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Selected composited samples from Lewumeji (0-111m) and Idogun (0- 54m) wells, from Abeokuta Group, Eastern Dahomey Basin, Nigeria, were subjected to detailed lithologic and palynological studies. The studies aimed at determining the lithological sequence, relative age, palynological zone and paleoenvironments of deposition. The core samples were subjected to lithological description and palynological analysis using standard procedure in order to determine palynomorphs contents such as pollen, spore and dinoflagellates. The lithologies from both wells consist of reddish to brown clay, reddish to brown colour, rounded to sub rounded sandstone, dark grey shale denoting possibly fluvial, brackish, lagoonal and marine environments. A total of 31 well preserved low to moderate diverse palynomorphs were recovered from the studied area. The palynomorphs frequency percentage distribution shows that both wells have a higher ratio of land-derived pollen and spores to the marine dinoflagellates; (75%, 25% and 61%, 39%) for Lewumeji and Idogun wells respectively. The microfloral assemblages include abundant Cyathidites sp., Cyathidites minor, Tubistephanocolpites cylindricus, Proteacidites sp., Trilete spore, Foveotriletes margaritae, Monocolpites marginatus, Monoporites annulatus, Pteris sp, Distaverrusporites simplex and Laevigatosporites sp. The dinoflagellates recovered were characterized by the likes of Leiosphaeridia sp., Senegalinium sp., Oligosphaeridinium sp., Paleocytodinium sp., Cerodinium sp. and Subtilisphaera sp. The wells fall within Cyathidites Minor zone, characterized by the diagnostic occurrence of Cyathidites minor, Cyathidites sp. and Monocolpites marginatus dated Upper Maastrichtian to early Paleocene. Paleoenvironmental interpretations based on the abundance of freshwater swamps pollen and Spores, diagnostic dinoflagellates cyst and the Palynomorphs Marine Index (PMI) are suggestive of environmental settings that vary from continental to brackish water and shallow marine.
Jones HA, Hockey RD. The geology of part of Southwestern Nigeria. Geological Survey of Nigeria Bulletin. 1964;31:101.
Fayose EA. Stratigraphic paleontology of Afowo well 1 South Western Nigeria.Geological Survey of Nigeria. 1970;5:65-68.
Adeigbe OC, Ola-Buraimo AO, Moronhunkola AO. Palynology and biostratigraphy of Emi–1 well, Moroh field deep offshore, Eastern Dahomey Basin, Southwestern, Nigeria. International Journal of Scientific and Technology Research. 2013;2(1):58-70.
Whiteman AJ, Nigeria, its petroleum Geology of Nigeria, resources and potential Graham and Trotman, London. 1982;2:223-230.
Kingston DR, Dishroon CP, Williams PA. Global basin classification system. American. Assoc. of petroleum Geologists. Bulletin. 1983;67:2175-2193.
Agagu OK. Geological guide to bituminous sediment in South Western Nigeria. (Unpublished monograph), Department of Geology, University of Ibadan, Ibadan. 1985;3:17.
Omatsola ME, Adegoke OS. Tectonic evolution and cretaceous stratigraphy of the Dahomey Basin. Nigeria. Journal of Mining and Geology. 1981;18(01):130–137.
Salami MB. Petrography and palynology of upper Maastrichtian Abeokuta formation of south- western Nigeria, Nigerian journal of Science. 1987;21:140-146.
Obaje SO, Okosun EA. Paleoenvironmental interpretation of Tomboy field, Offshore western Niger delta, Nigeria. International Journal of Science and Technology. 2013;2(9):628-638.
Adeigbe OC, Amodu OI. Palyno-environmental study of the Araromi -1 well, Eastern Dahomey Basin, Southwest Nigeria. Journal of Science Research. 2015;14.
[ISSN: 1119 7333]
Coker JL, Ejedawe JE. Dynamic interpretation of organic matter maturation and evolution of the oil generative window. AAPG Bulletin. 1983;68(8):1024-1028.
Biliman HG. Offshore stratigraphy and paleontology of the dahomey (Benin) Embayment, West Africa. NAPE BULL. 1992;7(2):121-130.
Enu EI. Nature and occurrence of Tar sands in Nigeria in: Ako BD, Enu EI. (eds). Occurrence, utilization and economic of Nigerian tar sands: 1st worship on Nigerian tar sands, NMGS published Ibadan Chapter, Ibadan, Nigeria.1990;11-16.
Germeraad JH, Hopping CA, Muller JA. Palynology of tertiary sediments from tropical areas. Rev. Paleobot. Palynology. 1968;6:189-348.
Lawal O, Moullade M. Palynological biostratigraphy of the cretaceous sediments in the Upper Benue Basin, N.E. Nigeria. Revue micropaleontologie. 1987;29(1):61-83.
Awad MZ. Stratigraphic, palynological and palaeoecological studies in the East-Central Sudan (Khartoum and Kosti Basins), Late Jurassic to Mid- Tertiary. Berliner geowiss Abh; 1994.
Ola-Buraimo AO. Lithostratigraphy and palynostratigraphy of tuma-1 well, Bornu Basin, Northeastern Nigeria. J. Biol. Chem. Res. 2012;29(2):206- 223.
Ayinla HA, Adeigbe OC, Ola-Buraimo OA, Bankole SA, Adebowale M. Palynostratigraphy and high resolution paleo environmental reconstruction of part of Kemar-1 well, Bornu Basin, northeastern Nigeria. The Pacific Journal of Science and Technology. 2014;15(1): 392–403.
Durugbo EU, Aroyewun RF. Palynology and paleoenvironments of the upper araromi Formation, Dahomey Basin, Nigeria. Asian Journal of Earth Sciences. 2012;5(2):50-62.
Helenes J, Guerra C, Vasquez J. Palynology and chronostratigraphy of the upper cretaceous in the subsurface of Barinas area, Western Venezuela. AAPG Bull. 1998;82(7):1308-1328.
Chukwuma- Orji JN, Okosun EA, Ekom JC, Abolarin JF. A palynology and paleoenvironment of a section from the Amansiodo -1 well, Anambra basin south eastern Nigeria. Journals. Agh.Edu.Pl/Geol. 2017;43(4):293-301.