Hard or soft shale; apparently = thill, n.2 dialect.

A miners' term for shale stained dark by vegetable matter. Cf. bat, n.2 11.

Shale interstratified between seams of coal, iron-ore, etc. Cf. bass, n.4

(a) argillaceous shale or aggregate of a bluish colour, used esp. in road-making; (b) copper in the form of a matte (matte, n.2), produced in…

? shale containing fossil scallops.

a dark-coloured, finely laminated carbonaceous shale rich in organic compounds.

laminated shale.

spec. = alum shale n. at alum, n.1 compounds 3. dialect.

a fissile shale, in coalmines, etc.

‘An indurated wavy calcareous shale’ (Phillips) found among limestone rocks. Also attributive, famp-bed.

Applied attributively to a deep brown shale found in Boghead. See torbanite, n.

a black or dark brown shale which contains an insoluble organic deposit (kerogen) from which oil can be obtained by distillation.

shale which readily splits into very thin, paper-like laminae.

Name for a kind of red shale; also attributive. symon fault n. an interruption of a seam of coal by shale or other material (see quots.).

a band of shaly rock occurring in the Wenlock formation in Wales.

A slate-like shale used (often in irregularly-shaped pieces) for paving, flooring, and tiling. Also applied to any similar material. Often used as…