PETROGRAPHIC STUDY OF OSO AND ITS ENVIRONS, AFIKPO BASIN, NIGERIA
This Petrographic study was carried out on eleven variously indurated sandstone sample obtained from Oso and environs located in Afikpo Basin, in the South Benne trough, Nigeria. The Area is bound within longitudes 70 471 301E and 70 551 E and latitudes 50 501 N and 50 551 N. The studied areas included the locations in Ndi-Obasi, Oso Edda, Oso-Uduma, Ndu Arusi, Amaso Nta, Ifu Obasi, Ndi Ikpo, Ndi Uche, and Oso Owuta. The rocks in the studied area are highly indurated arkosic Sandstone, siltstone, bioclastic siltstone, and shale from the Cenomanian-Turonian-Santonian formations of the Asu-River Group, Eze Aku Shale and Agwu Shale which has affected by tectonic and magmatic activities during the santonian orogeny. Petrographic, thin section analysis and photomicrographs indicate various initial stages or processes of early metamorphism in arkosic sandstone, siltstone and shale. The rocks are hornfels but with blastopsammitic and blastopelitic relict textures.