Journal of Petroleum Geology, Vol.4,
No.1, pp.3-34, 1981
©Copyright 2000 Scientific Press,
Ltd.
POROSITY MODELS AND OIL
EXPLORATION OF AMAPÁ CARBONATES, PALEOGENE, FOZ DO AMAZONAS
BASIN, OFFSHORE NW BRAZIL
Albert V. Carozzi*
*Professor of Geology, University
of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA and
International Oil Exploration Consultant.
Abstract
The extensive thick Paleogene carbonate
platform (Amapa Formation) of the Foz do Amazonas Basin probably
the largest coralgal-foraminiferal platform of the geological
record developed through four depositional cycles expressing
global eustatic changes of sea level. It shows five environmental
belts: slope apron coralgal platform large foraminifer shoal
finger coral bank and restricted lagoon all of which associate
bioaccumulated and bioclastic microfacies. At all times a
terrigenous environment consisting of fan deltas and lagoonal
fine-grained clastics existed immediately behind the carbonate
platform and was connected with the open ocean by transverse
troughs filled with shales and carbonate olistoliths. This
combination of clastic and carbonate environments is unique in
the geological record and today only the Belize Shelf displays
comparable conditions.
