Investigation of Sediment Migration From The Abakaliki Anticlinorium To The Anambra Basin - A Geostatistical Approach

Abstract

The present investigation focused on geochemical evaluation of shale sequences in The Lower Benue Trough using geostatistical approach Thirty two representative samples of shale sequences of The Asu River Group, Nkporo Group and Mamu Formation in The Lower Benue Trough were subjected to Multi-Parameter study in an attempt to present a model of the sediment provenance, and paleoenvironment diagenetic conditions. The X-ray diffraction and Inductively Coupled Plasma Mass spectrometry (ICP-MS) techniques were employed to examine and establish qualitative and quantitative constituents of the Major oxides, Trace and Rare Earth elements. The major minerals determined include SiO2 (40.96%, 56.08% & 60.39%)2, Al2O3 (15.09%, 18.27% and 21.16%), TiO2 (0.75%, 1.73% and 1.63%) and Fe2O3 (9.66%, 2.78% & 2.85%), for Asu River Group, Nkporo Group and Mamu Formation respectively. The studies suggest high influx of sediments into both The Abakaliki Anticlinorium and the Anambra Basin. When tested with multivariate statistical techniques such as Factor, Principal Component, Correspondence and Cluster analyses, the hidden affinities within the sediments were revealed in terms of similarities and dissimilarities. Enrichment and depletion of biogenic indicators CaO (EF=1.87 − 0.01) and P2O5 (EF=1.58 − 0.33) in the studied Asu River Group and Anambra basin sediments indicate deep marine to marginal marine paleoevironment of deposition respectively. Chemical examination of the maturity indexes indicate that the Anambra basin sediments were more matured, indicating that most of the Anambra Basin sediments were reworked from the Abakaliki Anticlinorium.