Sedimentological Aspects of Subcropping Sand Units Within Imo Formation, Western Niger Delta Basin

Abstract

Aquiferous sand units of the Imo Formation have been recently reported to contain warm groundwater around Ofumwengbe community, near Benin City, western Niger Delta Basin, Nigeria. Whereas investigations into the sedimentological aspects of sand members in the Imo Formation outcropping in central and eastern Niger Delta have been documented in literature, reports on the sedimentological aspects of sand members within the Imo formation in the western Niger Delta are either nonexistent or publicly unavailable. This dearth of data provides the impetus for this study, which aims to evaluate the sedimentological aspects of sand members within the Imo formation in the western Niger Delta. Six (06) ditch cutting samples were obtained from the aquiferous section of two (02) warm groundwater wells in the study area. The methodology employed entailed visual lithology characterization using a standard comparator, acid test and granulometry (sieve analysis). The results obtained show that the samples display strong effervescence, and possess dominantly medium grained, leptokurtic, negatively (coarse) skewed, well sorted subangular to subrounded sand sized quartzose framework particles, which have attained submature to mature textural maturity. The aforementioned results when integrated with inferences drawn from binary discriminant plot, models and multivariate statistics indicate a near shore shallow marine paleoenvironment; with fluvial influence was prevalent in this area during the Thanetian age.