Abstract
Debris flow deposits of large aerial extent have been detected on the lower continental rise off northwest Africa using GLORIA long-range dual sidescan sonar.
A preliminary interpretation of the sonographs with high-resolution (3.5 kHz) seismic profiles and gravity cores illustrates the potential for spatial mapping of these deposits. The transport directions indicated on the sonographs show that these sediments, emplaced by mass transport, are the downslope continuation of the Saharan Sediment Slide. The distance from an observed “toe” of a debris flow lobe to the most southerly slide scar is of the order of 1,000 km.
Similar content being viewed by others
References
Somers, M. L., and others, 1978. GLORIA-II—An improved long-range side-scan sonar. In: Oceanology International, London, pp. 16–24.
Laughton, A. S., 1982. The first decade of GLORIA. Journal of Geophysical Research, v. 86, pp. 11511–11534.
Kidd, R. B., 1982. Long-range sidescan sonar studies of sediment slides and the effects of slope mass sediment movement on abyssal plain sedimentation. In: S. Saxov and J. K. Nieuwenhuis (eds.), Marine Slides and Other Mass Movements. Plenum Press, New York, pp. 289–303.
Kidd, R. B. and Roberts, D. G., 1982. Long-range sidescan sonar studies of large-scale sedimentary features in the North Atlantic. Geological Society of Aquitaine Bulletin, v. 31, pp. 11–29.
Kidd, R. B., and Searle, R. C., 1983. Sedimentation in the southern Cape Verde Basin: Regional observations by long-range sidescan sonar. In: Stow, D. A. V. and Piper, D. J. W. (eds.), Fine Grained Sediments. Special Publication Geological Society of London, in press.
Stride, A. H., Belderson, R. H., and Kenyon, N. H., 1982. Structural grain, mud volcanoes and other features on the Barbados ridge complex revealed by GLORIA long-range sidescan sonar. Marine Geology, v. 49, pp. 187–196.
Embley, R. W., 1975. Studies of deep sea sedimentation processes using high frequency seismic data. Doctoral thesis, Columbia University, New York, 334 pp.
Embley, R. W., 1976. New evidence for the occurrence of debris flow deposits in the deep sea. Geology, v. 4, pp. 371–374.
Embley, R. W., 1980. The role of mass transport in the distribution and character of deep ocean sediments with special reference to the North Atlantic. Marine Geology, v. 38, pp. 23–50.
Embley, R. W., and Jacobi, R. D., 1977. Distribution and morphology of large submarine sediment slides and slumps on Atlantic continental margins. Marine Geotechnology, v. 2, pp. 205–228.
Damuth, J. E., 1980. Use of high frequency (3.5 kHz-12 kHz) echograms in the study of near-bottom sedimentation processes in the deep sea: A review. Marine Geology, v. 38, pp. 51–75.
Jacobi, R. D., and Hayes, D. E., 1982. Bathymetry, micro-physiography and reflectivity characteristics of the West African margin between Sierra Leone and Mauritania. In: U. Von Rad, K. Hinz, M. Sarnthein, and E. Seibold (eds.), Geology of the Northwest African Continental Margin. Springer-Verlag, Heidelberg, pp. 182–212.
Johnson, M. A., 1970. Physical Processes in Geology. Freeman, Cooper and Co., San Francisco, 571 pp.
Embley, R. W., and Hayes, D. E., 1974. Giant submarine slump south of the Canaries. Geological Society of America Abstracts with Programs, v. 6, pp. 721.
Embley, R. W., 1982. Anatomy of some Atlantic margin sediment slides and some comments on ages and mechanisms. In: S. Saxov and J. K. Neiuwenhuis (eds.), Marine Slides and Other Mass Movements. Plenum Press, New York, pp. 189–214.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Simm, R.W., Kidd, R.B. Submarine debris flow deposits detected by long-range side-scan sonar 1,000-kilometers from source. Geo-Marine Letters 3, 13–16 (1983). https://doi.org/10.1007/BF02463436
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02463436