Abstract
Understanding the thermal maturation of these source rocks is fundamental for evaluating hydrocarbon generation, migration, and accumulation processes, as well as for reducing exploration uncertainty in both mature and frontier areas of the basin. This study presents an integrated assessment of the maturation history of the principal source rocks within the Sirt Basin through the interpretation of geological, geochemical, and basin modeling datasets. The analysis combines source rock characteristics, burial history, geothermal evolution, and thermal maturity indicators to reconstruct the timing and spatial distribution of hydrocarbon generation across the basin. Thermal maturity evaluation is based on multiple parameters, including vitrinite reflectance (Ro), Rock-Eval pyrolysis (Tmax), Hydrogen Index (HI), Production Index (PI), and Total Organic Carbon (TOC), together with one-dimensional and two-dimensional basin modeling calibrated using measured subsurface data. The results indicate that source rock maturation varies significantly across the basin due to differences in burial depth, structural evolution, sedimentation rates, and regional heat flow. The deepest depocenters exhibit mature to overmature conditions, where organic matter has reached peak oil generation and, locally, wet gas generation stages. In contrast, structurally elevated regions and basin margins generally remain within the immature to early mature stages, limiting their hydrocarbon generation potential. The maturation history reflects the complex tectono-sedimentary evolution of the Sirt Basin, where episodes of rapid subsidence during the Late Cretaceous and Paleocene promoted increased burial and accelerated thermal evolution. Variations in heat flow associated with regional rifting further influenced the onset and extent of hydrocarbon generation. Basin modeling suggests that the principal phase of oil generation occurred after significant burial during the middle to late Cretaceous time, with continued maturation in deeper basin sectors These temporal relationships correspond closely with the timing of hydrocarbon migration and trap formation, supporting the effectiveness of the basin's petroleum systems. The integrated maturation framework developed in this study enhances the understanding of hydrocarbon generation patterns within the Sirt Basin and provides valuable constraints for petroleum system analysis, exploration risk assessment, and future resource evaluation. The findings contribute to improved prediction of mature source kitchens, migration pathways, and prospective exploration targets, offering a robust geological basis for optimizing exploration strategies in one of Libya's most important hydrocarbon-producing basins.