Genesis of the anticline structures of the northeast block of the Recôncavo Basin, Brazil

Abstract

The Recôncavo Basin was formed in Gondwanaland during Mesozoic times and is located in northeastern
Brazil. Its geometry is of a half-gmben dipping ESE towards the main depocenter. Tmnsfer faults divide the basin into
three blocks named South, Central and Northeast. Important oil fields stand out in the Northeast block associated with
anticline features. The formation ofthese anticlines resulted, in most cases, from the accommodation to a listric geometry
or ramp-f1at-rampsystem of the detachment fault plane in an extensional environment. On the other hand, one of them
has been found to be a restricted transpressional feature. Final/y, there is a case in which the anticline was formed due
to accommodation to a basement high combined with the rotation of the Northeast block. A portion of these anticlines
was formed during sedimentation as demonstrated by the thinning of the stratigraphic intervals towards the apex of the
fold. The other portion originated after sedimentation based on the constant thickness of the stmtigraphic interval along
the structures. AI/ possibility of a genesis of the anticlines by differential compaction was discarded.