The Dead Sea Rift (Fig. 1), which evolved during

Buoyancy-driven flow associated with salinity variations is proposed as the principal driving force that has caused large-scale migration of brine and hydrocarbons at the Dead Sea Rift. Numerical simulations indicate the coexistence of two basin-scale groundwater flow systems, one atop the other, with opposite flow directions. The first is a density-driven migration of brine through deep aquifers from the rift outward, which has affected hydrocarbon maturation and migration, and the formation of three small gas fields. The second is a topography-driven groundwater flow through relatively shallow aquifers from the surrounding highlands toward the rift valley, which has caused oil biodegradation, forming heavy oils and asphalts. Simulations indicate that flow-field configurations of both groundwater and hydrocarbons have changed during the structural evolution of the rift, illustrating the interrelationships between basin formation, paleohydrology and hydrocarbon reservoir formation