The old fabulous deposit, discovered in surface croppings, easy of
exploitation, and capable of financing its own development as it went
along. Hoover
Inadequately financed operation, depending on hand-to-mouth existence.
Mining from surface down to bedrock. At grass; at surface. Also known as
mining on a shoestring. Pryor, 3
a. A screen or sieve for use with stamp mortars for grading ore.
Webster 3rd
b. A frame, bed, or a kind of basket of iron bars for holding fuel while
burning. Webster 3rd
a. A bar forming part of a fire grate. Standard, 2
b. One of the bars forming a coarse screen or grizzly. Fay
Formerly, coal passing through bars 3-1/4 to 4-1/4 in (8.3 to 10.8 cm)
apart and over 2-1/4 in (6.7 cm) round holes. In Arkansas, the bars are 7
in (17.8 cm) apart and the holes are 3 to 3-1/4 in (7.6 to 8.3 cm) in
diameter. Fay
A laborer who replaces grates on conveyors after roasted lead ore has been
dumped into cars, using hooks. Lead ore is loaded on grates and conveyed
through a furnace in which the sulfur is driven off by roasting prior to
the ore being melted to separate and recover the lead in another furnace.
DOT
a. A network of lines representing geographic parallels and meridians
forming a map projection.
b. A template divided into blocks or cells, for graphically integrating a
quantity such as gravity. Graticules are used in computing terrain
corrections and the gravitational or magnetic attraction of irregular
masses. AGI
c. An accessory to an optical instrument such as a microscope to aid in
measurement of the object under study; it is a thin glass disk bearing a
scale which is superimposed upon the object. AGI
d. The network of lines representing meridians of longitude and parallels
of latitude on a map or chart, upon which the map or chart was drawn. Not
to be confused with grid. AGI
a. A coarse screen made of parallel or crossed bars to prevent passing of
oversized material.
b. A series of parallel and crossed bars used as platform or walkway
floors or as coverings for pits and trenches over which traffic can pass;
generally removable to permit access to conveying equipment for servicing.
c. A series of parallel and/or crossed bar units fastened to or propelled
by a conveying medium, used for carrying large lump-size bulk material or
objects. They usually permit passage of air for cooling or for heat to
maintain temperature.
d. The act of sorting ores by means of grates.
a. An unconsolidated, natural accumulation of rounded rock fragments
resulting from erosion, consisting predominantly of particles larger than
sand (diameter greater than 2 mm or 1/12 in), such as boulders, cobbles,
pebbles, granules, or any combination of these. See also:pebble
AGI
b. A popular term for a loose accumulation of rock fragments, such as a
detrital sediment associated esp. with streams or beaches, composed
predominantly of more or less rounded pebbles and small stones, and mixed
with sand that may compose 50% to 70% of the total mass. AGI
c. An engineering term for rounded fragments having a diameter in the
range of 1.87 in (47.5 mm) (retained on U.S. standard sieve No. 4) to 3 in
(76 mm). AGI
A natural mound or exposed face of gravel, particularly such a place from
which gravel is dug; a gravel pit. Hess
See:alluvium
S. Afr. A mine extracting gold from sand or gravel; also called placer
mine. See also:gravel pit
A pit from which gravel is obtained. See also:gravel mine
Standard, 2
Placers along the coastal plain of the Seward Peninsula, AK.
Very coarse gunpowder. Standard, 2
A centrifugal pump with renewable impellers and lining, suitable for
pumping a mixture of gravel and water. Rubber is sometimes used as lining
to the pump and pipes owing to its high resistance to abrasion.
See also:sand pump
A method of alluvial mining that consists of (1) excavating and breaking
up the gravel bank by using giants or monitors, (2) washing the
disintegrated material into a sump, excavated in the bedrock, (3)
elevating the mixture from the sump to an elevated line of sluices by
means of a gravel pump, and (4) sluicing the gravel for the recovery of
its mineral content. Griffith
A natural paraffin. See also:hatchettite
a. An instrument to measure the value of gravity or for measuring
variations in the magnitude of the Earth's gravitational field.
Measurements of gravity are accomplished generally by one of three
methods: dropped ball, pendulum, or spring gravimeter. The latter type of
gravimeter, which is based upon the principle of the weighted
spring--where the length or measured variations in the length of the
spring are a function of the gravitational field at different locations,
is the type widely used today. See also:Graf sea gravimeter;
gravitational prospecting. Hunt
b. An instrument for determining specific gravities, particularly of
liquids. See also:hydrometer
c. An instrument that measures variations in the density of underlying
rocks. BS, 9
d. An instrument for measuring variations in the gravitational field,
generally by registering differences in the weight of a constant mass as
the gravimeter is moved from place to place. Syn:gravity meter
See also:astatic gravimeter
Quantitative chemical analysis in which the different substances of a
compound are measured by weight. AGI