Seismic stratigraphy of rift basins: techniques, methods and its application in the Recôncavo Basin

Abstract

This paper aims a proposal of interpretation and seismic stratigraphy systematic mapping of rift basins based on genetic concepts, as offered by the basic development of the Sequence Stratigraphy – the temporal interpretation of units based on concepts derived from variables and observable in depositional trends. So, rift basins are controlled by specifically variables and its relationships, which results in theoretical evolutional models. Those theoretical models are detailed as depositional trends denominated stacking patterns. Thus, from the stacking patterns, it is able to establish the inverse way analysis, pictur-ing evolutional models and controlling variables. The main objective of this paper is the migration of the genetic tectonic-stratigraphic model of rift basins to the seismic platform, supported by the key-concepts of the seismic stratigraphy. This analysis is based on the recognition of seismic stratigraphic units which composes the tectonic system tracts – basic units of the framework, and these system tracts are formed by specific stacking patterns for each portion of the half graben. As those stacking patterns reflect changes in the accommodation, stratigraphic sur-faces and strata termination patterns are established. Therefore, a whole conceptual basis of seismic stratigraphy recognition and mapping is proposed, as well as a time determination of evolutional models in chronoestratigraphic diagrams (Wheeler charts), to supply a useful tectonic-stratigraphic framework to hydrocarbon exploration.