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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 63 (1979)

Issue: 3. (March)

First Page: 503

Last Page: 503

Title: Calcareous Nannoplankton in Upper Aptian and Albian Black Shales from South Atlantic (DSDP Legs 36, 40)--Sedimentologic Implications: ABSTRACT

Author(s): Denise G. Noel, Helene Manivit

Article Type: Meeting abstract


Nannofacies analyses of 65 samples of Upper Aptian and Albian black shales from the Falkland Plateau, the Cape Basin, and the continental margin off Angola (South Atlantic, DSDP Leg 36, sites 327 to 330; DSDP Leg 40, sites 361 to 364) provide data on depositional environment. The presence of nannoplankton shows undeniable marine conditions, productivity of surface waters, and oceanic connections. The mode of fossilization (coccolith aggregates interpreted as coccospheres dislocated on the spot) indicates stagnant and confined depositional conditions, which are confirmed by the presence of pyrite framboids. Coccoliths that are present only as casts show that dissolution processes took place in the sediment and not in the water column.

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Copyright 1997 American Association of Petroleum Geologists