Passive Margins: Tectonics, Sedimentation and Magmatism
CONTAINS OPEN ACCESS
This volume has evolved from papers written in memory of Professor David Roberts. They summarize the key findings of recent research on passive margins, from tectonics, bathymetry, stratigraphy and sedimentation, structural evolution and magmatism. Papers include analyses of the central and southern Atlantic margins of South America and Africa, papers on magmatism and extension in the NE Brazilian margin and on the Cote de Ivoire margin, rift architectures of the NW Red Sea margin, tectonics of the eastern Mediterranean margin, salt tectonics of passive margins of the Gulf of Mexico and Brazil, and papers on the NW Shelf margin of Australia. The volume provides readers with new insights into the complexities of passive margin systems that are in reality, not so passive.
Contourites along the Iberian continental margins: conceptual and economic implications
Published:May 09, 2020
Estefanía Llave, F. Javier Hernández-Molina, Marga García, Gemma Ercilla, Cristina Roque, Carmen Juan, Anxo Mena, Benedict Preu, David Van Rooij, Michele Rebesco, Rachel Brackenridge, Gloria Jané, María Gómez-Ballesteros, Dorrik Stow, 2020. "Contourites along the Iberian continental margins: conceptual and economic implications", Passive Margins: Tectonics, Sedimentation and Magmatism, K. R. McClay, J. A. Hammerstein
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This work uses seismic records to document and classify contourite features around the Iberian continental margin to determine their implications for depositional systems and petroleum exploration. Contourites include depositional features (separated, sheeted, plastered and confined drifts), erosional features (abraded surfaces, channels, furrows and moats) and mixed features (contourite terraces). Drifts generally show high- to moderate-amplitude reflectors, which are cyclically intercalated with transparent layers. Transparent layers may represent finer-grained deposits, which can serve as seal rocks. High-amplitude reflectors (HARs) are likely to represent sandier layers, which could form hydrocarbon reservoirs. HARs occur on erosive features (moats and channels), and are clearly developed on contourite terraces and overflow features. Most of the contourite features described here are influenced by Mediterranean water masses throughout their Pliocene and Quaternary history. They specifically record Mediterranean Outflow Water, following its exit through the Gibraltar Strait. This work gives a detailed report on the variation of modern contourite deposits, which can help inform ancient contourite reservoir interpretation. Further research correlating 2D and 3D seismic anomalies with core and well-logging data is needed to develop better diagnostic criteria for contourites. This can help to clarify the role of contourites in petroleum systems.