Abstract
The Silurian hot shale of the Ghadames Basin is one of the most prolific Paleozoic source rocks in North Africa and represents the principal contributor to the region's conventional hydrocarbon accumulations. This study evaluates its geochemical characteristics and hydrocarbon generation potential through an integrated analysis of organic geochemistry and thermal maturity data. Source rock quality was assessed using total organic carbon (TOC), Rock-Eval pyrolysis, hydrogen index (HI), oxygen index (OI), production index (PI), and kerogen typing, complemented by biomarker and stable carbon isotope analyses to determine organic matter origin, depositional environment, and thermal evolution. The results indicate that the hot shale contains predominantly marine organic matter composed of Type II kerogen, with localized Type II/III mixtures reflecting minor terrestrial input. Organic-rich intervals exhibit excellent source rock quality, characterized by high TOC values and elevated remaining hydrocarbon generation potential. Biomarker distributions indicate deposition under predominantly anoxic to dysoxic marine conditions during the post-glacial Silurian transgression, which favored exceptional preservation of organic matter. Thermal maturity parameters demonstrate a regional increase in maturity toward the basin depocenters, where the source rock has reached the peak to late oil window and locally entered the wet gas generation stage. Geochemical data further suggest that the Silurian hot shale possesses high oil-proneness and favorable expulsion efficiency, making it the dominant source of Paleozoic petroleum systems in the basin. The integration of geochemical parameters provides a comprehensive understanding of source rock quality, maturity, and hydrocarbon generation potential. These findings improve the regional characterization of the Ghadames Basin petroleum system and provide valuable constraints for petroleum system modeling, exploration risk assessment, and the evaluation of both conventional and unconventional hydrocarbon resources across North Africa.