Morphodynamics of supercritical turbidity currents in the channel-lobe transition zone

Postma, George; Hoyal, David C.; Abreu, Vitor; Cartigny, Matthieu J.B.; Demko, Timothy; Fedele, Juan J.; Kleverlaan, Kick; Pederson, Keriann H.. 2016 Morphodynamics of supercritical turbidity currents in the channel-lobe transition zone. In: Lamarche, Geoffroy; Mountjoy, Joshu; Bull, Suzanne; Hubble, Tom; Krastel, Sebastian; Lane, Emily; Micallef, Aaron; Moscardelli, Lorena; Mueller, Christof; Pecher, Ingo; Woelz, Susanne, (eds.) Submarine Mass Movements and their Consequences: 7th International Symposium. Cham, Switzerland, Springer International Publishing, 469-478, 621pp. (Advances in Natural and Technological Hazards Research, 41).

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Abstract/Summary

This study aims to resolve process-facies links at both bed and environmental scales for the channel lobe transition zone (CLTZ). Data comes from existing experimental and modern CLTZ studies and from new outcrop studies. The experiments show that the CLTZ architecture of supercritical turbidity currents is complex and different from their counterparts where flows are subcritical throughout. Supercritical CLTZ’s are characterised by erosive channels formed by supercritical turbidity currents, by offset stacked lobes deposited from subcritical turbidity currents and by hydraulic jump related mouth bar deposits and upslope onlapping backfill deposits at the down slope end of the transition zone. Erosive channels and backfill features can be resolved by high resolution seismic data, yet evidence for supercritical flow must come from facies analysis of core data. Outcrop examples of the CLTZ from the Tabernas submarine fan (SE Spain) and the Llorenç del Munt deep-water delta slope (N. Spain) are used to establish such links between seismic scale architecture and facies recognised in cores. The outcrops described here were mapped as transition zone, and show 100 m sized, spoon-shaped scours filled with sediment containing sandy to gravelly backsets up to 4 m in height. Their facies and architecture is indicative of deposition by hydraulic jumps, can be recognized from cores, and is a good proxy for further predicting CLTZ architecture constructed by supercritical turbidity currents.

Item Type:	Publication - Book Section
Digital Object Identifier (DOI):	10.1007/978-3-319-20979-1_47
ISBN:	9783319209784
ISSN:	1878-9897
Additional Keywords:	CLTZ; Super-critical turbidity currents; Submarine fan; Backset; Flutes
Date made live:	13 Oct 2016 15:36 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/514826

Item Type:

Publication - Book Section

Digital Object Identifier (DOI):

10.1007/978-3-319-20979-1_47

ISBN:

9783319209784

ISSN:

1878-9897

Additional Keywords:

CLTZ; Super-critical turbidity currents; Submarine fan; Backset; Flutes

Date made live:

13 Oct 2016 15:36 +0 (UTC)