Latitudinal variations in submarine channel sedimentation patterns: the role of Coriolis forces
Cossu, R and Wells, MG and Peakall, J, Latitudinal variations in submarine channel sedimentation patterns: the role of Coriolis forces, Journal of the Geological Society, 172, (2) pp. 161-174. ISSN 0016-7649 (2015) [Refereed Article]
Turbidity currents transport clastic sediments from the continental margin to deep ocean basins and along their
pathways they erode large submarine channels. The driving mechanisms for submarine channel evolution are highly complex,
reflected by recent debates about the formation and global distribution of sinuosity in turbidite channels. We present
novel experiments on channelized gravity currents running over an erodible bed, where the magnitude of Coriolis forces is
changed to reproduce conditions at low and high latitudes. We find a striking systematic change in deposition and erosion
patterns as Coriolis forces become dominant at high latitudes so that erosion and deposition occur only on opposite sides of
channels; in contrast, at low latitudes significant inner-bank intra-channel bars form on alternate sides of sinuous channels.
Our observations show very good agreement with sedimentation patterns in Coriolis-dominated contourite drift systems and
with deposits in modern and ancient turbidity current channels. We hypothesize that Coriolis forces are a key parameter for
submarine channel evolution and sedimentary architecture at high latitudes but not at low latitudes; this proposal offers a new
approach to interpret deep-sea architectural features at high latitudes.
density and turbidity currents, submarine channels