A descriptive term for those changes produced by contact metamorphism in
the wall rock of the intrusion; opposite of endomorphic.
See:exomorphism
See:exomorphism
Changes in country rock produced by the intense heat and other properties
of magma or lava in contact with them; it is a form of contact
metamorphism in the usual sense. The term was originated by Fournet in
1867. CF:endomorphism
AGI
Applied to a boulder, block, or larger rock body unrelated to the rocks
with which it is now associated, which has been moved from its place of
origin by one of several processes. Exotic masses of tectonic origin are
also allochthonous; those of glacial or ice-rafted origin are generally
called erratics. AGI
Limonite precipitated in rock that did not formerly contain any
iron-bearing sulfide. CF:indigenous limonite
The lightweight cellular material obtained by controlled processing of
molten blast-furnace slag with water or with water and other agents, such
as steam or compressed air or both. ASTM
A geophysical test based on the resistivity method to determine
underground geological structure. Nelson
A reamer capable of slight adjustment in diameter by means of a coned
internal plug acting in a partially split length of the tool.
Nelson
A channel or groove incised into and across the face of a bit, the depth
and/or width of which gradually increases from the inside to the outside
walls of the bit. Long
A drill bit that may be adjusted to cut various sizes of holes. The
adjustment of some types may be accomplished by mechanical means while the
bit is inside the borehole. Also called paddy; paddy bit. Long
A bolt equipped with a split casing that acts as a wedge; used for
attaching to brick or concrete. Crispin
A borehole drill bit having cutters that may be expanded to cut a larger
size hole than the size of the bit in its unexpanded state; also, a device
equipped with cutters that may be expanded inside casing or pipe to sever,
or cut slits or holes in, the casing or pipe. CF:paddy
Imaginary dome of rock above underground working, matched by a similar
inverted dome below the stope. The dome lies inside the zone of stress due
to an unsupported ground, but it is partially destressed owing to
expansion and peripheral transfer of load. Pryor, 3
In petrology, one of a system of fissures that radiate irregularly through
feldspar and other minerals adjacent to olivine crystals that have been
replaced by serpentine. The alteration of olivine to serpentine involves
considerable increase in volume, and the stresses so produced are relieved
by the fissuring of the surrounding minerals. This phenomenon is common in
norite and gabbro. AGI
Either a bend like the letter U or a coil in a line of pipe to provide for
expansion or contraction. Fay
A hoop or ring of U-section used to join lengths of pipe so as to permit
of expansion. Fay
The calculated tonnage of recoverable ore in the mine. Lewis
A normal longwall face on which new machines, such as a cutter loader, may
be put to work to gain experience and perhaps improved. Such trials may
disclose weaknesses, and they would also indicate the best support system,
turnover, and other operating factors. See also:standby face
Syn:trial face
The study of chemical and isotopic variations in minerals as a function of
temperature and pressure. CF:chemical mineralogy; crystallogeny;
phase equilibria.
a. A cap or fulminating cartridge, placed in a charge of gunpowder or
other explosive, and exploded by electricity or by a fuse. Also called
detonator. Syn:battery
b. Electric shot-firing apparatus specially designed to provide a source
of electric energy of sufficient power to fire electric detonators. Each
type of exploder is designed to fire a specific number of shots in series,
and exploders are rated accordingly; e.g., single-shot exploders, 30-shot
exploders, and 100-shot exploders. See also:Beethoven exploder
Syn:blasting unit
c. A chemical employed for the instantaneous explosion of powder.
Zern