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Deformação neógena e suas implicações na estruturação dos campos de petróleo na região de Icapuí-Ponta Grossa (CE), Bacia Potiguar emersa

2008; Sociedade Brasileira de Geologia; Volume: 38; Issue: 2 Linguagem: Inglês

10.5327/rbg.v38i2.1395

2317-4889

Débora do Carmo Sousa, Emanuel Ferraz Jardim de Sá, Alex Francisco Antunes,

earthquake and tectonic studies

In coastal cliffs at the western portion of the Potiguar Basin (so-called Aracati Platform), the Barreiras Formation, of miocene age, displays structures pointing to high strain deformation. Detailed mapping of faults and folds geometry in the Barreiras Formation leds to recognition of extensional structures (at Ponta Grossa village) and contractional oblique structures (Vila Nova, next to Icapui town), both of them related to a transcurrent system bearing NE (at these locations) and NW trends (Afonso Bezerra Fault, in the central portion of the basin). These data point to a neogene stress field which generated faults, folds and hydroplastics structures, including SL fabrics and shear zones, as well as reactivated older structures in the underlying neocretaceus sedimentary section. Reinterpretation of seismic sections from this region and other geological data at several places in the Potiguar Basin outline structures which are correlated (in style and kinematic regime) throughout the siliciclastic rocks of the Acu Formation, limestones of the Jandaira Formation and younger basalts of the Macau Formation, whose age straddles the Oligocene-Miocene boundary. This structural framework recognized at the surface has to be compatible with subsurface deformation as observed in seismic sections, which includes pulses/events of older, Neocretaceus to Paleogene age. This model has important implications as regards the structure (geometry, kinematics, age op traps) of oil reservoirs (especially the sandstones of the Acu Formation, in the Fazenda Belem Oil Field) and the processes of migration and hydrocarbon entrapment at this region of the Potiguar Basin.