[This article belongs to Volume - 55, Issue - 01]
Gongcheng Kexue Yu Jishu/Advanced Engineering Science
Journal ID : AES-25-12-2022-473

Title : Geochemistry and mineralogy of oil shale from Attarat Umm Ghudran area, Jordan
Khalil M. Ibrahim, Hanan Abdel Rahman,

Abstract : Commercial oil shale is widespread in Jordan occurring mostly in the subsurface. More than 20 localities were reported including Attarat Umm Ghudran (AUM) area. Selected oil shale boreholes drilled in the AUM were sampled, analysed and studied in detail. The purpose is to verify their mineralogical composition and geochemical affinities including trace elements content. They were characterized using the polarizing microscopic, X-ray diffraction (XRD), scanning electron microscopy, and X-ray fluorescence spectrometry. Petrographically, the studied oil shale consists of bioclastic mudstone-wackestone, bioclastic packstone and foraminiferal grainstone. The XRD indicates that calcite is the dominant mineral with subordinate quartz. This was emphasized by chemical analysis. The average CaO is 31.03 wt.% followed by SiO2 which makes an average of 16.7 wt.%. The average content of SO3, Al2O3 and P2O5 is 2.69%, 2.25% and 2.1% respectively. Cluster analysis and correlation matrix were calculated for the major and trace element. The cluster analysis subdivided the elements into three group; including a carbonate group, an aluminosilicate group and a phosphate-sulfide group. In general, the studied oil shale is enriched in Zn, Sr, Cr, V, Ni, Zr, Cu, Mn, Rb and U. Uranium attains an average concentration of 21.15 ppm. Chemical composition results were compared with other localities. It was concluded that the enrichment is the result of the euxinic depositional environment, where they would co-precipitate mainly as sulfide minerals. The heavy metals in the oil shale are redox sensitive elements and are related to Mississippi Valley-type deposits.