Geochemical Comparison of Crude Oil Along South Atlantic Margins
C.F. Schiefelbein, J.E. Zumberge, N.C. Cameron, S.W. Brown, 2000. "Geochemical Comparison of Crude Oil Along South Atlantic Margins", Petroleum Systems of South Atlantic Margins, Marcio Rocha Mello, Barry J. Katz
Download citation file:
The continental margin basins of Brazil and west Africa share very similar tectonostratigraphic units because of their proximity in Late Jurassic–Early Cretaceous time. As a result of the paleogeographic ties between the South American and the African plates, the oil habitat of the marginal basins of both continents can often be correlated. To better understand the petroleum systems along the South Atlantic margins, geochemical results obtained from the analysis of 290 oils from the major Brazilian and west African coastal basins were statistically evaluated to establish genetic relationships, distinguish source paleoenvironments and age, and identify different petroleum systems. A number of general oil families composed of genetically related oils were identified, several of which contain oils from both sides of the margin. Areas where oils of mixed provenance occur are also identified.
Presalt (Neocomian–Aptian) lacustrine oils can be separated into at least three distinct families and are present in the Congo, Lower Congo, and Benguela Basins of west Africa and the Recôncavo, Campos, Potiguar, Ceará, and Bahia Sul Basins of Brazil. Genetically related oils may be present in the Campos Basin and offshore central Angola and in the Recôncavo Basin and central Gabon and northern Angola.
Postsalt (Upper Cretaceous–Tertiary) marine oils are present in the Ivory Coast and the northern Gabon, Lower Congo, Kwanza, and Benguela Basins of west Africa and the Santos, Espírito Santo, and Sergipe–Alagoas Basins of Brazil. Oil mixing may have occurred in the Ivory Coast, Lower Congo, and Kwanza. Genetically related oils may occur in the Sergipe–Alagoas Basin and from northern Gabon. Oils from Nigeria, Benin, Equatorial Guinea, Cameroon, offshore northern Angola, and the Foz do Amazonas Basin of northern Brazil originated from Tertiary source rocks primarily composed of terrigenous organic matter deposited in fluvial deltaic or nearshore marine environments.
Figures & Tables
Petroleum Systems of South Atlantic Margins
“Giant oil and gas fields have been discovered through recent exploration in the deep and ultra-deep water regions of Angola, Brazil, and Nigeria. This volume includes 1. Descriptions of the petroleum geology of more than 12 basins along the two margins 2. Discussion of various components of the petroleum systems within these basins 3. Discussion on the use of the petroleum systems concept in the South Atlantic marginal basins to classify and characterize the diversity of the systems 4. Methodologies used in the assessment of petroleum system components 5. Overviews of the different components of the region's petroleum systems. Petroleum explorationists and researchers working in the South Atlantic will welcome this addition to their libraries.
The printed version of Memoir 73 was the Winner of the 2000 Dott Award for best AAPG Special Publication.”