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Bartlett table

A three-shelf table driven by an eccentric that gives it a vanning motion.
Ore and water are fed on the upper shelf, giving two products, heads and
tailings. The latter are retreated on the second shelf, and the tailings
go to the third or lower shelf for retreatment. Liddell

Barvoys process

A sink-float process in which the medium is a suspension of clay from the
raw coal and minus 200- or 300-mesh barite in water, with the volume of
the clay usually equal to about twice that of the barite. Barite clay and
coal suspensions can be regulated to get effective washing gravities from
1.2 to 1.8. Sizes from run-of-mine to one-eighth inch may be cleaned by
this process, which has been widely adopted in Europe. Also known as the
Sophia-Jacoba process in German publications. Mitchell

barylite

An orthorhombic mineral, BaBe2 Si2 O7 ; forms hard (6
to 7 on the Mohs scale), colorless crystals; at Laangban, Sweden;
Franklin, NJ; and Park County, CO.

barysilite

A white trigonal mineral, Pb8 Mn(Si2 O7 )3 ;
occurs at Laangban, Sweden, and Franklin, NJ.

barysphere

The interior of the Earth beneath the lithosphere, including both the
mantle and the core. However, it is sometimes used to refer only to the
core or only to the mantle. Syn:centrosphere

baryta

Barium oxide; BaO. AGI

barytes

See:barite

barytocalcite

a. A monoclinic mineral, BaCa(CO3 )2 ; trimorphous with
alstonite and paralstonite.
b. A mixture of calcite and barite.

basal arkose

An arkosic sandstone basal to a sedimentary sequence, resting
unconformably on a granitic terrane; the arkosic equivalent of a granitic
basal conglomerate. AGI

basal cleavage

Mineral cleavage parallel to the basal pinacoid that is normal to the c
crystallographic axis. Also called pinacoidal cleavage.

basal conglomerate

A well-sorted, lithologically homogeneous conglomerate that forms the
bottom stratigraphic unit of a sedimentary series and that rests on a
surface of erosion, thereby marking an unconformity; esp. a coarse-grained
beach deposit of an encroaching or transgressive sea. It commonly occurs
as a relatively thin, widespread or patchy sheet, interbedded with quartz
sandstone. AGI

basal pinacoid

A pinacoid of two parallel faces that intersect only the c
crystallographic axis. Also called a base. Syn:basal plane

basal plane

a. A plane perpendicular to the c, or principal, axis in a tetragonal or
hexagonal structure. ASM, 1
b. Syn:basal pinacoid

basal reef

S. Afr. A gold-bearing reef regarded as the principal carrier of gold in
the Orange Free State. It has been associated with the Elsburg series of
the central Witwatersrand and occurs below what has become known as the
leader reef. Beerman

basalt

A general term for dark-colored mafic igneous rocks, commonly extrusive
but locally intrusive (e.g., as dikes), composed chiefly of calcic
plagioclase and clinopyroxene; the fine-grained equivalent of gabbro.
Nepheline, olivine, orthopyroxene, or quartz may be present. Adj.
basaltic. CF:tholeiite

basal thrust plane

The sole fault underlying a series of overthrusts.

basaltic

Pertaining to, made of, or resembling basalt; as, basaltic lava.
See also:basalt

basaltic dome

See:shield volcano

basaltic hornblende

A variety of hornblende containing ferric (oxidized) iron in basalts and
other basic igneous (volcanic) rocks.

basaltic layer

See:sima

basaltine

See:augite