THE EFFECT OF CALCAREOUS NANOFOSSILS BIOSTRATIGRAPHY OF WELL X DEEP OFFSHORE EASTERN DAHOMEY BASIN,NIGERIA
CHAPTER 1
INTRODUCTION
GENERAL STATEMENT
Micropaleontology is an important aspect of geology. It involves the study of microfossil. Most sediments contain microfossil, and the kind of microfossil depends largely on the original age, environment of deposition and burial history of the sediment. Because microfossils are small and abundant they can be recorded from small sample. Hence when a geologist wish to know the age of rock or the salinity and depth of water under which it was laid down, it is to microfossil they will turn to for quick and reliable answer. Also geological surveys, deep sea drilling programs, oil and mining companies working with small samples available from borehole cores and drill cutting have all employed micropaleontologists to learn more about the rock they are handling(Cavalier Smith,T.1987).
Biostratigraphy is the grouping of strata into unit based on their fossil content with the aim of zonation and correlation. As such biostratigraphy is concerned primarily with the identification of taxa, tracing their lateral and vertical extent and dividing the geological column into units defined on their fossil content. Microfossils are among the best fossils for biostratigraphical analysis because they are extremely abundant in rock (a particular consideration when dealing with drill cuttings). It should be noted that spore, pollen, diatoms and ostracod are in dispensablefor the biostratigraphy of terrestrial and lacustrine successions, where microfossils can be scarce.
The Eastern Dahomey basin of the Nigeria sector, contains extensive wedge of cretaceous to Recent sediments; up to 3000m which thickens towards the offshore. The basin has been of much geological interest as a result of reported occurrences of bitumen ,limestone, glass sands and phosphates (Nton,2001). The area of study falls within this basin and drill cutting from well X deep offshore is been analyzed for the work.
