期刊名称:Research Journal of Environmental and Earth Sciences
印刷版ISSN:2041-0484
电子版ISSN:2041-0492
出版年度:2012
卷号:4
期号:2
页码:151-161
出版社:Maxwell Science Publications
摘要:An investigation to identify the suitability of zircon crystals as provenance indicators of the relatively mature sandstones of the Neoproterozoic strata in the Voltaian Basin was conducted. A total of 154 zircon grains were critically studied, all extracted from 14 sandstones samples; 7 from Lower Voltaian Kwahu-Morago Group and 7 from the Middle Voltaian Oti-Pendjari Group. Zircon typology analysis indicates anatectic origin with some contribution of a volcanic material for the Kwahu-Morago Group. Zircons from the Oti-Pendjari Group, however, showed an evolution in the source-area with three probable main sources identified for the sediments. These are; (1) zircon sub-population of crustal origin as one of the sources, (2) zircon sub-population with a strong mantle affinity and towards a more aluminous type. These zircon sub-populations have been interpreted as coming either from the same calc-alkaline source rock; or that it has its origin in two distinct sources, one with calc-alkaline and the other one with a subalkaline origin. The zircon typology study here shows that the Kwahu-Morago Group experienced sediment supply mainly from the Birimian sedimentary basins with some contribution from the volcanic belts. On the other hand sediments from the Oti-Pendjari Group were mostly derived from the calc-alkaline rocks of the Pan-African orogen with minor contribution from the Birimian granitoids. This study clearly showed that zircon typology does not only help establish provenance study but also adds a considerable degree of sophistication.