a. Corn. The boards or lagging put behind a frame of timber. Fay
b. Corn. Pieces of timber about 4 ft 6 in by 6 in by 2 in (1.4 m by 15 cm
by 5 cm) with end sharpened or beveled to give the lath an upward trend
when being driven into the roof gravels. A number of laths driven into the
roof form a protective shield for the miners working in the face. Also
called lagging. Eng. Min. J., 1
A porphyritic extrusive rock having phenocrysts of plagioclase and
potassium feldspar in nearly equal amounts, little or no quartz, and a
finely crystalline to glassy groundmass, which may contain obscure
potassium feldspar; the extrusive equivalent of monzonite. Latite grades
into trachyte with an increase in the alkali feldspar content, and into
andesite or basalt, depending on the presence of sodic or calcic
plagioclase, as the alkali feldspar content decreases. It is usually
considered synonymous with trachyandesite and trachybasalt, depending on
the color. The name, given by Ransome in 1898, is derived from Latium,
Italy. AGI
a. The north-south correction made to observed magnetic-field intensity in
order to remove the Earth's normal field (leaving, as the remainder, the
anomalous field). AGI
b. A correction of gravity data with latitude, because of variations in
centrifugal force owing to the Earth's rotation and because of differences
in the radius owing to polar flattening. The correction for latitude phi
amounts to 1.308 sin 2 phi mgal/mi = 0.813 sin 2 phi mgal/km. AGI
See:laterite
A pink anorthite from Amitok Island, LB, Canada. Standard, 2
Metal in thin sheets, esp. (and originally) brass, which in this form is
also called latten brass. Standard, 2
An array of points in space such that each point is in an identical point
environment. Thus, any straight line drawn between any two points in a
lattice and continued will pass at equal intervals through a succession of
similar points. Fourteen possible lattices exist. Syn:Bravais lattice;
space lattice. CF:net; row.
Energy required to separate the ions of an ionic crystal to an infinite
distance from each other. Pryor, 3
An open girder, beam, or column in timber, steel, or aluminum alloy, built
up from structural members joined and braced together by intersecting
diagonal bars. See also:space lattice
Lattice parameters are the unit lengths along each crystallographic axis
and their interaxial angles. See also:axial element
a. In mineral deposits, a texture produced by exsolution in which elongate
crystals are arranged along structural planes. AGI
b. A texture that is typical of the mineral serpentine in a rock where it
replaces an amphibole. CF:knitted texture
a. Water that is an integral part of the clay structure. This structural
water (OH lattice water) is not to be confused with interlayer water. The
lattice water can be removed by heating in the range of about 450 to 600
degrees C. ACSG, 2
b. Molecular water at specific lattice sites. Van Vlack
See:natrolite.
Alternate spelling of laubanite.
See:Laue photograph
A triclinic mineral, MnFe2 (PO4 )2 (OH)2 .8H
2 O ; dimorphous with stewartite.
A collection of X-ray diffraction spots made by a crystal using a Laue
camera and white radiation. Syn:Laue diagram
a. A flume, trough, channel, or chute by which water or powdered ore is
conveyed in a mining operation. AGI
b. An inclined channel, lined with refractory material, for the conveyance
of molten steel from the furnace taphole to a ladle. Also spelled lander.
Dodd
In ore dressing, smelting, and refining, a laborer who maintains and
repairs the launders (long boxes), used to convey water and mill pulp
between the various units of ore-treating equipment in a mill. DOT
A screen used for the sizing and dewatering of small sizes of anthracite.
Mitchell