Underclay definitions

Underclay

• (n.) A stratum of clay lying beneath a coal bed, often containing the roots of coal plants, especially the Stigmaria.
Found on http://thinkexist.com/dictionary/meaning/underclay/

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Underclay

Underclay is a stratum of clay lying beneath a coal bed, often containing the roots of coal plants, especially the Stigmaria.
Found on http://www.probertencyclopaedia.com/browse/HU.HTM

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