wayboardとは 意味・読み方・使い方

名詞

wayboard (複数形 wayboards)

1. (geology, mining) A thin layer or band of rock that separates or defines the boundaries of thicker strata.
   • 1905, Institution of Mining and Metallurgy (Great Britain), Transactions of the Institution of Mining & Metallurgy^[1], volume 15, page 176:

     In the Mill Close Mine, a very rich and extensive flat occurred under a way-board which was topped with a tiny coal seam 1 in. thick or so, the way-board itself being from 1 to 3 ft. thick, and looking very much like an […]