MINERALOGICAL ANALYSIS

The petrographic and mineralogical analysis of siliciclastic and carbonate facies within the southeastern Dahomey Basin, Nigeria, was studied with the aim of interpreting their provenance, depositional environment, diagenetic evolution, and reservoir potential. Thirty three samples were collected and analyzed. Analysis involved X-ray diffraction (XRD) for mineralogical characterization and thin-section petrography for micro-structural and textural evaluation. Six representative samples were analyzed, comprising three siliciclastic units from depths of 1610– 1870 ft and three carbonate units from 730–930 ft across two wells within the study area. The siliciclastic samples are dominated by quartz, feldspar (orthoclase and albite), and muscovite, indicating derivation from granitic and gneissic sources of the Precambrian Basement Complex. Moderate textural maturity and the presence of albitized feldspars suggest limited reworking and shallow burial diagenesis. The carbonate samples, composed mainly of bioclastic and peloidal packstones to wackestones, reflect shallow-marine to outer shelf depositional settings, influenced by mixed carbonate–siliciclastic sedimentation during transgressive phases. Diagenetic features such as sparry calcite cementation, muscovite preservation, and feldspar albitization point to a multi-stage, low-thermal diagenetic history under closed-system conditions. High quartz content, low clay development, and early marine cementation collectively indicate moderate to good reservoir quality, with porosity largely preserved by mechanical rather than chemical processes. The results of petrography and mineralogy of Siliciclastics and Carbonate facies in Southeastern Dahomey Basin revealed that the units are potential for hydrocarbon-bearing reservoirs.

Five (05) clay samples were obtained from various locations in Uzebba and its environs with the aim of ascertaining its mineralogical and geochemical compositions, qualifying the clay samples and determining its economic potentials. The results obtained showed the predominance of SiO2 (62.23 to 77.48 wt.%), Al2O3 (13.50 to 18.88wt.%), Fe2O3 (0.83 to 13.83 wt.%), TiO2 (2.15 to 3.05 wt.%), CaO (0.20 to 1.05wt.%) with traces of MnO (0.02 to 0.03 wt.%), P2O5 (0.03 to 0.23 wt.%) and K2O(0.87-0.39wt.%), respectively. The mineralogical results showed that quartz was predominant in all the samples (51.00 to 64.00%) followed by Orthoclase (4.20 to 20.00%) and Kaolinite (11.00 to 16.80%). From the results obtained it shows that the Uzebba clay is kaolinitic in nature. The clay minerals found in the study area is suitable for ceramic, glass, paint, paper and refractory bricks production.