Tectono-Stratigraphic Evolution of the Late Cretaceous-Eocene of Jordan: Implications for the Arabian Plate Active Margin Phase

Summary A revised tectonostratigraphic model for the Ajlun and Belqa Groups (Upper Cretaceous-Eocene) in Jordan has been developed by integrating extensive outcrop and subsurface stratigraphic data. This updated model allows for precise dating of the Azraq-Hamza Graben’s initiation and evolution as Late Turonian to early Campanian in age ( Kalifi et al., 2025 ). The Late Albian-early Turonian displays a gradual north to northwestward thickening trend across Jordan during a phase of tectonic quiescence. In the overlying late Turonian-early Campanian, there is ample evidence for extensional/transtensional tectonic activity, with an acme during the early Campanian, expressed in the development of the northwest-trending Azraq-Hamza Graben in central-east Jordan. This graben, with an offset of c. 1800 m, is part of a regional structural feature, extending southeastwards to the Wadi Sirhan Graben in Saudi Arabia and northwestwards to the Levant Basin. The subsequent late Campanian-Eocene succession records reduced tectonic subsidence within the graben during a sag phase and marks a return to regional stability. This timing aligns the Azraq-Hamza Graben with the large-scale tectonic evaluation of the African-Arabian plate deformation and evolution during the Late Cretaceous active margin phase, which played a critical role in the shaping of the petroleum systems of the region.