Sediment Routing From Shelf to Basin Floor in the Quaternary Golo System of Eastern Corsica
How and when sediment moves from shallow marine to deep-water environments is important for understanding the evolution of continental margins and exploring for hydrocarbons in offshore basins. The linked depositional system of the Golo River, Delta, Canyons and Fans provided us with a unique opportunity to study sediment routing in a relatively compact depositional system using an array of high-frequency seismic data, multi-beam bathymetry and five, long cores for lithology and age control. Over the last 400,000 years a series of sand-rich submarine fans developed when sea level dropped below about -80m relative to current sea level and the Golo River, or its delta came into contact with one of two shelf-penetrating submarine canyons. During periods of higher sea level, sand deposition on the fans ended, but relatively thick deposits of silt, clay and carbonate-rich sediment blanketed the deep basin. Deposition rates in the basin ranged from 0.12 m/ka to 0.40 m/ka over the last 450 ka. Mud deposition rates remained relatively constant around 0.16 m/ka at all times while sand deposition only happened during periods of low sea level (- 80 m below present day sea level) with an average rate of 0.21 m/ka. Mud was deposited as sheets up to 10 m thick that draped inactive fans, as levees and as fringes of active fans. Sand and coarser sediments were confined to the fills of submarine canyons, active submarine channels and as lobes at the mouths of channels.
AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019