unconformity trap A stratigraphic trap formed by folding, uplift, and erosion of porous strata, followed by the deposition of later beds which can act as a seal for oil, gas, or water. Although common structures, these traps contain only 4% of the world's oil, perhaps because of losses that occur during uplift and erosion. See NATURAL GAS; PETROLEUM; and POROSITY. Compare ANTICLINAL TRAP; FAULT TRAP; REEF TRAP; STRATIGRAPHIC TRAP; and STRUCTURAL TRAP.

unconformity trap A stratigraphic trap formed by the folding, uplift, and erosion of porous strata, followed by the deposition of later beds which can act as a seal for oil, gas or water. Although common structures, these traps contain only 4 per cent of the world's oil, perhaps because of losses that occur during uplift and erosion.