A dressed product of copper works in South America, consisting of grains
of native copper mixed with pyrite, chalcopyrite, mispickel, and earthy
minerals. See also:copper barilla; barilla.
A new drill hole pattern in which two overlapping holes of diameter about
2-1/4 in (5.7 cm) are drilled in the tunnel center and left uncharged.
These holes form a slot roughly 4 in by 2 in (10.2 cm by 5.1 cm) to which
the easers can break. All the holes in the round are parallel and in line
with the tunnel. Short-delay detonators are used for the easer holes and
1/2-s delays for the rest of the round. A pull of 10 ft (3.0 m) per round
has been obtained in strong rock with 10.5-ft (3.2-m) holes. Explosive
consumption for the easer holes is about 0.2 lb/ft (0.3 kg/m) of hole.
Nelson
a. A microscopic zone of minerals, usually arranged radially around
another mineral. The term has been applied to reaction rims, corrosion
rims, and originally crystallized minerals. AGI
b. A Spanish term meaning crown. Sometimes used in the Southwestern United
States as a syn. for diamond bit. Long
c. Rim of alteration product surrounding an earlier formed crystal,
commonly the result of reaction with a cooling magma.
Syn:kelyphitic rim; kelyphite; reaction border; kelyphytic rim.
See also:reaction rim
A monoclinic mineral, Pb(Mn4+ ,Mn2+ )8 O16;
cryptomelane group; pseudotetragonal; at the Coronado vein,
Clifton-Morenci district, AZ.
A rock containing mineral grains surrounded by coronas. AGI
a. A process of erosion whereby rocks and soil are mechanically removed or
worn away by the abrasive action of solid materials moved along by wind,
waves, running water, glaciers, or gravity. Syn:abrasion; attrition.
AGI
b. A term formerly used as a syn. of corrosion, or as including the work
of corrosion. AGI
corrected effective temperature
The scales of effective temperature take into consideration the
temperature, humidity, and speed of the air. The effects of radiant heat
can be included in an assessment of effective temperature by using the
globe thermometer temperature instead of the dry-bulb temperature in those
cases when the reading of the globe thermometer is higher than the
dry-bulb temperature. In such cases, the result is described as the
corrected effective temperature. Roberts, 1
A deflection wedge used to deflect a crooked borehole back into its
intended course. See also:deflecting wedge
A chart, graph, or table giving the true angle of the inclination of a
borehole for specific apparent angles as read from the etch line in a
specific-size acid bottle. See also:capillarity-correction chart
Long
a. Material correctly included in the products of a sizing or density
separation. BS, 5
b. In cleaning, the material of specific gravity lower than the separation
density that has been included in the low-density product, or material of
specific gravity higher than the separation density that has been included
in the high-density product. BS, 5
a. To show correspondence in character and stratigraphic position between
such geologic phenomena as formations or fossil faunas of two or more
separated areas. Adj. belonging to the same stratigraphic position or
level. AGI
b. To establish a definite stratigraphic relationship between strata that
are separated by distance or by geologic disturbance; e.g., to find which
coalbeds in one coalfield or part thereof correspond with (or are the same
as) those of another coalfield.
c. To plot or to arrange two surveys, the surveys of two mines, or the
underground and the surface, on the same base line or to a common
meridian. Mason
a. The determination of the equivalence in geologic age and/or
stratigraphic position of two formations or other stratigraphic units in
separated areas; or, more broadly, the determination of the
contemporaneity of events in the geologic histories of two areas. Fossils
constitute the chief evidence in problems of such correlation.
See also:lithologic correlation
b. The identification of a phase of a seismic record as representing the
same phase on another record, thus relating reflections from the same
stratigraphic sequence or refractions from the same marker. AGI
A seismic shooting method in which isolated profiles are shot and
correlated to obtain relative structural positions of the horizons mapped.
CF:continuous profiling
A clay mineral having 1:1 regular interstratification of trioctahedral
chlorite with either trioctahedral vermiculite or trioctahedral smectite.
See:methane drainage
a. To eat away by degrees as if by gnawing. Webster 3rd
b. To wear away or to diminish by gradually separating or destroying small
particles or converting into an easily disintegrated substance; esp., to
eat away or to diminish by acid or alkali reaction or by chemical
alteration. Webster 3rd
A phenocryst that after crystallization is more or less reabsorbed or
attacked by the magma, or a crystal in a vein or a pegmatite that is
partly dissolved by later solutions. The process is probably much the same
in all three instances. Hess
Lead of purity exceeding 99.94% , suitable for the production of white
lead. CTD
a. A process of erosion whereby rocks and soil are removed or worn away by
natural chemical processes, esp. by the solvent action of running water,
but also by other reactions such as hydrolysis, hydration, carbonation,
and oxidation. Syn:chemical erosion
b. A term formerly used interchangeably with corrasion for the erosion of
land or rock, including both mechanical and chemical processes. The
mechanical part is now properly restricted to corrasion and the chemical
to corrosion. Verb: corrode. AGI
c. See:magmatic corrosion; abrasion. See also:attrition