TY - JOUR
T1 - Sea floor bedforms and their influence on slope accommodation (2019)
AU - Maselli, V
AU - Kneller, B
AU - Taiwo, O. L.
AU - Iacopini, D
N1 - We sincerely thank Petroleum Geo-Services (PGS) Investigação Petrolífera Limitada, and specifically David Hajovsky and Scott Opdyke, that kindly provided the dataset and allowed us to show these results. We would also like to thank Schlumberger for providing academic licenses of their software (Petrel). We are grateful to Associate Editor Kei Ogata for his support, and we sincerely thank reviewers Daniele Casalbore and Kamaldeen Omosanya for their comments and suggestions that significantly improved the quality of the manuscript.
PY - 2019/4
Y1 - 2019/4
N2 - In deep-water settings, the accommodation for sediment transported by turbidity flows relates to the difference between the elevation of the depositional surface and its equilibrium profile. As a consequence, accommodation creation, or disruption, may depend from changes in the physiography of the receiving basin, or changes in the flow properties. In topographically complex slopes, such where salt-withdrawal intra-slope basins occur, three different types of accommodation have been recognized. Among other parameters, the ratio between flow thickness and depth of the intra-slope basin controls the partial, or full, ponding of the sediment in suspension, and consequently, the lithology distribution within the deposit. On a smaller spatial scale, the behavior of bottom-hugging sediment-laden flows can be affected by topographic variations of the sea floor associated with the presence of km-scale bedforms. In this work, we show that ponded lobes accumulate on the convex-up stoss side of pre-existing large-wavelength bedforms (length up to 103, and height up to 102), and that their lithology distribution depends on the flow characteristics respect to the bedform height. In detail, when partial ponding of turbidity currents occurs, flow stripping promotes the accumulation of the coarse-grained fractions on the stoss side of the bedform, while the fine-grained cloud over-spills the lee side, affecting deposition basinward. By introducing the concept of stoss-side accommodation, this work suggests a new mechanism for the formation of ponded coarse-grained facies in slope settings due to the trapping effect large-wavelength bedforms with convex-up stoss sides.
AB - In deep-water settings, the accommodation for sediment transported by turbidity flows relates to the difference between the elevation of the depositional surface and its equilibrium profile. As a consequence, accommodation creation, or disruption, may depend from changes in the physiography of the receiving basin, or changes in the flow properties. In topographically complex slopes, such where salt-withdrawal intra-slope basins occur, three different types of accommodation have been recognized. Among other parameters, the ratio between flow thickness and depth of the intra-slope basin controls the partial, or full, ponding of the sediment in suspension, and consequently, the lithology distribution within the deposit. On a smaller spatial scale, the behavior of bottom-hugging sediment-laden flows can be affected by topographic variations of the sea floor associated with the presence of km-scale bedforms. In this work, we show that ponded lobes accumulate on the convex-up stoss side of pre-existing large-wavelength bedforms (length up to 103, and height up to 102), and that their lithology distribution depends on the flow characteristics respect to the bedform height. In detail, when partial ponding of turbidity currents occurs, flow stripping promotes the accumulation of the coarse-grained fractions on the stoss side of the bedform, while the fine-grained cloud over-spills the lee side, affecting deposition basinward. By introducing the concept of stoss-side accommodation, this work suggests a new mechanism for the formation of ponded coarse-grained facies in slope settings due to the trapping effect large-wavelength bedforms with convex-up stoss sides.
KW - Stoss-side accommodation
KW - ponded lobes
KW - turbidity currents
KW - bedforms
KW - Offshore Brazil
KW - Turbidity currents
KW - Bedforms
KW - Ponded lobes
KW - SEISMIC GEOMORPHOLOGY
KW - SUBMARINE CANYONS
KW - MASS-TRANSPORT
KW - TURBIDITY CURRENTS
KW - FAN
KW - CHANNEL
KW - HIGH-RESOLUTION
KW - ARCHITECTURE
KW - SEDIMENT WAVES
KW - MONTEREY CANYON
UR - https://www.sciencedirect.com/science/article/pii/S0264817219300248
UR - http://www.scopus.com/inward/record.url?scp=85060523316&partnerID=8YFLogxK
UR - http://www.mendeley.com/research/sea-floor-bedforms-influence-slope-accommodation
U2 - 10.1016/j.marpetgeo.2019.01.021
DO - 10.1016/j.marpetgeo.2019.01.021
M3 - Article
VL - 102
SP - 625
EP - 637
JO - Marine and Petroleum Geology
JF - Marine and Petroleum Geology
SN - 0264-8172
ER -