Kinematic Modeling of Subduction, Obduction, and Mountain-Building Geodynamic Processes in Central Oman

In this study, we present new regional, crustal-scale, balanced and restored cross-sections across the central Oman Mountains to refine the structural style and reconstruct the kinematic evolution of subduction-driven obduction and subsequent mountain building since the Albian–Cenomanian boundary. The present-day cross-section constrains footwall ramp locations in both autochthonous and allochthonous domains, allowing estimates of the minimum original lengths of paleogeographic units. It also identifies four major detachment levels that exert key controls on both allochthonous nappe emplacement and autochthonous crustal deformation: (a) the Semail Ophiolite detachment and its metamorphic sole; (b) the Hawasina detachment developed along the syn-rift to post-rift unconformity within the Hawasina Basin; (c) the mid-crustal flat–ramp–flat, thick-skinned thrust beneath Jabal Akhdar at ~15 km depth, likely inherited from Paleozoic orogenic events; and (d) the Early Cambrian Ara Salt detachment at 4–5 km depth in the Fahud foreland basin. Integration of balanced and restored cross-sections with tectono-stratigraphic, tectono-metamorphic, and geochronological constraints allows the definition of three evolutionary stages: (1) a pre-obduction stage (Albian–Cenomanian boundary to 95.2 Ma), characterized by NE-dipping intra-oceanic subduction and slab rollback (events 1–2); (2) an obduction stage (~95.2–80 Ma), marked by emplacement of the Semail Ophiolite and Hawasina nappes onto the Oman margin (events  3–5); and (3) a post-obduction mountain-building stage since Campanian times (event 6). This kinematically constrained reconstruction of the Semail Ophiolite and Hawasina nappes offers a reference framework for interpreting other obduction systems worldwide, particularly along most segments of the Alpine–Himalayan orogenic belt where geological exposure has been overprinted by subsequent continental collision.