| 释义 |
underclay
underclay (ˈʌndəˌkleɪ) n (Geological Science) a grey or whitish clay rock containing fossilized plant roots and occurring beneath coal seams. When used as a refractory, it is known as fireclayunderclay
underclay[′ən·dər‚klā] (geology) A layer of clay or other fine-grained detrital material underlying a coal bed or comprising the floor of a coal seam. Also known as coal clay; root clay; seat clay; seat earth; thill; underearth; warrant. |