In crystallography, the number of different families of planes having the
same form. Henderson
The rate of occurrence of accidents as determined by multiplying the
actual number of injuries in any given period by 200,000 and dividing the
product by the number of man-hours exposure. Syn:incidence rate
a. The percentage response of a seismic amplifier for various frequencies
at a given filter setting. AGI
b. Attenuation as a function of frequency produced by passage of a signal
through an element, such as a geophone or filter. AGI
Said of a rock or rock surface that has not been subjected to or altered
by surface weathering, such as a rock newly exposed by fracturing.
Syn:unweathered
Air free from the presence of deleterious gases. Pure air.
An underground station, located in the intake airway, that is used by
rescue teams during underground fires and rescue operations. The base
should be as close to the fire as safety will permit, adequately
ventilated, and in constant touch with the surface by telephone.
Nelson
a. A great rise in, or a sudden overflowing of, a small stream, usually
caused by heavy rains or rapidly melting snow in the highlands at the head
of the stream; a rapidly rising flood, usually of minor severity and short
duration. See also:flash flood
b. A small clear freshwater stream or current flowing swiftly into the
sea; an area of comparatively fresh water at or near the mouth of a stream
flowing into the sea. AGI
c. A small stream flowing swiftly into a lake (as in the spring) and often
carrying a heavy silt load during its peak flow. AGI
a. Water containing less than 1,000 mg/L of dissolved solids; generally,
water with more than 500 mg/L is undesirable for drinking and for many
industrial uses (Solley et al., 1983). AGI
b. In general usage, the water of streams and lakes unaffected by salt
water or salt-bearing rocks. Syn:sweet water
fresh-water. AGI
A limestone formed by accumulation or precipitation in a freshwater lake,
a stream, or a cave. It is often algal and sometimes nodular.
See also:underclay limestone
A tetragonal mineral, Ba2 TiSi2 O8 ; yellow with
yellow fluorescence; resembles idocrase.
A result of honeycomb weathering, consisting of small pits in a rock
surface that become fewer as they grow larger and deeper.
A monoclinic mineral, Na2 (Ti,Fe)8 O16 ; forms
pseudohexagonal crystals in an apatite-rich alkali pegmatite at
Katzenbuckel, Odenwald, Germany.
Iron plates suspended in dust chambers for the purpose of settling dust
and condensing fumes that escape from the furnace with the gases.
Fay
A rare-earth-rich variety of thorite from Brevik, Norway.
Tendency for particles to break down in size (degrade) during storage and
handling under the influence of light physical forces. Pryor, 3
a. Said of a rock or mineral that crumbles naturally or is easily broken,
pulverized, or reduced to powder, such as a soft or poorly cemented
sandstone. AGI
b. Said of a soil consistency in which moist soil material crushes easily
under gentle to moderate pressure (between thumb and forefinger) and
coheres when pressed together. AGI
See:gedanite
A rock that breaks easily or crumbles naturally; hence a formation from
which good core cannot be obtained easily. Long
Mechanical resistance to the relative motion of contiguous bodies or of a
body and a medium. AGI
Electrostatic charge developed by rubbing amber, tourmaline, topaz,
diamond, and some plastic imitations with a cloth.
The force required to overcome friction when a set of tubs or a run of
wagons is hauled along a level track at uniform speed. For ordinary pit
tubs the frictional force is about 40 lb/st (20 kg/t) load, and for mine
cars or wagons it is about 28 lb/st (14 kg/t) load. This resistance is
sometimes called traction. Morris