Palynological and lithological results have been employed in interpreting the depositional environment of strata penetrated by the Igbomotoru-1 well at the interval 1123–3583 metres. The environment of deposition is largely transitional with marine influence occurring only at the base of the studied sequence. Zonocostites ramonae is frequent to abundant in most samples: this indicates a high influence of mangrove swamp vegetation in the environment at the time of deposition. The absence or rarity of this species at some horizons within the studied interval is taken as evidence of deposition in a more continental environment or of a swamp forest area composed of non-Rhizophora type trees. The nature of the organic matter points to a source area near the basin of deposition for the sediments.
- Received August 1, 1991.
- Accepted October 1, 1991.
- © 1992 The Micropalaeontological Society