Fields of multi-kilometer scale sub-circular depressions in the Carnegie Ridge sedimentary blanket: Effect of underwater carbonate dissolution? - Archive ouverte HAL Access content directly
Journal Articles Marine Geology Year : 2005

Fields of multi-kilometer scale sub-circular depressions in the Carnegie Ridge sedimentary blanket: Effect of underwater carbonate dissolution?

François Michaud
  • Function : Author
Anne Chabert
  • Function : Author
Jean-Yves Collot
  • Function : Author
Valentí Sallarès
Ernst R. Flueh
  • Function : Author
Philippe Charvis
David Graindorge
  • Function : Author
  • PersonId : 857428
Joerg Bialas
  • Function : Author

Abstract

Offshore Ecuador, the Carnegie Ridge is a volcanic ridge with a carbonate sediment drape. During the SALIERI Cruise, multibeam bathymetry was collected across Carnegie Ridge with the Simrad EM120 of the R/V SONNE. The most conspicuous features discovered on the Carnegie Ridge are fields of circular closed depressions widely distributed along the mid-slope of the northern and southern flanks of the ridge between 1500 and 2600 m water depth. These circular depressions are 1–4 km wide and typically 100–400 m deep. Most are flat floored and some are so densely packed that they form a honeycomb pattern. The depressions were carved into the ridge sedimentary blanket, which consists of carbonate sediment and has been dated from upper Miocene to upper Pleistocene. Several hypotheses including pockmark origin, sediment creeping, paleo-topography of the volcanic basement, effects of subbottom currents, and both marine and subaerial karstic origins are discussed. We believe that underwater dissolution process merits the most serious consideration regarding the origin of the closed depression

Dates and versions

hal-00112873 , version 1 (10-11-2006)

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François Michaud, Anne Chabert, Jean-Yves Collot, Valentí Sallarès, Ernst R. Flueh, et al.. Fields of multi-kilometer scale sub-circular depressions in the Carnegie Ridge sedimentary blanket: Effect of underwater carbonate dissolution?. Marine Geology, 2005, 216 (4), pp.205-219. ⟨10.1016/j.margeo.2005.01.003⟩. ⟨hal-00112873⟩
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