| Author(s) | Omar A. Al-Harbi and M. Mujtaba Khan |
| Affiliation | Natural Resources & Environment Research Institute, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia P. O. Box 6086 Riyadh 11442, Saudi Arabia |
| Title | Mineralogy and Geochemistry of Unayzah Formation, Central Saudi Arabia: Implications for Provenance Interpretation |
| Source | Journal of King Saud University. Science. Volume 18, No 1. (2006/1426) |
| Abstract | The Unayzah Formation (Permian-Carboniferous), a thick sedimentary succession of clastic unit deposited after the Hercynian orogeny in central Saudi Arabia. Transgression and regression as a result of eustatic change deposited these sediments. Unayzah formation consists of sandstone and shale. The provenance of the formation has been identified by petrographic and geochemical methods. On the basis of petrography, the formation can be divided into a feldspar-free lower unit, and a feldspar-bearing upper unit. The petrographic data suggest that the sediments are derived from craton interior (82.5%) and are of recycled origin (17.5%). However, the data mainly supports intense reworking during the course of deposition rather than recycling; chemical weathering in the source area and postdepositional change (diagenesis) are responsible for mature quartzarenite. The geochemistry of sandstone and shale indicate that the tectonic settings of the study areas were passive margin and polycyclic continental fields. Finally, the petrographic, chemical and paleocurrent data indicate that the probable provenance of the sediments were the Arabian Shield to the west, and some other sources. |
