Petrographic Characterization of Selected Sidewall Core Samples from NG-1 Well, Niger Delta, Nigeria: Palaeoclimatic Implication

Abstract

Petrographic investigation of sandstones from Agbada Formation in NG-1 well was undertaken in order to petrographically characterize the sandstones. Petrographic examination of the sandstone shows that the sandstones are mineralogically mature and poorly to moderately sorted quartz arenite. Compositionally, made up of monocrystalline quartz (90-96%), polycrystalline quartz (7-2%), feldspar (2-5%), rock fragments < 3%, silica, hematite cement and clay matrix. Abundant of monocrystalline quartz with marginal undulose extinction over polycrystalline quartz suggest igneous source derivatives. Presence of close packing, point and concavoconvex contacts, weathered plagioclase feldspar, grain dissolution, and fabric imprints indicates intermediate diagenesis. Consideration of petrographic attributes and paleoclimatic discrimination plot inferred semi-humid to humid palaeoclimates.

A Preliminary Study of Groundwater Conditions in a Transitional Environment of Niger Delta using Direct – Current Soundings

“…The study area is underlain by the Benin Formation comprising Miocene to Recent sediments consisting unconsolidated, poorly cemented sands with alternating silt and clay [8]. The sandy sequence is generally poorly sorted and consists of fine to coarse grained [9]. The Benin Formation, which gradually grades into the Quaternary sediments of the Sombreiro-Warri deposits form the aquifers.…”