Geol. Also in L. form lithomarga. [ad. mod.L. lithomarga, f. Gr. λίθο-ς stone + L. marga marl.] ‘An early name for several kinds of soft clay-like minerals, including kaolin’ (A. H. Chester, 1896).
1753. Chambers, Cycl. Supp., Lithomarga.
1784. Kirwan, Min., 74. Lithomarga or stone marl.
1815. W. Phillips, Outl. Min. & Geol. (1818), 138. A Quartzose rock … composed of quartz, schorl, beryl and lithomarga.
1820. R. Jameson, Min., II. 74. There are two kinds, viz. Friable Lithomarge, and Indurated Lithomarge.
1843. Portlock, Geol., 210. Lithomarge of greenish-white colour … at Dunluce.
1870. Athenæum, 14 May, 646/3. The one, Restormelite, is a variety of kaolinite, standing nearest to the lithomarge group.
