The Lower and Middle Cretaceous rock record of the eastern Arabian Plate – stratigraphic architecture and global events

The Lower and Middle Cretaceous rocks of the eastern Arabian Plate consist dominantly of carbonates, with thinner intervals of marls, sandstones and organic-rich deposits. They were deposited during major climatic and tectonic events, of which several of global impact, and thus provide a unique insight in the Cretaceous geological history. In addition, these rocks host a significant proportion of the world’s hydrocarbon reserves and are potential reservoirs for CO2 sequestration.

In this presentation a synthesis of the depositional history of the Lower and Middle Cretaceous of the eastern Arabian Plate will be presented based on integrated outcrop and subsurface datasets which were collected over approximately 70 years of geological research carried out by academia and industry.

It will demonstrate how sequence stratigraphy has been a fundamental integrating methodology to produce predictive geological models with respect to the distribution of reservoir, seal and source rock facies. In addition, the detailed study and age dating of these rocks has also helped to identify several global events, such as (a) the Oceanic Anoxic Events (OAE’s 1a and 2), short periods of worldwide accumulation of organic-rich deposits, which were most likely caused by massive volcanic eruption events, (b) short term, high magnitude (up to 80m) sea level falls and rises, that caused exposure of carbonate platforms and fluvial river incisions and turbidite fan deposition, which were most likely caused by short ice-cap growth and melting events, and (c) faunal and floral extinctions, caused by these environmental and climatic changes.