Sequence architecture and carbonate platform configuration (Late Cenomanian–Santonian), Sinai, Egypt



Abstract Relative sea-level changes on the mixed carbonate–siliciclastic platform of Sinai are manifested in shifts of distinct facies belts (deep-water facies, high-energy subtidal, shallow subtidal, lagoon, shallow shoreface siliciclastics, supratidal) and are interpreted in terms of sequence stratigraphy. Eight sedimentary sequences are recognized for the Upper Cenomanian to Santonian. Their correlation along a north–south transect reveals distinct changes in lithofacies and progradation/retrogradation patterns within the individual systems tracts. The number and stratigraphy of the sequence boundaries of Sinai correlate well with those from adjacent areas. Patterns of increased subsidence are documented for the Central Sinai Basin since the Late Cenomanian by increased thickness of the stratal packages (post-CeSin 7 HST, post-TuSin 1 LST and HST, post-TuSin 2 LST) and are balanced by varying accumulation rates. Based on new sedimentological and biostratigraphic data, large-scale palaeogeographic maps and cross-sections show the: (1) temporal and spatial evolution of the Central Sinai Basin, e.g. its latest Cenomanian initial formation, Lower Turonian deep-water facies, Middle Turonian to Coniacian synsedimentary subsidence; (2) drowning of the Cenomanian platform coinciding with the latest Cenomanian to Early Turonian relative sea-level rise; (3) re-establishment of the platform in Middle–Late Turonian times; and (4) a Coniacian basin and swell morphology.