A dark-colored intrusive rock composed of alkali feldspar, labradorite,
pyroxene, biotite, iron oxides, apatite, and possibly a small amount of
nepheline. It is essentially a monzonite. Its name, given by Johannsen in
1938, is derived from the Highwood Mountains, MT. Not recommended usage.
AGI
Hydrated chloroborate of calcium, Ca2 B5 O9 Cl.H (sub
2) O , as colorless monoclinic-domatic crystals in the rock salt of
Louisiana. See also:parahilgardite
a. An arch or high place in a mine. Fay
b. Scot. The surface at a mine. Fay
c. N. of Eng.; Mid. An underground inclined plane. Fay
d. A natural elevation of land of local area and well-defined outline.
Webster 3rd
Applied to the ridges and hollows along the surface of dumped material
(usually overburden) at an opencast mine. The undulations are leveled out
when the land is restored. Nelson
A small, low hill; a mound. Adj: hillocky. AGI
Peat formed in mountainous districts and characterized by the presence of
Sphagnum, Andromeda, heath, pine trees, etc. Tomkeieff
a. Used to describe quarries when located in high slopes.
CF:terrain slope
b. A part of a hill between its crest and the drainage line at the foot of
the hill. Syn:hillslope
Gravel deposits intermediate between the creek and bench gravels; their
bedrock is slightly above the creek bed, and the surface topography shows
no indication of benching.
A quarry cut into and along the hillside; may comprise a single face or a
series of benches. If the depth of face is not more than about 30 ft (9 m)
it can be worked in one cut, but deeper faces are usually worked in two or
more benches. See also:pit quarry
See:hillside
A generalization that states that, in a vertical sequence at any given
point in the coalfield, the rank of the coal of the successive seams rises
with increasing depth. Although this statement is generally true, there
are numerous departures from it. Tomkeieff; Nelson
a. In classification, when the minerals settle in a thick pulp, as opposed
to free settling in which the free particles fall through fluid media.
Newton, 1
b. Settlement of particles through a crowded zone, usually in a hydraulic
column through which their fall is opposed by rising water.
Pryor, 2
The ratio of the apparent specific gravities of the mineral against the
suspension (not against the liquid) raised to a power between one-half and
unity. Gaudin, 1
A fine-grained sandstone used extensively in the manufacture of very cheap
sharpening stones, esp. axstones. Found in Indiana. Fay
The locus of maximum curvature or bending in a folded surface, usually a
line. Syn:flexure
See:apron conveyor
An apron pan that is made with a hinge construction along each edge so
that it may be joined to companion pans by a hinge pin or through a rod.
Steel bars placed in contact with the roof and at right angles to the
longwall face. They are usually supported by yielding steel props. The bar
can be extended to support newly exposed roof by adding another bar, which
can be locked onto it by a simple wedge or pin arrangement. The hinged bar
is widely used on conveyor faces in continuous mining. Nelson
See:Williams' hinged-hammer crusher
A fault on which the movement of one side hinges about an axis
perpendicular to the fault plane; displacement increases with distance
from the hinge. It is a questionable term. CF:scissor fault;
rotational fault. AGI
a. A subjective term referring to the relatively undisturbed terrain on
the back of a folded mountain range; i.e., the side away from which the
thrusting and folding appears to have taken place.
b. The land that lies behind a seaport or seaboard and supplies the bulk
of its exports and absorbs the bulk of its imports.