Skip to main content

The Laurentian Fan: Sohm abyssal plain

Abstract

The 0.5- to 2-km thick Quaternary Laurentian Fan is built over Tertiary and Mesozoic sediments that rest on oceanic crust. Two 400-km long fan valleys, with asymmetric levees up to 700-m high, lead to an equally long, sandy, lobate basin plain (northern Sohm Abyssal Plain). The muddy distal Sohm Abyssal Plain is a further 400-km long. The sediment supplied to the fan is glacial in origin, and in part results from seismically triggered slumping on the upper continental slope. Sandy turbidity currents, such as the 1929 Grand Banks earthquake event, probably erode the fan-valley floors; but thick muddy turbidity currents build up the high levees.

This is a preview of subscription content, access via your institution.

References

  1. Uchupi, E., and Austin, J., 1979. The stratigraphy and structure of the Laurentian cone region. Canadian Journal of Earth Sciences, v. 16, pp. 1726–1752.

    Article  Google Scholar 

  2. Parsons, M. G., 1975. The geology of the Laurentian Fan and the Scotian Rise. Canadian Society of Petroleum Geologists Memoir, no. 4, pp. 115–167.

    Google Scholar 

  3. Prest, V. K., and Grant, D. R., 1969. Retreat of the last ice sheet from the Maritime Provinces of Canada. Geological Survey of Canada Paper 69-33, pp. 1–15.

  4. Stow, D. A. V., 1981. Laurentian Fan: morphology, sediments, processes and growth pattern. American Association of Petroleum Geologists Bulletin, v. 65, pp. 375–393.

    Google Scholar 

  5. Doxsee, W. W., 1948. The Grand Banks Earthquake of November 18, 1929. Publications of the Dominion Observatory, Canada, v. 7, pp. 323–336.

    Google Scholar 

  6. Piper, D. J. W., and Normark, W. R., 1982. Effects of the 1929 Grand Banks earthquake on the continental slope off eastern Canada. Geological Survey of Canada Paper, v. 82-1B, pp. 147–151.

    Google Scholar 

  7. Horn, D. R., and others, 1971. Turbidites of the Hatteras and Sohm Abyssal Plains, western North Atlantic. Marine Geology, v. 11, pp. 287–323.

    Article  Google Scholar 

  8. Vilks, G., Buckley, D. E., and Keigwin, L., submitted. Quaternary sedimentation on the southern Sohm Abyssal Plain. Sedimentology.

  9. Hacquebard, P. A., Buckley, D. E., and Vilks, G., 1981. The importance of detrital particles of coal in tracing the provenance of sedimentary rocks. Bulletin des Centres de Recherches Exploration Production Elf-Aquitaine, v. 5, pp. 555–572.

    Google Scholar 

  10. Edgar, D. C., and Piper, D. J. W., 1979. A new bathymetric map of the middle Laurentian Fan. Maritime Sediments, v. 15, pp. 1–3.

    Google Scholar 

  11. Institute of Oceanographic Sciences. 1979. Cruise report Discovery 119.

  12. Piper, D. J. W., and Normark, W. R., 1982. Acoustic interpretation of Quaternary sedimentation and erosion on the channelled upper Laurentian Fan, Atlantic Margin of Canada. Canadian Journal of Earth Sciences, v. 19, pp. 1974–1984.

    Article  Google Scholar 

  13. Normark, W. R., Piper, D. J. W., and Stow, D. A. V., 1983. Quaternary development of channels, levees and lobes of the middle Laurentian Fan. American Association of Petroleum Geologists Bulletin, v. 67, pp. 1400–1409.

    Google Scholar 

  14. Fruth, L. S., 1965. The 1929 Grand Banks turbidite and the sediments of the Sohm Abyssal Plain. Unpublished M.Sc. thesis, Columbia University, New York.

    Google Scholar 

  15. Buckley, D. E., 1981. Geological investigation of a selected area of the Sohm Abyssal Plain, Western Atlantic: CSS Hudson cruise 80-016. Atomic Energy of Canada Ltd., Technical Report 168.

  16. Buckley, D. E., 1982. Canadian report to Site Selection Task Group 1981. In: D. R. Anderson (ed.), Proceedings of Seventh International NEA/Seabed Working Group Meeting, La Jolla, California, March 15–19, 1982. Sandia National Laboratory, SAND 82-0460, pp. 69–73.

  17. Jacobi, R. D., in preparation. Echo character of the Laurentian Fan.

  18. Wang, Y., Piper, D. J. W., and Vilks, G., 1982. Surface texture of turbidite sand grains, Laurentian Fan and Sohm Abyssal Plain. Sedimentology, v. 29, pp. 727–736.

    Article  Google Scholar 

  19. Basham, P. W., and Adams, J., 1982. Earthquake hazards to offshore development on the eastern Canadian continental shelves. Proceedings of the 2nd Canadian Conference on Marine Geotechnical Engineering.

  20. Stow, D. A. V., and Bowen, A. J., 1980. A physical model for the transport and sorting of fine-grained sediment by turbidity currents. Sedimentology, v. 27, pp. 31–46.

    Article  Google Scholar 

  21. GEBCO, 1982. General Bathymetric Chart of the Oceans. 1∶10,000000. Sheet 5.08. 5th edition. Canadian Hydrographic Service.

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Piper, D.J.W., Stow, D.A.V. & Normark, W.R. The Laurentian Fan: Sohm abyssal plain. Geo-Marine Letters 3, 141–146 (1983). https://doi.org/10.1007/BF02462459

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02462459

Keywords

  • Debris Flow
  • Turbidite
  • Continental Slope
  • Turbidity Current
  • Abyssal Plain