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：2011
卷号：3
期号：2
页码：95-102
出版社：Maxwell Science Publications
摘要：The aim of this study is to determine the geochemical and mineralogical composition of Bima Sandstone deposite of northeastern Nigeria. A total number of sixteen (16) sandstone samples were collected in Yola area inorder to classify the deposit of the Bima Sandstone exposed in this area on the basis of its chemical and mineralogical make-up. All the samples were selected randomly and subjected to both geochemical and petrographic studies. Relative concentration of the major oxide groups such as silica and alumina alkali oxides, iron oxide and magnesia has been used to classify the deposit. The results of the log of ratio of the m ajor oxide groups indicate that Bima Sandstone of the study area can be classified as greywackes, arkoses and lithic arenites including sub-greywackes and protoquartzites. The abundant alkali values as shown by the relatively high log K2O/Na2O ratio in most of the samples indicated immature sandstones whereas low alkali values in sam ples F, H and M revealed mature sandstones. The enrichment of silica (quartz) over Al2O3 (log SiO2/Al2O3<1.5) indicate that Bima Sandstone has undergone long period of transportation and have been subjected to intense weathering resulting in the destruction of other minerals especially plagioclase and potassium feldspars during transportation. Microscopic examination of about sixteen slides (16) of Bima Sandstone under both plane and cross polars revealed the following average mineralogical composition: quartz (65%) feldspars (14%), mica (9%), iron oxide (5%), calcite (3%) further confirms quartz/lithic arenites and greywackes as some of the predominant sedimentary rocks in the study area.
关键词：Bima Sandstone ; geochemical ; Nigeria ; Northeast ; petrographic ; Yola area
