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MEETINGS REPORTS 1. “Minerals in National Development”: Nigerian Mining and Geosciences Society: Jos

IGERIA hopes to increase its oil reserves through an intense exploration programme. N with investment encouraged by both indigenous and non-indigenous companies. This announcement came from the Hon. Minister for Petroleum Resources, Prof. J. Aminu, in the opening session of the NMGS 27th Annual Conference held last March in Jos. The Conference attracted some 500. mostly Nigerian. delegates to the two days of technical presentations, during which three parallel sessions were run. A post-Conference field excursion was also held.

Over 80 technical papers were presented, of which ten had a direct bearing on the petroleum geology of Nigeria. with the Cretaceous sedimentary basins being the main focus. Petroleum activities are. of course. concentrated in the Niger Delta, with little or no work being carried out at present in the Cretaceous basins, and researchers are therefore keen to find out whether or not these basins are hydrocarbon-prone.

Utilizing mean random vitrinite reflectance, fluid inclusion trapping temperatures, and illite crystallinity temperatures, S.O. Akande (University of Ilorin) showed that the Albian to Santonian shales in the Abakaliki area were heated to 200 - 240°C. and have therefore been buried to ranks beyond the “oil window”. while the Campano-Maastrichtian shales were still located within the ”window”. The latter interpretation was confirmed by G.I. Unomah and C.M. Ekweozor (University of Ibadan). who concluded that the Campano- Maastrichtian Nkporo Shale has great petroleum potential in the Calabar. Afikpo and Anambra Basins. They placed the “oil window” between 449 and 2.333m. based on an integrated interpretation of data from TOC. Rock-Eva1 pyrolysis. elemental analysis of pre-isolated kerogen. capillary GC, computerized GC, and mass spectrometry analysis. Also dealing with the Campano-Maastrichtian deposits of the Southern Benue Trough, L.C. Amajor (University of Pon Hurcoun) recognized various siliclastic depositional environments from the Nkporo and Enugu shales (prodelta megafacies). the Mamu Formation (delta-front megafacies) and the Ajalli Sandstone (delta-plane megafacies). Based on the stratigraphic position of the Owelli and Afikpo sand-bodies, and the source- rock characteristics of associated shales, it was suggested that the sand-bodies could be hydrocarbon-bearing in the subsurface. The occurrence of tar sands in the Owelli Sandstone was cited as consistent with this interpretation.

The source-rock characteristics of the Eocene Oshosun Formation in the Benin Flank led J.O. ldowu er ul. (Ondo State University) to classify this unit as of low petroleum generation potential. S.J. Coker and E.M. Aduku (University qf Benin) recognized several siliclastic depositional environments within the Cretaceous sedimentary rocks of the Benin Flank. Utilizing the basic principles of hydraulic potential, I.G. Nwankwo ( F n Owerri) showed that the dynamics of groundwater flow systems could constitute a potential tool for petroleum exploration. An understanding of the existing 3-dimensional subsurface flow system and its genesis is of the same importance as a knowledge of the stratigraphy and structure of any sedimentary basin in the search for petroleum.

The technical papers were limited to 20 mins in length. and ended with group discussions on several topics including ”The Impact of the Petroleum Industry on national development in Nigeria”. In conclusion. i t was generally agreed that the organising committee should be congratulated for assembling this interesting and diverse selection of papers and people.

L.C. Amajor University of Port Hareour?. Nigeria