Biostratigraphy, sedimentology and high resolution sequence stratigraphy of the Mishrif Formation, Dubai
The Middle to Upper Cenomanian Mishrif Formation of Dubai has been interpreted applying biostratigraphic, sedimentologic and sequence stratigraphic concepts. Fourteen wells have been analysed in core and thin-section. These key wells were chosen to cover the geographical extent of the Mishrif and its stratigraphic distribution in offshore Dubai. The identification of thirteen biofacies is based on the trends In composition of microfossil assemblages. Observations on sedimentary features, both in core and thinsection, were also made. Six age significant bioevents are used to constrain stratigraphic boundaries into a chronological framework, and also as bathymetric indicators. Beneath the top of the Middle Cenomanian a MFS (Maximum Flooding Surface) has been recognised. It is possible to correlate this surface at a regional scale. During the Late Cenomanian small intrashelf basins established in the Dubai area, but shallowwater conditions persisted at some localities. Several erosional surfaces were also identified below the base-Laffan unconformity (top MishrifFormation). Local palaeogeography and structure (e.g.: salt diapiric movement) play important roles within the Gulf region. During the Middle to Late Cenomanian the platform was rhythmically affected by exposure and erosion mainly in the north-western part of the Dubai area (structural highs). Intrashelf basins, often characterised by stagnant conditions (anoxia), were developed especially in the south-eastern part of the region. The study is focused on a better understanding of the depositional model of the Mishrif Formation.