IJSRP, Volume 5, Issue 7, July 2015 Edition [ISSN 2250-3153]
Ibrahim M.M.M, Ibrahim S.I, Elhag A.M.H and Dafalla M.S
Heavy mineral assemblage of sediments in Almanaqil Ridge, Gezira State, Sudan has been studied, to identify, and if possible, to know their source and transporting agent. Four sediment samples were analyzed for determinations heavy mineral assemblage. The separation of these minerals was carried out using bromoform (specific gravity 2.85). These were followed by slide examination under the petrographic microscope. Heavy minerals grains of soil samples collected from outside the study area (sample 1 and 2) were compared with those inside the study area (sample 6 and 7). The heavy minerals assemblages of Zircon, Tourmaline, Rutile, Silimatate, Andalusite , Garnet, Epidote, and Quartz indicated its derivation from mixed sources of acid igneous rock to medium and high grade metamorphic rocks. The calculated % ZTR (Zircon, Tourmaline, Rutile) values varied between 47.99% to 26.08 % in in the samples from outside the study area compared with values of those inside study area which varied between 12.92% to 17.95 % and the mean ZTR percentage indices was 37.035 % of outside the study area and 15.5% of those inside study area. The three most abundant were Quartz, Garnet and Andalusite with values 50.33 %, 34.2 % and 24.52, respectively. Heavy minerals assemblages in the sediments of study area and that outside the area indicated low Zircon Tourmaline Rutile indices. This index is used as a clue for the identification of the source and as measure of the maturity of the sediments. The low ZTR index might indicate mineralogical immaturity and mineralogical composition. Heavy sand mineralogy revealed that the origin of the sand in the area was the Nubian sandstone.