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The location of the India-Arabia plate boundary prior to the formation of the Sheba ridge in the Gulf of Aden is a matter of debate. A seismic dataset crossing the Owen Fracture Zone, the Owen Basin, and the Oman Margin was acquired to track the past locations of the India-Arabia plate boundary. We highlight the composite age of the Owen Basin basement, made of Paleocene oceanic crust drilled on its eastern part, and composed of pre-Maastrichtian continental and oceanic crust overlaid by ophiolites emplaced in Early Paleocene on its western side. A major fossil transform fault system crossing the Owen Basin juxtaposed these two slivers of lithosphere of different ages, and controlled the uplift of marginal ridges along the Oman Margin. This transform system deactivated ∼40 Myrs ago, coeval with the onset of ultra-slow spreading at the Carlsberg Ridge. The transform boundary then jumped to the edge of the present-day Owen Ridge during the Late Eocene-Oligocene period, before seafloor spreading began at the Sheba Ridge. This migration of the plate boundary involved the transfer of a part of the Indian oceanic lithosphere formed at the Carlsberg Ridge to Arabia. This Late Eocene-Oligocene tectonic episode at the India-Arabia plate boundary is synchronous with a global plate reorganization event corresponding to geological events at the Zagros and Himalaya belts. The Owen Ridge uplifted later, in Late Miocene times, and is unrelated to any major migration of the India-Arabia boundary. [ABSTRACT FROM AUTHOR]

• The Late Cretaceous India-Africa Transform plate boundary is identified at Chain Ridge. • The Paleogene India-Africa transform plate boundary is identified at the Chain Fracture Zone and within the Owen Basin. • The Masirah ophiolites emplaced along a transform boundary. • The oceanic lithosphere subducting nowadays beneath Makran derives from the East Somali Basin instead of Neotethys. The Arabian Sea in the NW Indian Ocean is a place where two major transform boundaries are currently active: the Owen Fracture Zone between India and Arabia and the Owen Transform between India and Somalia. These transform systems result from the fragmentation of the India-Africa Transform boundary, which initiated about 90 Myrs ago, when the India-Seychelles block separated from Madagascar to move towards Eurasia. Therefore, the geological record of the Arabian Sea makes it possible to investigate the sensitivity of a transform system to several major geodynamic changes. Here we focus on the evolution of the India-Africa transform system during the ~47–90 Ma interval. We identify the Late Cretaceous (~90–65 Ma) transform plate boundary along Chain Ridge, in the North Somali Basin. From 65 to ~42–47 Ma, the India-Africa transform is identified at the Chain Fracture Zone, which crossed both the Owen Basin and the North East Oman margin. Finally, the transform system jumped to its present-day location in the vicinity of the Owen Ridge. These shifts of the India-Africa boundary with time provide a consistent paleogeographic framework for the emplacement of the Masirah Ophiolitic Belt, which constitutes a case of ophiolite emplaced along a transform boundary. The successive locations of the India-Africa boundary further highlight the origin of the Owen Basin lithosphere incoming into the Makran subduction zone. [ABSTRACT FROM AUTHOR]