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Rock Dredges from Blake Escarpment Near Great Abaco Canyon

1969; American Association of Petroleum Geologists; Volume: 53; Linguagem: Inglês

10.1306/5d25c975-16c1-11d7-8645000102c1865d

1558-9153

Robert E. Sheridan, Jim Smith, J. M. Gardner,

Geological formations and processes

Lower Cretaceous (Neocomian-Albian) shallow-water algal and foraminiferal limestones were recovered from the base of the Blake escarpment in water depths of 4,200-4,780 m. Tertiary (Pliocene and Paleocene) pelagic foraminiferal calcilutites were dredged from the upper lip (1,470-1,620 m) of the escarpment and canyon, where the Tertiary section appears to be only 150 m thick. Fossil and stratigraphic correlations imply that a Neocomian-Aptian algal-reef formation was once continuous between Great Abaco Canyon and the Blake nose and that this platform has subsided as much as 4,500 m. This net subsidence appears similar to that found for Andros Island in the Bahamas, but is not comparable in detail to that in the Blake nose area. The latter difference may be explained by pos ible faulting between the canyon and the nose.