Stratigraphy and rifting history of the Mesozoic-Cenozoic Anza rift, Kenya
- Marathon Oil Co., Littleton, CO (United States)
- Marathon Oil Co., Houston, TX (United States)
Lithological and compositional relationships, thicknesses, and palynological data from drilling cuttings from five wells in the Anza rift, Kenya, indicate active rifting during the Late Cretaceous and Eocene-Oligocene. The earlier rifting possibly started in the Santonian-Coniacian, primarily occurred in the Campanian, and probably extended into the Maastrichtian. Anza rift sedimentation was in lacustrine, lacustrine-deltaic, fluvial, and flood-basin environments. Inferred synrift intervals in wells are shalier, thicker, more compositionally immature, and more poorly sorted than Lower Cretaceous ( )-lower Upper Cretaceous and upper Oligocene( )-Miocene interrift deposits. Synrift sandstone is mostly feldspathic or arkosic wacke. Sandstone deposited in the Anza basin during nonrift periods is mostly quartz arenite, and is coarser and has a high proportion of probable fluvial deposits relative to other facies. Volcanic debris is absent in sedimentary strata older than Pliocene-Holocene, although small Cretaceous intrusions are present in the basin. Cretaceous sandstone is cemented in places by laumontite, possibly recording Campanian extension. Early Cretaceous history of the Anza basin is poorly known because of the limited strata sampled; Jurassic units were not reached. Cretaceous rifting in the Anza basin was synchronous with rifting in Sudan and with the breakup and separation of South America and Africa; these events likely were related. Eocene-Oligocene extension in the Anza basin reflects different stresses. The transition from active rifting to passive subsidence in the Anza basin at the end of the Neogene, in turn, records a reconfigured response of east African plates to stresses and is correlated with formation of the East Africa rift.
- OSTI ID:
- 5594528
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 77:11; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
Similar Records
Geologic evolution and aspects of the petroleum geology of the northern East China Sea shelf basin
Cenozoic Tectono-stratigraphic sequences of the Shelf Rift Basin, East China Sea
Related Subjects
KENYA
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
EXPLORATION
LITHOLOGY
CENOZOIC ERA
GEOLOGIC FAULTS
MESOZOIC ERA
RIFT ZONES
TECTONICS
AFRICA
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
MINERAL RESOURCES
PETROLOGY
RESOURCES
020200* - Petroleum- Reserves
Geology
& Exploration