Paleodepositional environmental diagnosis of the Nsugbe area and environs, Anambra state, southeastern Nigeria: an application of pebble Morphometric studies.

Abstract

The application of pebble morphometric studies in diagnosing the paleodepositional environment of Nsugbe area and environs was carried out using one hundred and seventy (170) vein quartz recovered from seventeen (17) outcrops widely distributed in the studied area. Results show that the pebbles are rounded to subrounded and dominantly compact to compact-bladed. Computed mean values for the flatness index (FI), elongation, maximum projection sphericity index (MPSI) and oblate-prolate index (OPI) are 0.47, 0.74, 0.67 and 0.40 respectively. When these values were integrated with bivariate plots of MPSI versus OPI and mean roundness versus elongation ratio, a dominantly fluviatile depositional environment with subordinate beach/littoral setting are indicated for the Nsugbe area and environs.

KEY WORDS: Pebble morphometry, Paleodepositional environment, Fluviatile, Nsugbe, Anambra basin.