The redefined Hamrat Duru Group represents continental rise sediments derived from a Triassic to Lower Cretaceous (Cenomanian), northeast-facing, passive carbonate margin at the edge of the Arabian platform. The sequence was later emplaced, together with the Semail ophiolite, onto the margin during a Cenomanian - Maastrichtian compressional event. This thesis traces the evolution of this group, to identify the sedimentological, tectonic and climatic parameters that controlled deposition. ?Lower Triassic spreading initiated the development of the Hawasina Ocean, the segment of Neo-Tethys in which the Hamrat Duru Group was deposited, such that by the Land inian/Carnian, two basins existed. These were the margin-proximal Al Ayn basin, and the Duru basin that was floored by oceanic crust. These were separated by a rifted basement horst. Triassic sedimentation (Zulla Formation) was controlled by platform hinterland uplift that fed terrigenous sands into the basin and reduced carbonate production and input, thereby raising the CCD. A subsequent reduction of sand input resulted in the deposition of cherts and silicified limestones, which was followed by a return to limestone deposition after carbonate production had resumed along a narrow shelf edge. Lower Jurassic subsidence and platform break-up was accompanied by increased carbonate production. Initially, localised quartz input either mixed with platform sediments or by-passed them to form deeper water quartz sand bodies (Guweyza Sandstone Formation). By the Middle Jurassic, ooid shoals were widely developed, feeding the Guweyza Limestone Formation.

The redefined Hamrat Duru Group represents continental rise sediments derived from a Triassic to Lower Cretaceous (Cenomanian), northeast-facing, passive carbonate margin at the edge of the Arabian platform. The sequence was later emplaced, together with the Semail ophiolite, onto the margin dur...