Sedimentary, tectonic, and sea-level controls on submarine fan and slope-apron turbidite systems

Abstract

To help understand factors that influence submarine fan deposition, we outline some of the principal sedimentary, tectonic, and sea-level controls involved in deep-water sedimentation, give some data on the rates at which they operate, and evaluate their probable effects. Three depositional endmember systems, two submarine fan types (elongate and radial), and a third nonfan, slope-apron system result primarily from variations in sediment type and supply. Tectonic setting and local and global sea-level changes further modify the nature of fan growth, the distribution of facies, and the resulting vertical stratigraphic sequences.

Age models for pelagites and turbidites from the Cap Timiris Canyon off Mauritania

“…Weaver and Kuijpers, 1983;Weaver and Rothwell, 1987;Simm et al, 1991;Rothwell et al, 1992;Weaver et al, 1992;Lopez, 2001;Wynn et al, 2002) and perhaps changes in the ocean current system during sea-level low-stands (cf. Shanmugam and Moiola, 1982;Stow et al, 1984;Lopez, 2001). The most detailed record of turbidity current activity at the transition from the last glacial to the Holocene is preserved in the intrachannel core GeoB 8509-2.…”

Sandy turbidite successions at the base of channel-levee systems of the Amazon Fan revealed by FMS logs and cores: unraveling the facies architecture of large submarine fans

“…The Amazon Fan is widely classified as an elongate, mud-rich fan (Stow et al, 1984;Shanmugam and Moiola, 1988;Pickering et al, 1989;Reading and Richards, 1994), yet the sandy character of bedby-bed sections through HARP intervals (Fig. 3, back-pocket foldout) is comparable to many ancient turbidite successions in, for example, foreland basins.…”

The role of deformation processes on the geometry of mud-dominated turbiditic systems, Oligocene and Lower–Middle Miocene of the Lower Congo basin (West African Margin)

“…This morphological difference cannot be solely explained by an eustatic control because sequence stratigraphic models predict higher sediment discharge (i.e. higher erosion potential; Stow et al, 1984) during major eustatic sea-level falls and lowstands.…”

“…It is, however, very complex and refers to numerous additional parameters difficult to individualize such as relative sea-level fluctuations, regional basin tectonics, and rate, type and source of sediment supply (Eschard, 2001;Richards, Bowman, & Reading, 1998). The second parameter is the tectonic setting (Stow, 1986;Stow, Howell, & Nelson, 1984), although, deformation is usually merely described as a factor of confinement of gravity flow sediments. The seafloor topography, controlled by deformation, evolves through time and may influence the sedimentary gravity currents at both short-term (instantaneous depositional process scale) and long-term (1 -5 My: turbiditic system scale).…”