| Abstrakt: |
Nigerian gold mineralization has been identified to occur in primary, eluvial and alluvial forms, with around 90% of production coming from the alluvial sources. The Wonaka Schist belt has been recognised to consist of placer gold with mostly erratic and irregular distributions within the river systems. Despites such occurrences, the distribution, sedimentology and provenance of the alluvial sediments in the region are not well studied. This study examined the granulometric attributes, transport history and heavy mineral distribution associated with the placer gold mineralization. These were achieved through field mapping, grain size analysis, binocular microscopy and gold-heavy mineral correlations. Fluvial deposited angular to sub-angular gravel, sand, silt and clay cutting across the metasediments and granitoids make up the stream sediments in the area. These sediments are mainly medium to coarse-grained sand particles, which exhibit well to poor sorting (0.56 -- 2.23) and coarse skewness (0.06 -- 0.46). Environmentally stable minerals including zircon, rutile, tourmaline and garnet are dominant within the heavy mineral concentrates, with varied proportions of mafic silicate minerals indicating immature types, typical of sediments close to the source area. The results of granulometric analyses and the occurrence of mafic silicate minerals indicate immature sediments, transported by low to high energy fluvial system not far from the sediment source. Gold and rutile, which despite having dissimilar specific gravities were found to correlate positively which may be indicative of the occurrence of an orebody, consistent with auriferous mineralization related to deformational and alteration stages of orogenies. [ABSTRACT FROM AUTHOR] |
