ABSTRACT:

The analyses of geometrical properties of wave ripple marks from the Campanian – Early Maastrichtian sandstone units of the Nkporo and Enugu Formations in the Afikpo Sub-basin and the Anambra Basin respectively, have permitted a reconstruction of the ancient oceanographic conditions, epierogenic patterns and paleogeographic history of the basins. The Nkporo Sea in the Afikpo Sub-basin was characterized by low bottom water orbital velocity (47.75 cm/s - 51.42 cm/s) and low wave periods (1.36 – 4.35 s). The minimum and maximum estimated wavelengths vary from 1.46m -1.70m, and 26.05m - 29.44m respectively. The wave heights range from 0.41m – 0.47m while the wave power is from 0.66 kw/m – 0.78 kw/m. The bathymetric estimates for the rippled deposits range from 14.82 – 16.62 m, suggesting shallow water depths for the units. The Campanian Sea of the Anambra Basin had low bottomwater orbital velocity waves (57.17 – 58.41 cm/s) and low to moderate wave periods (1.63 – 5.90 s). Minimum and maximum wavelengths of 2.10 - 2.19 m wavelengths of 50.74 – 54.23 m were estimated for the ancient sea respectively. The wave heights varied from 0.61 – 0.64 m while the wave power varied from 2.04 – 2.32kw/m. The paleowater depth varied from 31.35m – 33.65m.