A rock composed of materials derived from the weathering of older rocks; a
sedimentary rock, or a rock formed of material that has not been in a
state of fusion immediately before its accumulation. AGI
Representation of crystal structures in terms of a master structure, e.g.,
feldspar as derivative of coesite with aluminum replacing tetrahedral
silicon and charge balance maintained by intertetrahedral alkali and
alkali-earth ions.
A fossil that is not native to the rock in which it is found, e.g., a
fossil found as a pebble in a conglomerate.
A fuel obtained from a raw fuel by some process of preparation for use,
for example, coke, charcoal, benzene, and gasoline. Nelson
A skin disease caused by the application of dust or liquids. In coal
mining, the dusts may be coal or stone dust and the liquids may be mine
waters, oil or grease, perspiration and acids or alkalis. The majority of
cases occur in deep and hot mines having high wet-bulb temperatures.
Mason
a. The framed wood or steel tower placed over a borehole to support the
drilling tools for hoisting and pulling drill rods, casing, or pipe.
Sometimes incorrectly called a tower. Long
b. The framework over a borehole, used primarily to allow lengths of drill
rod to be added to the drilling column. BS, 9
c. A three- (or more) legged framework for supporting drill rods and
tackle in deep boring; a temporary three-legged headframe, or headgear,
for a shaft. Mason
A crane in which the top of the post is supported by fixed stays in the
rear and the jib is pivoted like the boom of a derrick.
See also:derricking jib crane
A jib crane in which the inclination of the jib, and hence the radius of
action, can be varied by shortening or lengthening the tie ropes between
the post and the jib. CTD
The rope used for supporting and hoisting the boom on jib cranes and
excavators. Hammond
Any process for making potable water from sea water or other saline
waters. Distillation is the oldest method. Others involve electrodialysis,
freezing, extraction, and ion exchange. Also called desalination.
A ventilation system in which the downcast air is conducted to the top end
of the workings (in inclined workings) and it then flows downhill from
level to level. In deep mines, the system helps to keep the faces cool.
See also:ascensional ventilation; homotropal ventilation;
antitropal ventilation.
A theory of formation of supergene mineral deposits involving the descent
from above of mineral-bearing solutions. The theory originated with the
Neptunian school of thought of the 18th century, which postulated an
aqueous origin for all rocks. CF:ascension theory
a. An orthorhombic mineral, 4[PbZn(VO4 )(OH)] having Zn replaced by
Cu toward mottramite; greasy; varicolored; in oxidized zones of ore
deposits; a source of vanadium. Syn:vanadite
b. The mineral group arsendescloizite, cechite, descloizite, mottramite,
and pyrobelonite.
The classification, composition, properties, trade grades, sources, and
the methods of recovery, fashioning, and use of gem minerals and gem
materials and their substitutes. See also:gemology
That branch of mineralogy devoted to the description of the physical and
chemical properties of minerals. Fay
Removal by chipping of surface blemishes from ingots or blooms.
Pryor, 3
a. A hard layer, containing calcium carbonate, gypsum, or other binding
matter, exposed at the surface in a desert region. AGI
b. Desert varnish. AGI
c. Desert pavement. AGI
See:obsidian; moldavite.
All lands exclusive of timber lands and mineral lands that will not,
without irrigation, produce some agricultural crop. Ricketts
A natural residual concentration of wind-polished pebbles, boulders, and
other rock fragments, mantling a desert surface where wind action and
sheetwash have removed all smaller particles, and usually protecting the
underlying finer-grained material from further deflation. The fragments
commonly are cemented by mineral matter. Syn:desert crust
See also:lag gravel
In the Western United States, a prospector, esp. one who works and lives
in the desert, or who has spent much time in arid regions. The name is
derived from a small rodent common throughout much of the Great Basin and
Southwestern United States. Fay