The extensive karstic system found today in Cretaceous carbonates in central and northern Israel has been developing since Late Turonian times. Initial Late Turonian karstic activity is evidenced by small sand-filled solution cavities within the upper Turonian sequence. Senonian palaeodolines are found in central and northern Israel but are missing from the southern Negev and Sinai areas. This is attributed to the emergence of northern Israel during the lowermost Senonian (Coniacian stage), while southern Israel was submerged. The palaeodolines take the form of circular to irregular depressions (a few tens of meters in diameter) cut into Turonian and/or Santonian rocks. In many of these palaeodolines, the Turonian bedrock dips concentrically towards the center of the depression — a feature characteristic of dolines resulting from the collapse of bedrock into underlying conduits. Most of the palaeodolines are filled with collapsed beds of Turonian limestones and marine chalks of Senonian (mostly Campanian) age. Marine sediments of Eocene and Miocene age are locally found as doline fill, overlying the Senonian chalks, indicating repeated phases of emergence and karstic erosion in Late Coniacian, post-Santonian—pre-Campanian, pre-Middle Eocene, and pre-Late Miocene times, followed by submergence and marine deposition. Pockets of dolomite crystal sands are found in some Senonian dolines. Their δ 18O ranges between −1% and −2.3% and δ 13C between + 0.8% o and +1.8% o PDB. It is suggested that these dolomites were formed at the seawater-freshwater inferface during one of the later transgressive phases between the karstic stages. The Senonian palaeodolines are cut only into (horizontally bedded) strata of Late Turonian age, showing only moderate development of paleokarst at this time. Considerable uplifting of this region and the entailing incision of erosional canyons prior to the Late Miocene (Tortonian) marine transgression, created favorable conditions for a very developed karstic phase.