combination trap

combination trap

[‚käm·bə′nā·shən ¦trap]
(geology)
Underground reservoir structure closure, deformation, or fault where reservoir rock covers only part of the structure.
References in periodicals archive ?
This combination trap seal blocks out sewer gases, and the covering BlueSeal layer blocks out urine odors from the room, according to Waterless.
There is also evidence that subtle stratigraphic trapping could enhance the size of combination traps.