BUREAU OF GEOLOGY


in basic igneous rocks or by metamorphism of dolomite rocks; and it
usually occurs in foliated, granular or fibrous masses. Talc is used as a
filler, coating pigment, dusting agent, and in ceramics, rubber, plastics,
lubricants and talcum powder.

tar A thick, brown to black, viscous organic liquid, free of water,
which is obtained by condensing the volatile products of the destructive
distillation of coal, wood, oil, etc. It has a variable composition, depend-
ing on the temperature and material used to obtain it.

volatile matter In coal, those substances, other than moisture, that
are given off as gas and vapor during combustion. Standardized labora-
tory methods are used in analysis. Syn: volatiles; volatile combustible.

wet carbonization A process in which a peat slurry is heated to
572-7520F at 50-100 atmospheres of pressure; produces a "peat
coal" with a heat content of 12,000- 14,000 BTU/lb dry weight.

wetland Areas inundated or saturated by surface water or ground-
water at a frequency and duration to support, and that under normal
circumstances do support, a prevalence of vegetation typically adapted
for life in saturated soil conditions. Wetlands can often be a transition
zone between aquatic and terrestrial communities.

wet mining methods See hydraulic peat mining.

wet oxidation Process for oxidation of many wet organic materials in
which air or oxygen is fed to the wet organic material in a closed, heated
vessel. Combustion is controlled by the rate of oxygen feed and can be
carried to completion to produce energy or can be stopped after the
material is carbonized.

wet reclamation Any reclamation process which results in a perma-
nently or periodically flooded reclaimed area.

Definitions and information on terms in this glossary are taken from the
following references:

Brown, et al., 1983
Dravo Engineers and Constructors, 1981
Fuchsman, 1978
Gary, et al., 1974
U.S. Department of Energy, 1979
Langbein and Iseri, 1960


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