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arcwall machine

See:slabbing machine

arc welding

A group of welding processes wherein coalescence is produced by heating
with an electric arc or arcs, with or without the application of pressure
and with or without the use of filler metal. Coal Age, 2

Ardeer double-cartridge test

See:sensitivity to propagation

ardennite

a. A yellow to yellowish-brown vanadiosilicate of aluminum and manganese
that crystallizes in the orthorhombic system. Fay
b. An orthorhombic mineral, Mn4 (Al,Mg)6 (SiO4 ) (sub
2) (Si3 O10 )[(As,V)O4 ](OH)6 .

areal geology

The branch of geology that pertains to the distribution, position, and
form of the areas of the Earth's surface occupied by different types of
rock or by different geologic units, and to the making of geologic maps.
Fay

areal map

A geologic map showing the horizontal area or extent of rock units exposed
at the surface. AGI

areal pattern

A dispersion pattern resulting from widespread rock alteration. Such
patterns may outline the boundaries of a group of deposits and thus limit
the area that it is necessary to prospect in detail.

area of airway

In mine ventilation, the cross-sectional area of the entry or duct through
which the air flows; expressed in square meters.

area of influence of a well

The area surrounding a well within which the piezometric surface has been
lowered when pumping has produced the maximum steady rate of flow.
ASCE

area of settlement

The surface area affected by subsidence. Briggs

arenaceous

Said of a sediment or sedimentary rock consisting wholly or in part of
sand-sized fragments, or having a sandy texture or the appearance of sand;
pertaining to sand or arenite. Also said of the texture of such a sediment
or rock. The term implies no special composition and should not be used as
a syn. of siliceous. Syn:sandy

areng

A Bornean term for a yellowish gravelly earth, sometimes containing
diamonds.

arenite

a. A general name for sedimentary rocks composed of sand-sized fragments
irrespective of composition; e.g., sandstone, graywacke, arkose, and
calcarenite. AGI
b. A clean sandstone that is well sorted, contains little or no matrix
material, and has a relatively simple mineralogic composition; specif. a
pure or nearly pure, chemically cemented sandstone containing less than
10% argillaceous matrix and inferred to represent a slowly deposited
sediment well-washed by currents.---Etymol: Latin arena, sand. Adj.
arenitic. See also:lutite

Arents tap

An arrangement by which molten lead from the crucible of a shaft furnace
is drawn through an inverted siphon into an exterior basin from which it
can be ladled without disturbing the furnace. Syn:siphon tap
Fay

arfvedsonite

A monoclinic mineral, Na3 (Fe+2 ,Mg)4 Fe+3
Si8 O22 (OH)2 , of the amphibole group; dark green to
black; in silica-poor igneous rocks.

Argall furnace

A reverberatory roasting furnace the hearth of which has a reciprocating
movement whereby the ore is caused to move forward by the action of
rabbles extending across the hearth. Fay

Argall tubular furnace

A tubular roasting furnace consisting of four brick-lined steel tubes 30
ft (9.1 m) long nested together inside two steel tires, which revolve upon
steel-faced carrying rolls. Fay

argental mercury

See:amalgam

argentate

a. A salt in which silver acts as an acid radical; e.g., ammonium
argentate (fulminating silver). Standard, 2
b. Having a silvery appearance. CTD

argentation

The act or process of coating or plating with silver. Standard, 2

argentiferous

Containing silver.