BIOSTRATIGRAPHIC STUDIES OF GA-E WELL, NORTHERN DEPOBELT, NIGER DELTA, NIGERIA

ABSTRACT

A total of twenty-four (24) ditch cutting samples gotten from GA-E Well were provided for the sedimentological and palynological analysis between interval of 9185 ft to 12440 ft with the aim of carrying out a detailed palynomorph biostratigraphic analysis of the well. The sedimentological analysis with sample description yielded lithologies that are shaly sand, sandy shale and shale. . The index minerals include quartz and carbonates. The sediments were treated in the laboratory to concentrate the palynomorphs and promote their microscopic observation. The sediments recovered from the sediment of the GA-E Well in the Niger Delta Basin were assigned age of Late Eocene based on the cooccurrence of different stratigraphic markers such as Monocolpites sp., Psilatricolporites crassus, Retibrevitricolporites obodoensis and pteridophytic spores which include , Laevigatosporites sp., Acrostichum aureum, Verrucatosporites sp. and Polypodiaceoisporites sp. Palynological zonation of the well was based on both the first and last downhole occurrence of the chronostratigraphically significant species. These sediments have been broadly assigned the P480 and P490 palynological zones. The palynofloral analysis of the different sediments yielded a rich recovery of the palynomorphs which were mainly dominated by Laevigatosporites sp., Verrucatosporites sp. and Polypodiaceoisporites sp. The dominance occurrence of pollen and spores species such as Monocolpites sp., Psilatricolporites crassus, Retibrevitricolporites obodoensis and pteridophytic spores which include Verrucatosporites sp. Acrostichum aureum, Laevigatosporites sp., and Polypodiaceoisporites sp, suggests that the studied well was deposited in a predominantly Continental environment.