ABSTRACT

The Turonian shelf edge, which delimited a large carbonate shelf platform, closely corresponds to the present-day shoreline of Israel. A NE-trending shelf basin, over 30 km long and about 5-10 km wide, had been cut into the shelf rocks during the regression which terminated the Cenomanian depositional cycle. The basin sediments include lithoclast calcarenites, oligosteginid calcilutites, mixtures of both and some small hippuritid patch reefs. The contemporaneous platform sediments include dolostones, pellet miliolid limestones and a caprinid fringing reef belt.

The cyclic interbedding of well sorted, frequently cross-bedded lithoclast calcarenites and pelagic oligosteginid calcilutites in the basin points to a sedimentary regime controlled by periodic currents, such as tide or storm induced currents. The clastic carbonate material, forming the calcarenites, had been eroded and was transported from the shelf platform to the basin by these currents. Occasional calcarenite shoals, probably at the outlets of a tidal channel, were favorable sites for patch reef development within the basin.

Differential recrystallization and cementation of the oligosteginid calcilutites is attributed to differences in primary detrital aragonite and clay contents and to proximity to aquiferial rocks. The high aragonite and low clay content of the calcilutites deposited at the basin's margin and their contact with an active aquiferal system resulted in the formation of limestones, whereas the low aragonite and high clay content of the calcilutites deposited in the basin center and their isolation from fresh water circulation resulted in the formation of chalks.