Deltas of the Lake Malawi rift, east Africa: Seismic expression and exploration implications

Journal Article · Wed Nov 01 04:00:00 EST 1995 · AAPG Bulletin

OSTI ID:161839

Scholz, C A ^[1]

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1. Univ. of Miami, FL (United States)

High-resolution, air-gun-sourced seismic reflection surveys over the offshore regions of five river deltas in Lake Malawi in the East African rift system reveal considerable variability in acoustic facies and stratigraphic architecture. This variability can largely be attributed to the influences of different structural settings, and to a lesser degree to high-amplitude (100-400 m) and high-frequency (1000 to 100,000 yr) fluctuations in lake level. Deltas on flexural and axial margins in the rift lake show well-developed progradational geometries. In contrast, a delta on a steep, accommodation zone margin distributes coarse sediments over a broad depositional apron, rather than concentrating sediment in discrete progradational lobes as on the other deltas. A large border fault margin river delta displays the most complex tectonic and stratigraphic architecture of all the deltas studied. It contains several delta-associated facies, including prograding clinoform packages, fan deltas stacked against a boundary fault, and extensive subaqueous fans. Flexural margin lowstand deltas may be the most prospective for hydrocarbon exploration due to their large, internally well-organized, progradational lobes and their close proximity to deep-water, high total organic carbon lacustrine source facies.

• OSTI ID: 161839
• Journal Information: AAPG Bulletin, Journal Name: AAPG Bulletin Journal Issue: 11 Vol. 79; ISSN 0149-1423; ISSN AABUD2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
AFRICA
ALLUVIAL DEPOSITS
EXPLORATION
OFFSHORE SITES
PETROLEUM
RIFT ZONES
SEISMIC SURVEYS