Keywords
Field geological
remote sensing
lineament
structural evolution
Abstract
Field Geological and Remote Sensing Studies of Pegmatites Occurrence in Idah Sheet 267, Nigeria was carried out. Field geological mapping revealed thatthe pegmatites in the Ogodo (Ajaokuta) occur as swarms of discrete dykes and ridges.Whereas, those around the Itobe area occur mainly as dykes. The pegmatites intrudes into the basement granites and schist in both the Ogodo (Ajaokuta) and the Itobe. The Mineralogy of pegmatites around the Ogodo (Ajaokuta) area consist of simple to complex mineralogy.The complex mineralogy besides Quartz, Feldspar and Mica also contain well developed crystals of Tourmaline and disseminated Tourmaline. Whereas, the pegmatites in the Itobe area is complex and more diverse in terms of assemblages of gemstones than the pegmatites in Ogodo (Ajaokuta) area.Both Field evidence from joint values and lineament extraction from remote sensing as indicated on rose plot shows a major N-S trends. Shear zone encountered in the study area is an indication of faulting system that may have contributed partly to the emplacement of the pegmatites in the Sheet. Field geological mapping and remote sensing are valuable inproviding a preliminary insight into thestructural evolution of the pegmatites.
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