DUCTILE DUPLEXING AT A BEND OF A CONTINENTAL-SCALE STRIKE-SLIP SHEAR ZONE - EXAMPLE FROM NE BRAZIL

During the Pan-African orogeny, the Borborema Province in NE Brazil de veloped a continental-scale shear-zone system that comprises NE- and E W-trending ductile strike-slip shear zones. Remote sensing and structu ral mapping has revealed a pattern of arcuate anastomosing strike-slip shear zones separating sigmoidal lenses of less deformed material, lo cated at the western end of the EW-trending Patos shear zone, which is one of the largest shear zones of the Province. This structure of imb ricate shear zones was initiated under high-temperature deformation co nditions. It is interpreted as a ductile strike-slip duplex and may re present a kinematic pattern for strain accommodation in response to a bend of a ductile mega-shear zone.