As an example of an epeiric carbonate ramp depositional system, the worldclass outcrops of the Middle Jurassic Dhruma Formation were studied in the Oman Mountains (Sultanate of Oman). An integrated approach was followed: facies analyses were combined with quantitative sequence-stratigraphic methods as well as bio- and chemostratigraphy. Depositional environments range from peritidal to lagoonal and ‘shoal-like’ environments. A conspicuous four-level hierarchy of cyclicity was identified. This is substantiated by facies trends and specific cycle indicators such as various types of discontinuity surfaces, biofacies changes, and a suite of quantitative- and semi-quantitative sequencestratigraphic methods like facies stacking pattern plots, facies percentage, bedthickness and bio-component diversity plots, as well as diagrams representing the environmental range and facies belt width per high-frequency sequence. Potential reservoir facies are present in the form of peloidal and oolitic grainstones; potential baffle/seal facies as vastly extensive mudstones and marls. A transition from peritidal to low-energy lagoonal deposits to increasingly highenergy deposits can be observed towards the top of the Dhruma Formation representing a landward shift of the depositional environment. This study may be useful as outcrop analogue for the hydrocarbon-bearing parts of the Dhruma in the subsurface of the Arabian Plate and for similar epeiric carbonates elsewhere.
As an example of an epeiric carbonate ramp depositional system, the worldclass outcrops of the Middle Jurassic Dhruma Formation were studied in the Oman Mountains (Sultanate of Oman). An integrated approach was followed: facies analyses were combined with quantitative sequence-stratigraphic method...
مادة فرعية
The International Association of Sedimentologists
