Paleoenvironmental and paleoclimatic conditions during the deposition of the bauxite layer (Upper Cretaceous) using multi-proxy geochemical and palynological analyses, in the Zabirah Area, Northern Saudi Arabia

Abstract

In this research, Cretaceous claystones in the Az Zabirah area, Northern Saudi Arabia were evaluated to investigate the paleoenvironmental and paleoclimatic conditions during deposition of the claystone sediments. Outcrop samples of claystone from the bauxite zone profile in the Az Zabirah area were analyzed using multi-proxy geochemical and coupled with palynological analysis. Palynological analysis suggested that the age of the Az Zabirah claystones is Maastrichtian of Upper Cretaceous. This evidence is valid due to the presence of microspore taxa Gabonisporis sp. The Az Zabirah claystones have abundant angiosperm taxa, indicating a large terrestrial influx in the interval of the claystone. This finding is confirmed from geochemistry of major and trace elements and mineral compositions. The high concentration of terrestrial detritus oxides, such as SiO2, Al2O3, and TiO2, infers that the Az Zabirah claystones were sourced from terrigenous origin. This is consistent with a significant amount of quartz and kaolinite in the Az Zabirah claystones. The claystones could be deposited under oxic paleo-redox and warm-humid with little aridity climatic conditions. This is indicated by their concentration of the trace element concentrations along with their geochemical ratios. Warm-humid climate condition is also largely supported by the presence of a significant amount of kaolinite.