a. A general term for a soft, spongy, and porous deposit of impure hydrous iron
oxides formed in bogs, marshes, swamps, peat mosses, and shallow lakes by
precipitation from iron-bearing waters and by the oxidizing action of algae,
iron bacteria, or the atmosphere; a bog ore composed principally of limonite
that is commonly impregnated with plant debris, clay, and clastic material. It
is a poor-quality iron ore, in tubular, pisolitic, nodular, concretionary, or
thinly layered bodies, or in irregular aggregates, in level sandy soils, and
esp. abundant in the glaciated northern regions of North America and Europe
(Scandinavia). Syn: limnite;
morass ore; meadow ore; marsh
ore; lake ore; swamp ore.
CF: goethite
b. A term commonly applied to a loose,
porous, earthy form of "limonite" occurring in wet ground. Syn:
bog ore
Source:
Dictionary of Mining, Mineral, and Related Terms