Recent Sedimentary Processes in the Cap de Creus Canyon Head and Adjacent Continental Shelf, NE Spain: Evidence from Multibeam Bathymetry, Sub-Bottom Profiles and Coring

  1. Michael Z. Li7,
  2. Christopher R. Sherwood8 and
  3. Philip R. Hill9
  1. A. García-García1,2,
  2. T. Schoolmeester3,
  3. D. Orange1,2,
  4. A. Calafat4,
  5. J. Fabres3,
  6. E. Grossman5,
  7. M. Field5,
  8. T.D. Lorenson5,
  9. M. Levey2 and
  10. M. Sansoucy6

Published Online: 3 JAN 2013

DOI: 10.1002/9781118311172.ch4

Sediments, Morphology and Sedimentary Processes on Continental Shelves: Advances in Technologies, Research, and Applications

Sediments, Morphology and Sedimentary Processes on Continental Shelves: Advances in Technologies, Research, and Applications

How to Cite

García-García, A., Schoolmeester, T., Orange, D., Calafat, A., Fabres, J., Grossman, E., Field, M., Lorenson, T.D., Levey, M. and Sansoucy, M. (2012) Recent Sedimentary Processes in the Cap de Creus Canyon Head and Adjacent Continental Shelf, NE Spain: Evidence from Multibeam Bathymetry, Sub-Bottom Profiles and Coring, in Sediments, Morphology and Sedimentary Processes on Continental Shelves: Advances in Technologies, Research, and Applications (eds M. Z. Li, C. R. Sherwood and P. R. Hill), John Wiley & Sons, Ltd, Chichester, West Sussex, UK. doi: 10.1002/9781118311172.ch4

Editor Information

  1. 7

    Geological Survey of Canada (Atlantic), Natural Resources Canada, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, B2Y 4A2 Canada

  2. 8

    U. S. Geological Survey, Woods Hole, MA 02543-1598 USA

  3. 9

    Natural Resources Canada, Sidney, BC, Canada V8L 4B2

Author Information

  1. 1

    Department of Earth and Planetary Sciences, UCSC, Santa Cruz, CA, 95064, USA

  2. 2

    AOA Geophysics Inc., Moss Landing, CA 94039, USA

  3. 3

    UNEP/GRID-Arendal, Teaterplassen 3, N-4836 Arendal, Norway

  4. 4

    GRC Geociències Marines, Universitat de Barcelona, C/Martí Franqués s/n, 08028 Barcelona, Spain

  5. 5

    USGS PACIFIC COASTAL AND MARINE SCIENCE CENTER, 400 Natural Bridges Drive, Santa Cruz, CA 95060, USA

  6. 6

    Laval University, Québec, G1Y 2P1, Canada

Publication History

  1. Published Online: 3 JAN 2013
  2. Published Print: 26 JAN 2012

ISBN Information

Print ISBN: 9781444350821

Online ISBN: 9781118311172

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Keywords:

  • high-resolution multibeam;
  • echo-character;
  • recent processes;
  • shallow gas;
  • continental shelf;
  • submarine canyons;
  • Cap de Creus;
  • Gulf of Lions

Summary

High-resolution seafloor bathymetry and shallow sub-bottom profile data reveal a range of geomorphic expressions in the Cap de Creus canyon head and its adjacent continental shelf, which can be tied to processes of deposition and erosion. A complete suite of geophysical and acoustic data and large set of cores (piston, kasten and box cores) were acquired during different surveys between 2004 and 2005.

The acoustic and seismic data provide a detailed image of the present seafloor and subsurface. We have identified and correlated a total of 13 acoustic facies, tying these to seafloor samples obtained by coring. The integration of the seafloor, shallow subsurface, and core data assist in defining the processes responsible for each of the acoustic facies. The analysis of headspace gas in the core samples indicates a few local sources of anomalous methane. Morphologically, the north and south walls of the canyon are very different. The north wall of the canyon is incised by numerous large amphitheatre-shaped slump scars draped by recent sediment accumulation, and it shows relatively low backscatter. Outcrops, positive relief features, are relatively rare and isolated. The south wall is characterized mostly by erosive processes and relatively high backscatter.

Our interpretation shows a presently erosive and active canyon with a wide range of processes shaping the present-day seafloor. The depositional processes are mostly located in the shallow area with a sandier seabed on the continental shelf and siltier sediment near the head of the canyon. We have interpreted a field of wavy seafloor and a 20 m thick progradational bedform on the continental shelf. Inside the head of the canyon, chaotic facies, furrows, sharp and hyperbolic echoes cover the seafloor indicating how widespread the erosive processes are in the region. The controlling factors for the depositional and erosional environments of the area are discussed and linked with the geophysical datasets.