That component of the stress in a rock mass that acts perpendicular to the
lode plane or any other reference plane. Spalding
a. Normal temperature and pressure are taken as 0 degrees C (273 degrees
absolute) and 30 in (760 mm) of mercury pressure. Also called standard
temperature. Cooper
b. As applied to laboratory observations of the physical characteristics
of bituminous materials, it is 77 degrees F (25 degrees C).
Urquhart
A theory claiming that the removal of a coal seam caused the overlying
strata to fracture at right angles to the inclination of the beds.
Subsidence observations do not support this theory.
See also:dome theory
In fan shooting, a time-distance curve obtained along a profile in some
nearby area that does not contain geologic structures of the type being
sought. AGI
The adj. of norm.
A mineral whose presence in a rock is theoretically possible on the basis
of certain chemical analyses. A normative mineral may or may not be
actually present in the rock. See also:norm
AGI
A system of classification and nomenclature of igneous rocks based on the
norm of each rock. It is used in detailed petrologic studies rather than
in ordinary geologic or mining work. Syn:CIPW system
A process for the direct production of iron sponge. A mixture of carbon
monoxide and hydrogen is used as the reducing agent. The equipment
consists of three vertical ovens, for preheating, reducing, and cooling
the charge, and apparatus for regenerating the spent gases. The ore is
contained in a series of muffle trays, each tray holding about 3 tons of
ore. These trays pass down through the preheating oven, where the ore is
heated to 1,000 degrees C, and are then transferred to the reducing oven,
where they are raised through and against the downward gas current, then
transferred to the cooling shaft, and slowly lowered down it. The transfer
of a tray from one oven to another is made without contact with air. The
ore is preheated in the first oven by part of the gases from the reduction
oven, and the sponge iron is cooled in the third oven to 50 degrees C by
cold gas from a gas holder. Osborne
A triclinic mineral, Al(OH)3 ; cryptocrystalline; a constituent of
strongly weathered soils, of laterites and bauxites.
York. The rise side of the coal in North Yorkshire.
The end of a magnet that points approx. north. The other end is the
south-seeking pole. Morris
Trade name for a dense-medium washer for treating coal lump size down to
about 1/8 in (3.2 mm). It comprises a shallow circular tank with a flat
base and a conical inner shell containing the driving mechanism. The clean
coal floats and passes over a weir while the shale sinks to the bottom and
is conveyed to an outlet chute. Its capacity ranges from about 50 st/h
(45.4 t/h) to over 500 st/h (454 t/h), depending on the size of the
vessel. Nelson
A variation of the ordinary cut that may be said to represent a
combination of the latter and the fan cut. The first drill holes are
formed with a sharper angle toward the working face, which facilitates
breaking. This type of cut has been employed successfully in headings of
small section, the cut hole being blasted first, followed by the bench
holes. In order to obtain the maximum possible advance the cut may also be
deepened after blasting, during the first pause in working, e.g, the whole
section then being broken out simultaneously. Fraenkel
a. Scot. A point; a projecting angle of coal or other mineral. Also called
ness. Fay
b. The lead face of the crown of a diamond bit. Long
c. A short plunging anticline without closure.
d. To dip or run in the form of a geological nose. Webster 3rd
An isometric mineral, Na8 Al6 Si6 O24 (SO (sub
4) ).H2 O ; sodalite group; occurs in silica- and lime-deficient
igneous rocks. Formerly called noselite, nosin, nosite.
Eng. A stratum is said to nose in when it dips beneath the ground into a
hillside in a V-form or nose form.
See:nosean
a. Eng. A nose-shaped stratum cropping out. Fay
b. To diminish by losing stratum after stratum and getting into the lower
part of the measure; said of a coal seam. Standard, 2
The inside nozzle of a tuyere. Standard, 2
See:nosean
See:nosean