the world > the earth > structure of the earth > constituent materials > rock > sedimentary rock > [noun] > chalk or limestone (3)
? Lime. (Traces of this sense after the Old English period are very uncertain; quot. 1572 is doubtful.)
(a) = chalk, n. (dialect). †(b) Lime. Obsolete. (c) ? Calc spar. (d) Barytes, or heavy spar: see cawk, n.1
calcareous earth = lime, chalk; calcareous spar = calc-spar, n.; calcareous tufa = calc-tuff, n.