The sedimentary response to early Miocene fault reactivation and marginal uplift in the Gulf of Suez is strikingly evident within the Gemsa half-graben. This mid-Rudeis event occurred in the late Burdigalian (16.5 Ma) approximately 8 m.y. after the onset of rifting. In outcrop, complicated lateral facies transitions reflect the change from a ramped margin to a structurally controlled depositional environment. Angular unconformities and truncation mark this event atop marginal tilt-block crests. Distal downlapping sequences are present in adjacent topographic lows that acted as sand depocenters. Channels draining the rift margins acted as point sources for basinward alluvial-fan development. Sand-ratio isopach maps reveal the presence of four active upper Rudeis Formation fan systems within the Gemsa half-graben.