Stratigraphic aspects of the Upper Jurassic to Lower Cretaceous of Saudi Arabia

The Upper Jurassic to Lower Cretaceous, Oxfordian to Valanginian, lithostratigraphic succession of Saudi Arabia is divided into the Jurassic Shaqra Group and the Cretaceous Thamama Group, the boundary of which lies within the uppermost Tithonian. This interval includes at least five third-order sequence boundaries and maximum flooding zones. J60 and K40 are two regionally recognized sequence boundaries, and J50 and J100 represent two regionally established Jurassic maximum flooding surfaces. The Upper Jurassic succession includes shallow- to deep-marine carbonates of the Hanifa (Oxfordian) and Jubaila (Kimmeridgian) formations, and shallow-marine carbonates and evaporites of the Arab (Kimmeridgian) and Hith (Kimmeridgian to Tithonian) formations. The Upper Jurassic to Lower Cretaceous succession includes the shallow to moderately deep carbonates of the Sulaiy Formation (Tithonian to Berriasian) with the overlying Yamama Formation being of Cretaceous age (Valanginian). These formations were deposited in a period of increasing global temperature, during a transitional phase leading to greenhouse.