cap rock(redirected from cap rocks)
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Related to cap rocks: source rocks
cap rock[′kap ‚räk]
An overlying, generally impervious layer or stratum of rock that overlies an oil- or gas-bearing rock.
Barren vein matter, or a pinch in a vein, supposed to overlie ore.
A hard layer of rock, usually sandstone, a short distance above a coal seam.
An impervious body of anhydrite and gypsum in a salt dome.