Elemental Geochemistry and Biomarker Measurements of the Silurian Shale of Qusaiba Formation, Tayma Area, Northwestern Saudi Arabia: Implication for Organic Matter Input and Paleoenvironmental Conditions

This study systematically analyzes the dark shale samples of Silurian Qusaiba Formation from Tayma Quadrangle outcrop section in northwest Saudi Arabia, and assesses source nature its organic matter main sedimentary environmental conditions during accumulation matter. The are characterized by total carbon (TOC) sulfur contents with values range 0.87–1.76 wt. % 0.59–4.64 %, respectively, indicating a marine setting ranging dysoxic to anoxic conditions. biomarkers relatively low Pr/Ph ratio between 0.50 1.24. abundance tricyclic terpanes high C27 C29 regular steranes equated C28 sterane, providing evidence that derived primarily organisms, including algal other aquatic some terrigenous land plants, was deposited under significant oxygen may contribute preservation deposition. inorganic geochemical indications suggest shales were accumulated warm–humid climate salinity stratification water columns.