optical microscopy of transmitted and reflected light, scanning electron microscopy and electronic microprobe. The analyses by these micro-analytical methods permitted us to identify pyrite, chalcopyrite, pyrrhotite, pentlandite, sphalerite, violarite (FeNi₂S₄) and spionkopita (Cu₃₉S₂₈) in the samples of gabbros which were collected on outcrops of the Canindé Gabbroic Complex. Violarite and spionkopite were not previously described in the Canindé Domain. Evidences of late hydrothermal alteration of the gabbros point to the genesis of the secondary minerals violarite and spionkopite by alteration of the primary Ni and Cu sulfides respectively.