Cretaceous Sequence Stratigraphy and Depositional Systems of the Arabian Plate; Implications for Global Exploration and Reservoir Description

Simmons, Michael ¹; Davies, Roger ¹; Lodola, Domenico ¹
(1)Neftex Petroleum Consultants Ltd, Abingdon, United Kingdom.

The Cretaceous of the Arabian Plate contains some of the largest petroleum systems on earth. Its stratigraphy represents a transformation from a passive margin to a foreland basin setting, induced by initial compression and subsequent collision associated with the closure of the Neo-Tethyan Ocean. The Berriasian to Early Valanginian succession contains important basin margin packstone-grainstone carbonate ramps characterised by reworked Lithocodium-Bacinella material. Following a regional Late Valanginian unconformity and prior to the prominent early Turonian unconformity, the passive margin setting was subjected by tectonically-induced periods of strong siliciclastic input to platform settings normally prone to carbonate deposition. These established mixed siliciclastic-carbonate deposition over wide areas. Proximal successions are dominated by non-marine to paralic clastics while deeper water prodelta shales separated proximal areas from outboard carbonate platforms. Siliciclastic deposition declined with time, probably due to hinterland denudation, and carbonate platforms re-established themselves across these areas. Carbonate platforms throughout were prone to periodic exposure and incision. They also enclose common intrashelf basin settings that became important sites for source rock deposition. Rudist-bearing facies are a major component of basin margin settings. This variable stratigraphy is ideal for identifying sedimentary responses to eustatic changes in sea level, relationships to global anoxic events and establishing sequence stratigraphic models for mixed siliciclastic-carbonate successions. These models are applicable at exploration and reservoir scales and can be applied to equivalent successions in other regions of the world.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.