The Shallow Marine Fluvio-turbidite Systems - A Recent Concept Extended to the Exploration of the Transform Margins
C. Rigollet, V. Vernain-Perriot and D. Brethaut
Event name: 77th EAGE Conference and Exhibition 2015
Session: Geological Processes in Modern Continental Margins and Basins
Publication date: 01 June 2015
Info: Extended abstract, PDF ( 2.21Mb )
Price: € 20
Sandy shallow marine fluvio-turbidite channels observed downstream river mouths, are built by hyperpycnal flows during flood events. They present morphological similarities with the deep-offshore turbidite channels but dissimilar environmental specificities. Several shallow marine channels have been described at the outcrop for three decades and similar systems are observed in the present shallow marine environment on tectonic active margin, such as the well described channel-levee systems fed by the Fraser River and the Squamish River in the Canadian Strait of Georgia forearc basin. All these current and fossil fluvio-turbidite channels have the common characteristics of being linked to river mouths and deposited on the shelf or proximal ramp in a compressional setting with strong sedimentary yield. The sedimentary concept developed from ancient foreland basin has been published in recent years by Professor Mutti and collaborators. Authors recommend to use the terms mixed turbidites or fluvio-turbidites to avoid confusion with their deep offshore cousins. Our observations in subsurface case studies, integrating 3D seismic, wells and core data, support the possible extension of the shallow marine fluvio-turbidite concept to transform margin such as the south Atlantic Equatorial Transform Margins. It opens new exploration theme where the classic models don’t predict sand accumulation.