Chronostratigraphy and Composite Standard Databases, from Example Application for the Timing of Rifting of the Cote D’Ivoire Margin

Paul J. Sikora and Raymond Levey
Energy & Geoscience Institute, University of Utah, Salt Lake City, UT

Even for an experienced geoscientist studying a given rock section, it is easy to fall into the mindset that the evident strata represents a complete record of the depositional history of the region. In fact, almost every section presents only a partial record containing major hiatuses without any surviving depositional record. Chronostratigraphy details the temporal history of such stratigraphic successions, allowing for the determination of the duration of hiatuses present. One chronostratigraphic methodology with a long history of success is the Composite Standard Database constructed via graphic correlation. A section is composited to the database via a line of correlation drawn upon a graphic representation of in-common stratigraphic datums. Successful calibration will define the age of strata and duration of hiatuses within the section with resolution up to 50-100kyr, depending upon data quality. The line of correlation represents a quantitative representation of the section chronostratigraphy that can be directly integrated to other geologic data sets.

An example of this integrative approach is provided by a study of the timing of rifting of the Cote d’Ivoire continental margin. Graphic analysis of biostratigraphic, sedimentologic and paleomagnetic data from three Ocean Drilling Project Sites, as well an industry well from the Cote d’Ivoire continental shelf are calibrated and integrated via graphic correlation against a West African Composite Standard Database. Temporal calibration of this data set allows for construction of high-resolution paleoenvironmental maps for various time slices during the Lower to Upper Cretaceous syn-rift to post-rift period of deposition on the Cote d’Ivoire margin that leads to better understanding of the timing of establishment of shallow and deepwater connections between the North and South Atlantic Basins.

AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery