A fine-grained clay used in cleansing wool (esp. formerly; cf. full, v.2 1) and as an adsorbent material and filler. Also: (Geology) a stratum…

= fuller's earth, n. 1.

= fuller's earth, n. 1.

(a) U.S. the first terrace above the normal flood plain of a stream; (b) Australian a second stratum of gold-bearing material found by sinking below…

a hard, impermeable substratum of soil cemented together by iron oxides; (also) the material of such a layer; cf. pan, n.1 7b, hardpan, n. 1.

Mining. A stratum of metal-bearing rock; also, a quartz-vein.

A gold-bearing stratum of bluish gravelly clay. Chiefly as the name (more fully Great Blue Lead) of a particular lode in California.

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

a porous rock stratum, typically of sandstone or unconsolidated sand, impregnated with oil.

(see quot.)

(see quot.)

(see quot.).