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1. (Geological Science) a layer of rock that overlies a salt dome and consists of limestone, gypsum, etc
2. (Geological Science) a layer of relatively impervious rock overlying an oil- or gas-bearing rock
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
a mass of anhydrite, gypsum, or limestone immediately above the salt of a salt dome.
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