The release of energy in the superincumbent strata above the seam, induced
by the extraction of the seam. Sinclair, 2
The attachments to a crane that enable it to work as an excavator, a
skimmer, a back acter, or a similar machine. See also:jib
Hammond
a. A tractor loader with a digging bucket mounted and operated at the
front end of the tractor. Nichols, 1
b. A tractor loader that both digs and dumps in front.
See also:tractor shovel
See:foreland
A monoclinic mineral, PdBi2 ; forms minute metallic grains in mill
concentrates at the Frood Mine, Sudbury, ON, Canada.
a. The mechanical weathering process caused by repeated cycles of freezing
and thawing of water in pores, cracks, and other openings, usually at the
surface. AGI
b. The resulting effects of frost action on materials and structures.
Syn:freeze-thaw action; frost splitting. AGI
A fine-grained soil that undergoes changes in volume and bearing capacity
due to frost action (Nelson & Nelson, 1967). AGI
a. A local accumulation of excess water and mud liberated from ground ice
by accelerated spring thawing, softening the soil and causing a quagmire.
AGI
b. A break in a surface pavement due to swelling frost action; as the ice
melts, soupy subgrade materials issue from the break. AGI
A nearly vertical fracture developed by thermal contraction in rock or in
frozen ground with appreciable ice content. Frost cracks commonly
intersect to form polygonal patterns in plan view. AGI
Soil creep resulting from frost action.
An astatic gravity meter of the balance type, consisting of a mass at the
end of a nearly vertical arm, supported by a main spring inclined to the
vertical at about a 45 degrees angle. The beam rises and falls with
gravity variation, but is restored to its normal position by a sensitive
weighing spring tensioned by a micrometer screw. AGI
The uneven upward movement, and general distortion, of soils, rocks,
vegetation, and structures such as pavements, due to subsurface freezing
of water and growth of ice masses (esp. ice lenses); any upheaval of
ground caused by freezing. AGI
a. A lusterless ground-glass or mat surface on rounded mineral grains,
esp. of quartz. It may result from innumerable impacts of other grains
during wind action or from deposition of many microscopic crystals; e.g.,
fine silica secondarily deposited on quartz grains. AGI
b. The process that produces such a surface. AGI
a. The maximum depth of frozen ground in areas where there is no
permafrost; it may be expressed for a given winter, as the average of
several winters, or as the greatest depth on record. AGI
b. The bottom limit of permafrost. AGI
c. The altitudinal limit below which frost never occurs; applied esp. in
tropical regions. AGI
A general term for a knoll, hummock, or conical mound in a permafrost
region, containing a core of ice; represents a generally seasonal and
localized upwarp of the land surface, caused by frost heaving and/or
hydrostatic pressure of ground water. AGI
A short, heavy iron pin used by surveyors to make a hole in frozen ground
so that a wooden peg may be driven without breaking. Fay
The breaking of rock by water freezing in cracks. Syn:frost action;
frost weathering; frost wedging.
See:frost splitting
See:frost splitting
In the flotation process, a collection of bubbles resulting from
agitation, the bubbles being the agency for raising (floating) the
particles of ore to the surface of the cell. Hess
A substance used in a flotation process to make air bubbles sufficiently
permanent, principally by reducing surface tension.
See also:frothing agent