Lagging -


  • Lagging -Planks or small timbers placed between steel ribs along the roof of a stope or drift to prevent rocks from falling, rather than to support the main weight of the overlying rocks.
  • Lamprophyre -An igneous rock, com posed of dark minerals, that occurs in dykes; sometimes contains diamonds.
  • Laterite - A residual soil, usually found in tropical countries, out of which the silica has been leached. May form orebodies of iron, nickel, bauxite and manganese.
  • Launder - A chute or trough for conveying pulp, water or powdered ore in a mill.
  • Lava -A general name for the molten rock ejected by volcanoes. Leachable - Extractable by chemical solvents.
  • Leaching - A chemical process for the extraction of valuable minerals from ore; also, a natural process by which ground waters dissolve minerals, thus leaving the rock with a smaller proportion of some of the minerals than it contaitied originally.
  • Lens -Generally used to describe a body of ore that is thick in the middle and tapers towards the ends.
  • Lenticular -A deposit having roughly the form of a double convex lens.
  • Level - The horizontal openings on a working horizon in a mine; it is customary to work mines from a shaft, establishing levels at regular intervals, generally about 50 meters or more apart.
  • Lignite -A soft, low-rank, brownish- black coal.
  • Limestone -A bedded, sedimentary deposit consisting chiefly of calcium carbonate.
  • Limit order -An order made by a client to a broker to buy or sell shares at a specified price or better.
  • Limonite -A brown, hydrous iron oxide.
  • Line cutting - Straight clearings through the bush to permit sightings for geophysical and other surveys.
  • Lode -A mineral deposit in solid rock.
  • Logging - The process of recording geological observations of drill core either on paper or on computer disk.
  • London fix -The twice-daily bidding session held by five dealing companies to set the gold price. There are also daily London fixes to set the prices of other precious metals.
  • London Metals Exchange -A major bid ding market for base metals, which operates daily in London.
  • Long position -Securities owned out right or carried on margin.
  • Long ton -2,240 lbs. avoirdupois (compared with a short ton, which is 2,000 lbs.).